text:
Numerical Simulation of Non-Fickian Transport in Geological Formations with Multiple-Scale Heterogeneities
A. Cortis; C. Gallo; H. Scher; B. Berkowitz
We develop a numerical method to model contaminant transport in heterogeneous geological formations. The method is based on a unified framework that quantifies non-Fickian and Fickian transport - and the transition between them - over a broad range of temporal and spatial scales. As such, the method takes into account the different levels of uncertainty often associated with characterizing heterogeneities
Numerical simulation of non-Fickian transport in geological formations with multiple-scale heterogeneities
A. Cortis; C. Gallo; H. Scher; B. Berkowitz
We develop a numerical method to model contaminant transport in heterogeneous geological formations. The method is based on a unified framework that quantifies non-Fickian and Fickian transport - and the transition between them - over a broad range of temporal and spatial scales. As such, the method takes into account the different levels of uncertainty often associated with characterizing heterogeneities
Heterogeneity-enhanced gas phase formation in shallow aquifers during leakage of CO2-saturated water from geologic sequestration sites
NASA Astrophysics Data System (ADS)
Plampin, Michael R.; Lassen, Rune N.; Sakaki, Toshihiro; Porter, Mark L.; Pawar, Rajesh J.; Jensen, Karsten H.; Illangasekare, Tissa H.
A primary concern for geologic carbon storage is the potential for leakage of stored carbon dioxide (CO2) into the shallow subsurface where it could degrade the quality of groundwater and surface water. In order to predict and mitigate the potentially negative impacts of CO2 leakage, it is important to understand the physical processes that CO2 will undergo as it moves through naturally heterogeneous porous media formations. Previous studies have shown that heterogeneity can enhance the evolution of gas phase CO2 in some cases, but the conditions under which this occurs have not yet been quantitatively defined, nor tested through laboratory experiments. This study quantitatively investigates the effects of geologic heterogeneity on the process of gas phase CO2 evolution in shallow aquifers through an extensive set of experiments conducted in a column that was packed with layers of various test sands. Soil moisture sensors were utilized to observe the formation of gas phase near the porous media interfaces. Results indicate that the conditions under which heterogeneity controls gas phase evolution can be successfully predicted through analysis of simple parameters, including the dissolved CO2 concentration in the flowing water, the distance between the heterogeneity and the leakage location, and some fundamental properties of the porous media. Results also show that interfaces where a less permeable material overlies a more permeable material affect gas phase evolution more significantly than interfaces with the opposite layering.
X-ray micro-diffraction studies of heterogeneous interfaces between cementitious materials and geological formations
NASA Astrophysics Data System (ADS)
Dõhn, R.; Popov, D.; Schaub, Ph.; Pattison, P.; Grolimund, D.; Mõder, U.; Jenni, A.; Wieland, E.
In the present study the challenge of analyzing complex micro X-ray diffraction (microXRD) patterns from cement-clay interfaces has been addressed. In order to extract the maximum information concerning both the spatial distribution and the crystal structure type associated with each of the many diffracting grains in heterogeneous, polycrystalline samples, an approach has been developed in which microXRD was applied to thin sections which were rotated in the X-ray beam. The data analysis, performed on microXRD patterns collected from a filled vein of a cement-clay interface from the natural analogue in Maqarin (Jordan), and a sample from a two-year-old altered interface between cement and argillaceous rock, demonstrate the potential of this method.
Formation evaluation: Geological procedures
Whittaker, A.
This volume goes beyond a discussion of petroleum geology and the techniques of hydrocarbon (oil and gas) logging as a reservoir evaluation tool. It provides the logging geologist with a review of geological techniques and classification systems that will ensure the maximum development of communicable geological information. Contents include: 1. Introduction--cuttings recovery, cutting sampling, core sampling, rock classification; 2. Detrital rocks--classification, description; 3. Carbonate rocks--classification, description; 4. Chemical rocks-introduction, siliceous rocks, ferruginous rocks, aluminous rocks, phosphatic rocks, aluminous rocks, carbonaceous rocks; 5. Igneous and metamorpbic rocks; Appendix; References and Index.
Heterogeneity and Scaling in Geologic Media
Gregory N. Boitnott; Gilles Y. Bussod; Paul N. Hagin; Stephen R. Brown
The accurate characterization and remediation of contaminated subsurface environments requires the detailed knowledge of subsurface structures and flow paths. Enormous resources are invested in scoping and characterizing sites using core sampling, 3-D geophysical surveys, well tests, etc.... Unfortunately, much of the information acquired is lost to compromises and simplifications made in constructing numerical grids for the simulators used to predict flow and transport from the contaminated area to the accessible environment. In rocks and soils, the bulk geophysical and transport properties of the matrix and of fracture systems are determined by the juxtaposition of geometric features at many length scales. In the interest of computational efficiency, recognized heterogeneities are simplified, averaged out, or entirely ignored in spite of recent studies that recognize that: (1) Structural and lithologic heterogeneities exist on all scales in rocks. (2) Small heterogeneities influence, and can control the physical and chemical properties of rocks. In this work we propose a physically based approach for the description and treatment of heterogeneities, that highlights the use of laboratory equipment designed to measure the effect on physical properties of fine scale heterogeneities observed in rocks and soils. We then discuss the development of an integration methodology that uses these measurements to develop and upscale flow and transport models. Predictive simulations are 'calibrated' to the measured heterogeneity data, and subsequently upscaled in a way that is consistent with the transport physics and the efficient use of environmental geophysics. This methodology provides a more accurate interpretation and representation of the subsurface for both environmental engineering and remediation. We show through examples, (i) the important influence of even subtle heterogeneity in the interpreting of geophysical data, and (ii) how physically based upscaling can lead to a different and more accurate description of a heterogeneous system, when compared to a more traditional upscaling approach that combines averaging and the application of core-based models. This may be of particular significance in bio-remediation studies where the link between microorganism activity and mesoscale flow through geologic structures, resides in the integration of multiscale processes.
Experimental study on effects of geologic heterogeneity in enhancing dissolution trapping of supercritical CO2
NASA Astrophysics Data System (ADS)
Agartan, Elif; Trevisan, Luca; Cihan, Abdullah; Birkholzer, Jens; Zhou, Quanlin; Illangasekare, Tissa H.
Dissolution trapping is one of the primary mechanisms that enhance the storage security of supercritical carbon dioxide (scCO2) in saline geologic formations. When scCO2 dissolves in formation brine produces an aqueous solution that is denser than formation brine, which leads to convective mixing driven by gravitational instabilities. Convective mixing can enhance the dissolution of CO2 and thus it can contribute to stable trapping of dissolved CO2. However, in the presence of geologic heterogeneities, diffusive mixing may also contribute to dissolution trapping. The effects of heterogeneity on mixing and its contribution to stable trapping are not well understood. The goal of this experimental study is to investigate the effects of geologic heterogeneity on mixing and stable trapping of dissolved CO2. Homogeneous and heterogeneous media experiments were conducted in a two-dimensional test tank with various packing configurations using surrogates for scCO2 (water) and brine (propylene glycol) under ambient pressure and temperature conditions. The results show that the density-driven flow in heterogeneous formations may not always cause significant convective mixing especially in layered systems containing low-permeability zones. In homogeneous formations, density-driven fingering enhances both storage in the deeper parts of the formation and contact between the host rock and dissolved CO2 for the potential mineralization. On the other hand, for layered systems, dissolved CO2 becomes immobilized in low-permeability zones with low-diffusion rates, which reduces the risk of leakage through any fault or fracture. Both cases contribute to the permanence of the dissolved plume in the formation.
Secondary Organic Aerosol Formation by Heterogeneous
Goddard III, William A.
partitioning from gas to particle phase and, hence, increase the organic particulate material (OPM). Aerosol as to the likely aerosol-phase chemical reactions involving ab- sorbed gas-phase organic compounds. ThSecondary Organic Aerosol Formation by Heterogeneous Reactions of Aldehydes and Ketones: A Quantum
Simulation of Seismic Tunnel Detection Experiments in Heterogeneous Geological Media
NASA Astrophysics Data System (ADS)
Sherman, C. S.; Glaser, S. D.; Rector, J.
Detecting covert tunnels and other underground openings is an important yet challenging problem for geophysicists, especially where geological heterogeneity is pronounced. A number of geophysical methods have been employed to solve this problem, each with varying degrees of success. We focus on the near-surface seismic techniques of surface wave backscattering, surface wave attenuation tomography, body wave diffraction imaging, and resonant imaging. We use the elastodynamic wave propagation code E3D to simulate tunnel detection experiments completed at this site for a range of synthetic fractal velocity models. The Black Diamond mine, located near Pittsburg California, is used for the field test of our analysis. Our results show that for the relatively low-frequency surface wave attenuation and backscattering methods, the maximum detectable tunnel depth in a homogenous medium is approximately equal to the wavelength of the probing Rayleigh wave. The higher-frequency body wave diffraction and resonant imaging techniques are able to locate tunnels at greater depths, but require more sophisticated analysis and are prone to greater attenuation losses. As is expected, for large values of heterogeneity amplitude, ?, the percent standard deviation from the mean velocity model, the average observed surface wave attenuation signal decreases and the maximum detectable tunnel depth decreases. However, for moderate values of heterogeneity amplitude (? < 3%), the average surface wave attenuation signal increases and the maximum detectable tunnel depth increases. For the body wave diffraction and resonant imaging experiments, as ? increases the complexity of the observed signal increases, resulting in more difficult processing and interpretation. The additional scattering attenuation tends to degrade the signals significantly due to their reliance on lower amplitude and higher frequency waves.
Heterogeneous persister cells formation in Acinetobacter baumannii.
Barth, Valdir Crist¾vŃo; Rodrigues, Belisa ┴vila; Bonatto, Grasiela Daiane; Gallo, Stephanie Wagner; Pagnussatti, Vany Elisa; Ferreira, Carlos Alexandre Sanchez; de Oliveira, SĒlvia Dias
Bacterial persistence is a feature that allows susceptible bacteria to survive extreme concentrations of antibiotics and it has been verified in a number of species, such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus spp., Mycobacterium spp. However, even though Acinetobacter baumannii is an important nosocomial pathogen, data regarding its persistence phenotype are still lacking. Therefore, the aim of this study was to evaluate the persistence phenotype in A. baumannii strains, as well as its variation among strains after treatment with polymyxin B and tobramycin. Stationary cultures of 37 polymyxin B-susceptible clinical strains of A. baumannii were analyzed for surviving cells after exposure to 15 Ąg/mL of polymyxin B for 6 h, by serial dilutions and colony counting. Among these, the 30 tobramycin-susceptible isolates also underwent tobramycin treatment at a concentration of 160 Ąg/mL and persister cells occurrence was evaluated equally. A high heterogeneity of persister cells formation patterns among isolates was observed. Polymyxin B-treated cultures presented persister cells corresponding from 0.0007% to 10.1% of the initial population and two isolates failed to produce detectable persister cells under this condition. A high variability could also be observed when cells were treated with tobramycin: the persister fraction corresponded to 0.0003%-11.84% of the pre-treatment population. Moreover, no correlation was found between persister subpopulations comparing both antibiotics among isolates, indicating that different mechanisms underlie the internal control of this phenotype. This is the first report of persister cells occurrence in A. baumannii. Our data suggest that distinct factors regulate the tolerance for unrelated antibiotics in this species, contrasting the multi-drug tolerance observed in other species (eg. dormancy-mediated tolerance). Supporting this observation, polymyxin B--an antibiotic that is believed to act on non-dividing cells as well--failed to eradicate persister cells in the majority of the isolates, possibly reflecting a disconnection between persistence and dormancy. PMID:24391945
Are geological media homogeneous or heterogeneous for neutron investigations?
Wo?nicka, U; Drozdowicz, K; Gaba?ska, B; Krynicka, E; Igielski, A
The thermal neutron absorption cross section of a heterogeneous material is lower than that of the corresponding homogeneous one which contains the same components. When rock materials are investigated the sample usually contains grains which create heterogeneity. The heterogeneity effect depends on the mass contribution of highly and low-absorbing centers, on the ratio of their absorption cross sections, and on their sizes. An influence of the granulation of silicon and diabase samples on the absorption cross section measured with Czubek's method has been experimentally investigated. A 20% underestimation of the absorption cross section has been observed for diabase grains of sizes from 6.3 to 12.8 mm. PMID:12485675
Applying Seismic Methods to National Security Problems: Matched Field Processing With Geological Heterogeneity
S Myers; S Larsen; J Wagoner; B Henderer; D McCallen; J Trebes; P Harben; D Harris
Seismic imaging and tracking methods have intelligence and monitoring applications. Current systems, however, do not adequately calibrate or model the unknown geological heterogeneity. Current systems are also not designed for rapid data acquisition and analysis in the field. This project seeks to build the core technological capabilities coupled with innovative deployment, processing, and analysis methodologies to allow seismic methods to
The Suitable Geological Formations for Spent Fuel Disposal in Romania
Marunteanu, C. [Bucharest Univ. (Romania); Ionita, G. [ANDRAD, Bucharest (Romania); Durdun, I. [S.C. GEOTEC S.A., Bucharest (Romania)
Using the experience in the field of advanced countries and formerly Romanian program data, ANDRAD, the agency responsible for the disposal of radioactive wastes, started the program for spent fuel disposal in deep geological formations with a documentary analysis at the national scale. The potential geological formations properly characterized elsewhere in the world: salt, clay, volcanic tuff, granite and crystalline rocks,. are all present in Romania. Using general or specific selection criteria, we presently consider the following two areas for candidate geological formations: 1. Clay formations in two areas in the western part of Romania: (1) The Pannonian basin Socodor - Zarand, where the clay formation is 3000 m thick, with many bentonitic strata and undisturbed structure, and (2) The Eocene Red Clay on the Somes River, extending 1200 m below the surface. They both need a large investigation program in order to establish and select the required homogeneous, dry and undisturbed zones at a suitable depth. 2. Old platform green schist formations, low metamorphosed, quartz and feldspar rich rocks, in the Central Dobrogea structural unit, not far from Cernavoda NPP (30 km average distance), 3000 m thick and including many homogeneous, fine granular, undisturbed, up to 300 m thick layers. (authors)
Stochastic Modeling of Macrodispersion in Variably Saturated, Spatially Heterogeneous Formations
NASA Astrophysics Data System (ADS)
Russo, David
The macrodispersion tensor, D, plays an important role in solute transport on the field scale. A key problem is how to relate D to the properties of the spatially heterogeneous formation. Under unsaturated flow conditions, the problem is further complicated inasmuch as the relevant flow parameters, the hydraulic conductivity and the water capacity, which depend on the formation properties, depend also on flow-controlled attributes in a highly nonlinear fashion. Consequently, under variably saturated conditions, quantification of D requires several simplifying assumptions regarding the constitutive relationships for unsaturated flow, the flow regime, and the spatial structure of the formation heterogeneity. The present talk focuses on the quantification of D in a variably saturated, spatially heterogeneous formation, accomplished by using a two-stage approach. The approach combines a stochastic, continuum description of a steady-state unsaturated flow, based on small-perturbation, first-order approximation of Darcy's law and the continuity equation for unsaturated flow, with a general Lagrangian description of the motion of an indivisible particle of a passive solute that is carried by the steady-state flow. The resultant, time-dependent D depends on the covariances of the water saturation and the components of the water flux vector, and their cross-covariances, which, in turn, depend on the (cross-)covariances of the relevant formation properties and the pressure head. The effect of few characteristics of the spatially heterogeneous, variably saturated flow system, on D is analyzed and discussed. Main findings reveal that under variably saturated flow conditions, the travel distance required for the principal components of D to approach their asymptotic values may be exceedingly large, particularly in relatively wet formations with significant stratification and with coarse-textured soil material associated with small capillary forces. Hence, in many practical situations of vadose-zone transport, the typical travel distance, may be small compared with the travel distance required for D to reach its asymptotic, Fickian behavior.
Geological pattern formation by growth and dissolution in aqueous systems
Paul Meakin
Although many geological processes take place on time scales that are very long compared with the human experience, essentially all geological processes, fast or slow, are far from equilibrium processes. Surprisingly often, geological processes lead to the formation of quite simple and distinctive patterns, which hint at an underlying simplicity in many complex geological systems.. The ability to predict the seasons was critically important to early human society, and HalleyÆs prediction of the return of the comet that bears his name is still considered to be a scientific milestone. Spatial patterns have also attracted attention because of their aesthetic appeal, which depends in subtle ways on a combination of regularity and irregularity. In recent decades, rapid growth in the capabilities of digital computers has facilitated the simulation of pattern formation processes, and computer simulations have become an important tool for evaluating theoretical concepts and for scientific discovery. Computer technology in combination with other technologies such as high resolution digital cameras, scanning microprobes (atomic force microscopy AFM), confocal microscopy, and scanning tunneling microscopy (STM), for example) has facilitated the quantitative characterization of patterns over a wide range of scales and has enabled rapid advances in our ability to understand the links between large scale pattern formation and microscopic processes. The ability to quantitatively characterize patterns is important because it enables a more rigorous comparison between the predictions of computer models and real world patterns and their formation.In some cases, the idea that patterns with a high degree of regularity have simple origins appears to be justified, but in other cases, such as the formation of almost perfectly circular stone rings due to freeze-thaw cycles simple patterns appear to be the consequence of quite complex processes. In other cases, it has been shown that very simple non-linear processes can lead to extremely complicated patterns, and that some apparently complex disordered systems can be described quantitatively in terms of simple fractal models.
Applying Seismic Methods to National Security Problems: Matched Field Processing With Geological Heterogeneity
Myers, S; Larsen, S; Wagoner, J; Henderer, B; McCallen, D; Trebes, J; Harben, P; Harris, D
Seismic imaging and tracking methods have intelligence and monitoring applications. Current systems, however, do not adequately calibrate or model the unknown geological heterogeneity. Current systems are also not designed for rapid data acquisition and analysis in the field. This project seeks to build the core technological capabilities coupled with innovative deployment, processing, and analysis methodologies to allow seismic methods to be effectively utilized in the applications of seismic imaging and vehicle tracking where rapid (minutes to hours) and real-time analysis is required. The goal of this project is to build capabilities in acquisition system design, utilization of full three-dimensional (3D) finite difference modeling, as well as statistical characterization of geological heterogeneity. Such capabilities coupled with a rapid field analysis methodology based on matched field processing are applied to problems associated with surveillance, battlefield management, finding hard and deeply buried targets, and portal monitoring. This project, in support of LLNL's national-security mission, benefits the U.S. military and intelligence community. Fiscal year (FY) 2003 was the final year of this project. In the 2.5 years this project has been active, numerous and varied developments and milestones have been accomplished. A wireless communication module for seismic data was developed to facilitate rapid seismic data acquisition and analysis. The E3D code was enhanced to include topographic effects. Codes were developed to implement the Karhunen-Loeve (K-L) statistical methodology for generating geological heterogeneity that can be utilized in E3D modeling. The matched field processing methodology applied to vehicle tracking and based on a field calibration to characterize geological heterogeneity was tested and successfully demonstrated in a tank tracking experiment at the Nevada Test Site. A three-seismic-array vehicle tracking testbed was installed on site at LLNL for testing real-time seismic tracking methods. A field experiment was conducted over a tunnel at the Nevada Site that quantified the tunnel reflection signal and, coupled with modeling, identified key needs and requirements in experimental layout of sensors. A large field experiment was conducted at the Lake Lynn Laboratory, a mine safety research facility in Pennsylvania, over a tunnel complex in realistic, difficult conditions. This experiment gathered the necessary data for a full 3D attempt to apply the methodology. The experiment also collected data to analyze the capabilities to detect and locate in-tunnel explosions for mine safety and other applications. In FY03 specifically, a large and complex simulation experiment was conducted that tested the full modeling-based approach to geological characterization using E2D, the K-L statistical methodology, and matched field processing applied to tunnel detection with surface seismic sensors. The simulation validated the full methodology and the need for geological heterogeneity to be accounted for in the overall approach. The Lake Lynn site area was geologically modeled using the code Earthvision to produce a 32 million node 3D model grid for E3D. Model linking issues were resolved and a number of full 3D model runs were accomplished using shot locations that matched the data. E3D-generated wavefield movies showed the reflection signal would be too small to be observed in the data due to trapped and attenuated energy in the weathered layer. An analysis of the few sensors coupled to bedrock did not improve the reflection signal strength sufficiently because the shots, though buried, were within the surface layer and hence attenuated. Ability to model a complex 3D geological structure and calculate synthetic seismograms that are in good agreement with actual data (especially for surface waves and below the complex weathered layer) was demonstrated. We conclude that E3D is a powerful tool for assessing the conditions under which a tunnel could be detected in a specific geological setting. Finally, the Lak
Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site
Lin, Xueju; Kennedy, David W.; Fredrickson, Jim K.; Bjornstad, Bruce N.; Konopka, Allan
The microbial diversity in subsurface sediments at the Hanford Site's 300 Area in southeastern Washington State was investigated by analyzing 21 samples recovered from depths that ranged from 9 to 52 m. Approximately 8000 non-chimeric Bacterial and Archaeal 16S rRNA gene sequences were analyzed across geological strata that contain a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (Operational Taxonomic Units, defined at the 97% identity level). Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (based upon Chao1 estimator) was highest (>700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic transition zone, richness was about 325 and declined to less than 50 in the deeper reduced zones. The Bacterial community in the oxic Hanford and Ringold Formations contained members of 9 major well-recognized phyla as well 30 as unusually high proportions of 3 candidate divisions (GAL15, NC10, and SPAM). The deeper Ringold strata were characterized by low OTU richness and a very high preponderance (ca. 90%) of Proteobacteria. The study has greatly expanded the intralineage phylogenetic diversity within some major divisions. These subsurface sediments have been shown to contain a large number of phylogenetically novel microbes, with substantial heterogeneities between sediment samples from the same geological formation.
A Fundamental Study of Convective Mixing Contributing to Dissolution Trapping of CO2 in Heterogeneous Geologic Media using Surrogate Fluids and Numerical Modeling
NASA Astrophysics Data System (ADS)
Illangasekare, Tissa; Agartan, Eliff; Trevisan, Luca; Cihan, Abdullah; Birkholzer, Jens; Zhou, Quanlin
Geologic sequestration of carbon dioxide is considered as an important strategy to slow down global warming and hence climate change. Dissolution trapping is one of the primary mechanisms contributing to long-term storage of supercritical CO2 (scCO2) in deep saline geologic formations. When liquid scCO2 is injected into the formation, its density is less than density of brine. During the movement of injected scCO2 under the effect of buoyancy forces, it is immobilized due to capillary forces. With the progress of time, entrapped scCO2 dissolves in formation brine, and density-driven convective fingers are expected to be generated due to the higher density of the solute compared to brine. These fingers enhance mixing of dissolved CO2 in brine. The development and role of these convective fingers in mixing in homogeneous formations have been studied in past investigations. The goal of this study is to evaluate the contribution of convective mixing to dissolution trapping of scCO2 in naturally heterogeneous geologic formations via laboratory experiments and numerical analyses. To mimic the dissolution of scCO2 in formation brine under ambient laboratory conditions, a group of surrogate fluids were selected according to their density and viscosity ratios, and tested in different fluid/fluid mixtures and variety of porous media test systems. After selection of the appropriate fluid mixture, a set of experiments in a small test tank packed in homogeneous configurations was performed in order to analyze the fingering behavior. A second set of experiments was conducted for layered systems to study the effects of formation heterogeneity on convective mixing. To capture the dominant processes observed in the experiments, a Finite Volume based numerical code was developed. The model was then used to simulate more complex heterogeneous systems that were not represented in the experiments. Results of these analyses suggest that density-driven convective fingers that contributes to mixing in homogeneous formations may not be significantly contributing to mixing and hence dissolution trapping in heterogeneous formations. However, further experimental and modeling investigations are needed to investigate how the geologic architecture that defines the spatial distribution of low permeability zones contributes to overall dissolution trapping.
Flow in fractured geological media: the influence of fracture scale heterogeneity
NASA Astrophysics Data System (ADS)
Meheust, Y.; De Dreuzy, J.; Pichot, G.
Flow channeling and permeability scaling in fractured geological media are usually adressed either at the fracture- or at the network- scales. In the latter case they are linked to the topological structure of the network, while at the fracture scale they are controlled by the variability of the local aperture distribution inside individual fractures. We combine these two effects and investigate how flow localization below the scale of individual fractures impacts that at the network scale and the resulting medium permeability. This is addressed with a highly-resolved 3D discrete fracture network model that accounts both for the typical topology of geological fracture networks and for the spatially-correlated roughness of fracture walls. At the fracture scale, accounting for aperture heterogeneities leads to a reduction of the equivalent fracture transmissivity of up to a factor of 6 as compared to the parallel plate of identical mean aperture, depending on the fractures' closure. At the network scale significant coupling is observed in most cases between flow heterogeneities at the fracture scale and those observed for the complete network, provided that the size of the medium be less than 20 times larger than the typical correlation length between the two matching walls of an individual fracture [1]. One single scalar parameter accounts for the deviation of the medium permeability from that of a network of identical topology and consisting of parallel plate fractures of mean apertures identical to those of the heterogeneous fractures in our medium. [1] de Dreuzy, J.-R., Mķheust, Y. and Pichot, G. (2012), Influence of fracture scale heterogeneity on the flow properties of three-dimensional Discrete Fracture Networks (DFN), J. Geophys. Res.-Earth Surf. 117(B11207), 21 pp. Local fluid fluxes inside a discrete fracture network consisting of fractures with spatially-varying apertures.
Dispersion measurement as a method of quantifying geologic characterization and defining reservoir heterogeneity. Final report
Menzie, D.E.
The main objective of this research project is to investigate dispersion as a method of quantifying geological characterization and defining reservoir heterogeneity in order to enhance crude oil recovery. The dispersion of flow of a reservoir rock (dispersion coefficient and dispersivity) was identified as one of the physical properties of a reservoir rock by measuring the mixing of two miscible fluids, one displacing the other in a porous medium. A rock was 100% saturated with a resident fluid and displaced by a miscible fluid of equal viscosity and equal density. Some specific experiments were performed with unequal densities. Produced fluid was analyzed by refractometer, nuclear reaction, electrical conductivity and X-ray scan. Several physical and flow characteristics were measured on the sand rock sample in order to establish correlations with the measured dispersion property. Absolute permeability, effective porosity, relative permeability, capillary pressure, the heterogeneity factor and electrical conductivity were used to better understand the flow system. Linear, transverse, 2-D and 3-D dispersions were measured and used to characterize the rock heterogeneity of the flow system. A new system of measuring dispersion was developed using a gas displacing gas system in a porous medium. An attempt was also made to determine the dispersion property of an actual reservoir from present day well log data on a producing well. 275 refs., 102 figs., 17 tabs.
Acid-catalyzed Heterogeneous Reactions in SOA Formation
NASA Astrophysics Data System (ADS)
Ng, N.; Keywood, M.; Varutbangkul, V.; Gao, S.; Loewer, E.; Surratt, J.; Richard, F. C.; John, S. H.
The importance of heterogeneous reactions in secondary organic aerosol (SOA) formation has recently excited a great deal of interest in the aerosol community. Jang and Kamens (2001) showed enhanced aerosol yield from aldehydes, which can be produced by atmospheric photochemical reactions, in the presence of acidic seed. They suggest that the carbonyl functional groups of the aldehydes further react in the aerosol phase via hydration, polymerization, and hemiacetal/acetal formation with alcohols at an accelerated rate in the presence of acid. Jang et al. (2003) demonstrated similar results using a flow reactor and Czoschke et al. (in press) qualitatively showed increased yields for isoprene and alpha-pinene ozonolysis in the presence of acidic seed. While these findings are intriguing and important, the conditions under which the experiments were carried out were atmospherically unrealistic. A series of SOA formation experiments have been carried out in the Caltech Indoor Chamber Facility, which is comprised of dual 28 m3 FEP Teflon chambers, with the flexibility to carry out both dark ozonolysis and photochemical OH oxidation reactions. Cycloheptene and alpha-pinene were oxidized in the presence of neutral seed under dry (<10% RH) and humid (50% RH) conditions and in the presence of acidic seed under humid (50% RH) conditions. The SOA yields for these experiments will be presented, and the extent of the influence of acid-catalyzed reactions on SOA yield will be discussed. Reference List 1. Cocker, D. R. III. and R. C. Flagan and J. H. Seinfeld, State-of-the-art chamber facility for studying atmospheric aerosol chemistry, Environmental Science and Technology, 35, 2594-2601, 2001. 2. Czoschke, N. M., M. Jang, and R. M. Kamens, Effect of acid seed on biogenic sceondary organic aerosol growth, Atmospheric Environment, In press. 3. Jang, M., S. Lee, and R. M. Kamens, Organic aerosol growth by acid-catalyzed heterogeneous reactions of octanal in a flow reactor, Atmospheric Environment, 37, 2125-2138, 2003. 4. Jang, M. S. and R. M Kamens, Atmospheric secondary aerosol formation by heterogeneous reactions of aldehydes in the presence of a sulfuric acid aerosol catalyst. Environmental Science and Technology, 35, 4758-4766,2001.
Geologically based model of heterogeneous hydraulic conductivity in an alluvial setting
NASA Astrophysics Data System (ADS)
Fogg, Graham E.; Noyes, Charles D.; Carle, Steven F.
Information on sediment texture and spatial continuity are inherent to sedimentary depositional facies descriptions, which are therefore potentially good predictors of spatially varying hydraulic conductivity (K). Analysis of complex alluvial heterogeneity in Livermore Valley, California, USA, using relatively abundant core descriptions and field pumping-test data, demonstrates a depositional-facies approach to characterization of subsurface heterogeneity. Conventional textural classifications of the core show a poor correlation with K; however, further refinement of the textural classifications into channel, levee, debris-flow, and flood-plain depositional facies reveals a systematic framework for spatial modeling of K. This geologic framework shows that most of the system is composed of very low-K flood-plain materials, and that the K measurements predominantly represent the other, higher-K facies. Joint interpretation of both the K and geologic data shows that spatial distribution of K in this system could not be adequately modeled without geologic data and analysis. Furthermore, it appears that K should not be assumed to be log-normally distributed, except perhaps within each facies. Markov chain modeling of transition probability, representing spatial correlation within and among the facies, captures the relevant geologic features while highlighting a new approach for statistical characterization of hydrofacies spatial variability. The presence of fining-upward facies sequences, cross correlation between facies, as well as other geologic attributes captured by the Markov chains provoke questions about the suitability of conventional geostatistical approaches based on variograms or covariances for modeling geologic heterogeneity. Rķsumķ Les informations sur la texture des sķdiments et leur continuitķ spatiale font partie des descriptions de faciĶs sķdimentaires de dķp¶t. Par consķquent, ces descriptions sont d'excellents prķdicteurs potentiels des variations spatiales de la conductivitķ hydraulique (K). L'analyse de l'hķtķrogķnķitķ des alluvions complexes de la vallķe de Livermore (Californie, ╔tats-Unis), sur la base de descriptions de carottes relativement nombreuses et de donnķes d'essais de pompage, montre que l'hķtķrogķnķitķ souterraine peut Ļtre caractķrisķe par une approche des faciĶs de dķp¶t. Des classifications conventionnelles de la texture de la carotte montrent une corrķlation mķdiocre avec K; toutefois, une amķlioration ultķrieure des classifications de texture en faciĶs de dķp¶t de chenal, de levķe d'inondation, de coulķe boueuse et de plaine d'inondation a fourni un cadre systķmatique pour une modķlisation spatiale de K. Ce cadre gķologique montre que le systĶme est composķ pour l'essentiel par des matķriaux d'inondation Ó trĶs faible permķabilitķ ceci laisse envisager qu'on ne peut pas supposer que K suit une distribution log-normal, sauf peut-Ļtre Ó l'intķrieur de chaque faciĶs. Une modķlisation par chaŅne de Markov de la probabilitķ de passage, reprķsentant la corrķlation spatiale dans les faciĶs et entre eux, prend en compte les faits gķologiques intķressants tout en fournissant une approche nouvelle pour une caractķrisation statistique de la variabilitķ spatiale des faciĶs. La prķsence de sķquences Ó faciĶs tronquķs vers le haut, d'une corrķlation croisķe entre faciĶs, ainsi que d'autres caractĶres gķologiques pris en compte par les chaŅnes de Markov conduisent Ó se poser des questions sur l'adķquation des approches gķostatistiques conventionnelles utilisant les variogrammes ou les covariances pour modķliser l'hķtķrogķnķitķ gķologique. Resumen La informaci¾n respecto a la textura de los sedimentos y la continuidad espacial es inherente a las descripciones de las facies deposicionales sedimentarias. De este modo, estas descripciones se convierten en excelentes predictores potenciales de las variaciones espaciales de la conductividad hidrßulica (K). El anßlisis de la heterogeneidad en un aluvial en el Valle de L
Determining resistivity of a geological formation using circuitry located within a borehole casing
Vail III, William Banning
Geological formation resistivity is determined. Circuitry is located within the borehole casing that is adjacent to the geological formation. The circuitry can measure one or more voltages across two or more voltage measurement electrodes associated with the borehole casing. The measured voltages are used by a processor to determine the resistivity of the geological formation. A common mode signal can also be reduced using the circuitry.
Elastic and plastic effects on heterogeneous nucleation and nanowire formation
NASA Astrophysics Data System (ADS)
Boussinot, G.; Schulz, R.; H³ter, C.; Brener, E. A.; Spatschek, R.
We investigate theoretically the effects of elastic and plastic deformations on heterogeneous nucleation and nanowire formation. In the first case, the influence of the confinement of the critical nucleus between two parallel misfitting substrates is investigated using scaling arguments. We present phase diagrams giving the nature of the nucleation regime as a function of the driving force and the degree of confinement. We complement this analytical study by amplitude equations simulations. In the second case, the influence of a screw dislocation inside a nanowire on the development of the morphological surface instability of the wire, related to the Rayleigh-Plateau instability, is examined. Here the screw dislocation provokes a torsion of the wire known as Eshelby twist. Numerical calculations using the finite element method and the amplitude equations are performed to support analytical investigations. It is shown that the screw dislocation promotes the Rayleigh-Plateau instability.
Influence of tile-drainage on groundwater flow and nitrate transport in heterogeneous geological materials
NASA Astrophysics Data System (ADS)
De Schepper, G.; Therrien, R.; Refsgaard, J.
Subsurface drainage is a common agricultural practice in poorly drained production fields to guarantee the productivity of crops and to reduce flooding risks. The impact of shallow tile-drainage networks on groundwater flow patterns and associated nitrate transport from the surface needs to be quantified for adequate agricultural management. A challenge is to represent tile-drain networks in numerical models, at the field scale, while accounting for the influence of subsurface heterogeneities on flow and transport. A numerical model of a tile-drainage system has been developed with the fully integrated HydroGeoSphere model for the Lillebaek agricultural catchment, Denmark. The Lillebaek catchment is an experimental study area where hydraulic heads, stream and drain discharges, as well as groundwater and surface water nitrate concentrations are regularly measured. This catchment includes various tile-drainage networks that are monitored on a daily basis; the one we have been focusing on is about 5 ha within a 34 ha model domain. The Lillebaek catchment subsurface is made of about 30 m thick Quaternary deposits which consist of a local sandy aquifer with upper and lower clayey till units, confining the aquifer in the upper part. The main modelling objective is to assess the influence of tile drains on the water flow pattern within the confining clayey till unit with and on the nitrate reduction zone depth, also known as the redox-interface, while accounting for local geological heterogeneities. Using the national-scale geological model for Denmark combined with available local data, a hydrogeological model at field scale has been generated. A proper representation of the tile-drains geometry is essential to calibrate and validate the water flow model associated with nitrate transport. HydroGeoSphere can represent drains directly into a model as one-dimensional features, which however requires a very fine mesh discretization that limits the size of the simulation domain. Because of this limitation, we are testing an alternate approach where the tile-drain network and surrounding porous medium are represented by a dual-continuum formulation, similar to that used to represent fractured porous media, for example. Equivalent properties for the tile-drain network are defined from their geometry and spacing and the dual formulation allows for water and solute exchange between the drains and surrounding soil matrix. Validating this drain representation method in a model should allow us to work at larger scale in the future and thus to model tile-drained catchments without having to implement each and every drain, which would induce a very high number of model elements leading to time-consuming simulations. This contribution will focus on some preliminary simulations designed to validate the dual-continuum approach to represent tile-drained networks. These simulations are also designed to demonstrate the applicability of the approach for 3D variably-saturated flow and transport modelling at the field scale, accounting for local geological heterogeneities.
A Formative Assessment of Geologic Time for High School Earth Science Students
NSDL National Science Digital Library
Earth science courses typically include the concept of geological time. The authors of this study attempt to move past traditional assessment practices and develop a formative assessment of students' understanding of the construction of the geologic time scale and how it is interpreted. Through this approach students are challenged to conceptualize the geologic time scale by comparing it to a student-produced time scale for an older adult's life. This formative assessment allows the teacher to alter instruction based on students' feedback in order to maximize student understanding of geologic time.
Reidel, Stephen P.
This chapter summarizes the geology of the single-shell tank (SST) farms in the context of the regionÆs geologic history. This chapter is based on the information in the geology data package for the SST waste management areas and SST RFI Appendix E, which builds upon previous reports on the tank farm geology and Integrated Disposal Facility geology with information available after those reports were published.
The geologic mapping of Venus using C-1 format: Sheets 75N254, 60N263
NASA Technical Reports Server (NTRS)
Shalimov, I. V.
The results of geologic mapping of Venus, produced on the base of Magellan images, are presented. We submit two C-1 format geologic maps with the appropriate legend. The mapping territory was taken from Venera 15 and 16 missions and geologic maps were composed. Magellan images allow us to divide some types of the plains units to determine the lava flow direction and to map with better accuracy.
Evaluating variable switching and flash methods in modeling carbon sequestration in deep geologic formations
Mills, Richard
Evaluating variable switching and flash methods in modeling carbon sequestration in deep geologic performance computing to assess the risks involved in carbon sequestration in deep geologic formations-thermal- chemical processes in variably saturated, non-isothermal porous media is applied to sequestration
Quantification of rock heterogeneities by structural geological field studies combined with laboratory analyses
NASA Astrophysics Data System (ADS)
Reyer, Dorothea; Afsar, Filiz; Philipp, Sonja
Heterogeneous rock properties in terms of layering and complex infrastructure of fault zones are typical in sedimentary successions. The knowledge of in-situ mechanical rock properties is crucial for a better understanding of processes such as fracturing and fluid transport in fractured reservoirs. To estimate in situ rock properties at different depths it is important to understand how rocks from outcrops differ from rocks at depth, for example due to alteration and removal of the overburden load. We aim at quantifying these properties by performing structural geological field studies in outcrop analogues combined with laboratory analyses of outcrop samples and drill-cores. The field studies focus on 1) fault zone infrastructure and 2) host rock fracture systems in two different study areas with different lithologies, the North German and the Bristol Channel Basin. We analyse quantitatively the dimension, geometry, persistence and connectivity of fracture systems. The field studies are complemented by systematic sampling to obtain the parameters Young's modulus, compressive and tensile strengths and elastic strain energy (also referred to as destruction work) from which we estimate rock and fracture toughnesses. The results show that in rocks with distinctive layering fractures are often restricted to individual layers, that is, stratabound. The probability of arrest seems to depend on the stiffness contrast between two single layers as well as on the thickness of the softer layer. The results also show that there are clear differences between fault zones in the different lithologies in terms of damage zone thicknesses and fracture system parameters. The results of laboratory analyses show that the mechanical properties vary considerably and for many samples there are clear directional differences. That is, samples taken perpendicular to layering commonly have higher stiffnesses and strengths than those taken parallel to layering. We combine the results of laboratory analyses and field measurements to specify the mechanical heterogeneities of typical sedimentary rocks and of the mechanical units of fault zones. The results from drill-core sample analyses are then compared with the results from the outcrop samples. Another approach is to analyse how rock mechanical properties correlate with petrographic properties (e.g., mineral content, cementation, fabric) to use this knowledge to extrapolate the data to depth. Acknowledgements The authors appreciate the support of 'Niedersõchsisches Ministerium f³r Wissenschaft und Kultur' and 'Baker Hughes' within the gebo research project (http://www.gebo-nds.de). The project "Fracture propagation and reservoir permeability in limestone-marl alternations" is funded by the Deutsche Forschungsgemeinschaft (German Research Foundation, http://www.dfg.de).
Episodic and long-lived river incision along geologically heterogeneous passive margins
NASA Astrophysics Data System (ADS)
Harbor, D. J.; Gunnell, Y.; Hancock, G. S.
Hillslopes and river profiles in the southern and central Appalachians and the Eastern Ghats of India do not display the characteristics of dynamic equilibrium expected for Mesozoic passive margins. Escarpments, gorges, and river knickpoints characterize many portions of the margin highlands and continental interior. Bedrock resistance is a first-order control on topography, but it is significantly altered by the history of erosion. A conceptual model of episodic drainage rearrangement and subsequent incision in these spatially varied geologic settings underscores the potential erosional heterogeneity of these long-eroding margins. Waves of heightened river incision extend deep into the margin, yielding steep topography on comparatively weak bedrock, and regional escarpments and plateau remnants that cross lithologic boundaries. Correlating major incision events through the landscape is possible using basin-wide analysis of river profile shape, but it is complicated by many factors including 1) the effects of rock resistance on rate and style of incision, 2) river dynamics that depend on sediment load, and 3) meander bend cutoffs. Knickpoint migration rates determined from terrace ages, in-channel erosion rate, and basin-wide correlations suggest that incision migrates upriver over millions of years. Renewed Quaternary incision by the James River, which has a large drainage basin likely captured during the Neogene, occurs by further knickpoint retreat that could be a response to erosional unloading and uplift, or simply to climate change. In one Appalachian drainage basin, modern channel morphology plus integration of erosion over the long term suggests that episodic, nonuniform erosion accounts for the majority of late Quaternary incision.
Nitrate reduction in geologically heterogeneous catchments--a framework for assessing the scale of predictive capability of hydrological models.
Refsgaard, Jens Christian; Auken, Esben; Bamberg, Charlotte A; Christensen, Britt S B; Clausen, Thomas; Dalgaard, Esben; Effers°, Flemming; Ernstsen, Vibeke; Gertz, Flemming; Hansen, Anne Lausten; He, Xin; Jacobsen, Brian H; Jensen, Karsten H°gh; J°rgensen, Flemming; J°rgensen, Lisbeth Flindt; Koch, Julian; Nilsson, Bertel; Petersen, Christian; De Schepper, Guillaume; Schamper, Cyril; S°rensen, Kurt I; Therrien, Rene; Thirup, Christian; Viezzoli, Andrea
In order to fulfil the requirements of the EU Water Framework Directive nitrate load from agricultural areas to surface water in Denmark needs to be reduced by about 40%. The regulations imposed until now have been uniform, i.e. the same restrictions for all areas independent of the subsurface conditions. Studies have shown that on a national basis about 2/3 of the nitrate leaching from the root zone is reduced naturally, through denitrification, in the subsurface before reaching the streams. Therefore, it is more cost-effective to identify robust areas, where nitrate leaching through the root zone is reduced in the saturated zone before reaching the streams, and vulnerable areas, where no subsurface reduction takes place, and then only impose regulations/restrictions on the vulnerable areas. Distributed hydrological models can make predictions at grid scale, i.e. at much smaller scale than the entire catchment. However, as distributed models often do not include local scale hydrogeological heterogeneities, they are typically not able to make accurate predictions at scales smaller than they are calibrated. We present a framework for assessing nitrate reduction in the subsurface and for assessing at which spatial scales modelling tools have predictive capabilities. A new instrument has been developed for airborne geophysical measurements, Mini-SkyTEM, dedicated to identifying geological structures and heterogeneities with horizontal and lateral resolutions of 30-50 m and 2m, respectively, in the upper 30 m. The geological heterogeneity and uncertainty are further analysed by use of the geostatistical software TProGS by generating stochastic geological realisations that are soft conditioned against the geophysical data. Finally, the flow paths within the catchment are simulated by use of the MIKE SHE hydrological modelling system for each of the geological models generated by TProGS and the prediction uncertainty is characterised by the variance between the predictions of the different models. PMID:23953482
The Effects of Realistic Geological Heterogeneity on Seismic Modeling: Applications in Shear Wave Generation and Near-Surface Tunnel Detection
NASA Astrophysics Data System (ADS)
Sherman, Christopher Scott
Naturally occurring geologic heterogeneity is an important, but often overlooked, aspect of seismic wave propagation. This dissertation presents a strategy for modeling the effects of heterogeneity using a combination of geostatistics and Finite Difference simulation. In the first chapter, I discuss my motivations for studying geologic heterogeneity and seis- mic wave propagation. Models based upon fractal statistics are powerful tools in geophysics for modeling heterogeneity. The important features of these fractal models are illustrated using borehole log data from an oil well and geomorphological observations from a site in Death Valley, California. A large part of the computational work presented in this disserta- tion was completed using the Finite Difference Code E3D. I discuss the Python-based user interface for E3D and the computational strategies for working with heterogeneous models developed over the course of this research. The second chapter explores a phenomenon observed for wave propagation in heteroge- neous media - the generation of unexpected shear wave phases in the near-source region. In spite of their popularity amongst seismic researchers, approximate methods for modeling wave propagation in these media, such as the Born and Rytov methods or Radiative Trans- fer Theory, are incapable of explaining these shear waves. This is primarily due to these method's assumptions regarding the coupling of near-source terms with the heterogeneities and mode conversion. To determine the source of these shear waves, I generate a suite of 3D synthetic heterogeneous fractal geologic models and use E3D to simulate the wave propaga- tion for a vertical point force on the surface of the models. I also present a methodology for calculating the effective source radiation patterns from the models. The numerical results show that, due to a combination of mode conversion and coupling with near-source hetero- geneity, shear wave energy on the order of 10% of the compressional wave energy may be generated within the shear radiation node of the source. Interestingly, in some cases this shear wave may arise as a coherent pulse, which may be used to improve seismic imaging efforts. In the third and fourth chapters, I discuss the results of a numerical analysis and field study of seismic near-surface tunnel detection methods. Detecting unknown tunnels and voids, such as old mine workings or solution cavities in karst terrain, is a challenging prob- lem in geophysics and has implications for geotechnical design, public safety, and domestic security. Over the years, a number of different geophysical methods have been developed to locate these objects (microgravity, resistivity, seismic diffraction, etc.), each with varying results. One of the major challenges facing these methods is understanding the influence of geologic heterogeneity on their results, which makes this problem a natural extension of the modeling work discussed in previous chapters. In the third chapter, I present the results of a numerical study of surface-wave based tunnel detection methods. The results of this analysis show that these methods are capable of detecting a void buried within one wavelength of the surface, with size potentially much less than one wavelength. In addition, seismic surface- wave based detection methods are effective in media with moderate heterogeneity (epsilon < 5 %), and in fact, this heterogeneity may serve to increase the resolution of these methods. In the fourth chapter, I discuss the results of a field study of tunnel detection methods at a site within the Black Diamond Mines Regional Preserve, near Antioch California. I use a com- bination of surface wave backscattering, 1D surface wave attenuation, and 2D attenuation tomography to locate and determine the condition of two tunnels at this site. These results compliment the numerical study in chapter 3 and highlight their usefulness for detecting tunnels at other sites.
Modeling CO2 distribution in a heterogeneous sandstone reservoir: the Johansen Formation, northern North Sea
NASA Astrophysics Data System (ADS)
Sundal, Anja; Miri, Rohaldin; Petter Nystuen, Johan; Dypvik, Henning; Aagaard, Per
The last few years there has been broad attention towards finding permanent storage options for CO2. The Norwegian continental margin holds great potential for storage in saline aquifers. Common for many of these reservoir candidates, however, is that geological data are sparse relative to thoroughly mapped hydrocarbon reservoirs in the region. Scenario modeling provides a method for estimating reservoir performances for potential CO2 storage sites and for testing injection strategies. This approach is particularly useful in the evaluation of uncertainties related to reservoir properties and geometry. In this study we have tested the effect of geological heterogeneities in the Johansen Formation, which is a laterally extensive sandstone and saline aquifer at burial depths of 2 - 4 km, proposed as a suitable candidate for CO2 storage by Norwegian authorities. The central parts of the Johansen Formation are underlying the operating hydrocarbon field Troll. In order not to interfere with ongoing gas production, a potential CO2 injection well should be located at a safe distance from the gas reservoir, which consequently implies areas presently without well control. From 3D seismic data, prediction of spatial extent of sandstone is possible to a certain degree, whereas intra-reservoir flow baffles such as draping mudstone beds and calcite cemented layers are below seismic resolution. The number and lateral extent of flow baffles, as well as porosity- and permeability distributions are dependent of sedimentary facies and diagenesis. The interpretation of depositional environment and burial history is thus of crucial importance. A suite of scenario models was established for a potential injection area south of the Troll field. The model grids where made in Petrel based on our interpretations of seismic data, wire line logs, core and cuttings samples. Using Eclipse 300 the distribution of CO2 is modeled for different geological settings; with and without the presence of pervasive low permeability draping mudstone layers, and with varying lateral extent of potential calcite cemented layers in 8 to 15 intra-reservoir depth levels. The modeled area covers 10 x 15.8 km, with a thickness of 110 m at the injection point. Simulations were run with an injection phase of 30 years plus 100 years of migration. The presence of meso-scale flow baffles causes a reduction in vertical permeability in addition to the facies related variation on the micro-scale. Scenarios including potential flow baffles as separate layers in the model grids were compared to scenarios in which the effect of flow baffles were included using harmonic mean average of vertical permeability. The subsequent differences in CO2 distribution are important in estimating the contact area between the plume front and reservoir brine. A heterogeneous reservoir with internal flow baffles is not necessarily a disadvantage as long as sufficient injectivity is maintained within individual sandstone bodies. In each scenario we aim to adapt a suitable injection strategy with respect to utilizing local effects such as the delimitation of gravitational flow, in order to increase reservoir sweep and maximize the effect of trapping mechanisms (i.e. residual, stratigraphic, mineral and dissolution).
Geologic and hydrologic characterization of coalbed methane reservoirs, Fruitland Formation, San Juan basin, Colorado and New Mexico
Ayers, W.B. Jr.; Ambrose, W.A.; Kaiser, W.R.; Laubach, S.E.; Scott, A.R.; Yeh, J.S. (Univ. of Texas, Austin (United States)); Tremain, C.M. (Colorado Geological Survey, Denver (United States)); Whitehead, N.H. III (New Mexico Bureau of Mines and Mineral Resources, Socorro, NM (United States))
Geologic and hydrologic studies clarify coalbed methane reservoir characteristics of the Fruitland Formation. In geologic studies, data from geophysical logs were used to map coal (reservoir) occurrence and structural features; fractures in coal seams were described at outcrops and in cores. In hydrologic studies, Fruitland bottom-home pressures calculated from well head and pressure regime and to estimate vertical and lateral pressure gradients. Chemical facies of produced waters were defined by Piper and Stiff ionic-ratio diagrams. The thickest coal seams trend northwestward and occur in the north-central part of the basin; these seams are the most permeable units in the Fruitland Formation. In the southwest part of the basin, coal seams trend either northwestward or northeastward. Coal trends are predictable and are controlled by depositional setting. Fracture trends in coal seams in the southern two-thirds of the basin are north-northeast, whereas fracture trends in the northern third of the basin and underpressured in much of the rest of the basin. Overpressuring is attributed to artesian conditions. Large vertical and/or lateral pressure gradients indicate reservoir heterogeneity. Low-chloride, high-alkalinity waters coincide with overpressuring, and saline NaCl-type waters coincide with underpressuring. Geologic studies delineated coalbed methane reservoirs (coal seams), whereas hydrologic studies indicated reservoir conditions such as permeability and pressure regime. By integrating geologic and hydrologic findings, the authors divided the San Juan basin into regions having similar reservoir characteristics and defined areas with optimal conditions for coalbed methane production. The approaches used in this study are transferable to other coal basins.
Predicting 87Sr/86Sr in surface water using bedrock geology: Understanding geologic heterogeneity and scale to improve isoscapes and animal migration reconstruction
NASA Astrophysics Data System (ADS)
Hegg, J. C.; Fremier, A. K.; Kennedy, B. P.
Recent advances in reconstructing location and movement patterns using isotopic tracers have revolutionized the study of migration across taxa. Strontium ratio (87Sr/86Sr) in particular has allowed unprecedented temporal and spatial resolution in migration studies. The development of 87Sr/86Sr isoscapes for surface water has been hindered, however, by the difficulty in predicting 87Sr/86Sr variation across the landscape. The abundance of strontium isotopes is tightly linked to the underlying geology; inviting the possibility that 87Sr/86Sr could be predicted directly from bedrock geology. Accurate predictive models would increase spatial resolution in studies of migration, but previous attempts to predict 87Sr/86Sr in stream water have produced limited success and are not easily generalized across the landscape. Using data from the Snake River of Idaho we present a method for accurately predicting stream water 87Sr/86Sr from bedrock. We further show that our predictions can be used to accurately determine the origin of fish based upon the distinct 87Sr/86Sr signatures in their otoliths. We discuss the importance of understanding the affects of geologic heterogeneity and scale for improving our ability to generalize predictions in future models.
2006 Proc. Annu. Conf. SEAFWA Geologic Analyses for EvaluatingWatershed Heterogeneity
Harbor, David
(Micropterus dolomieu) from the Maury and James rivers (Virginia). Cluster analysis of multivariate geologic of otolith chemistry in riverine smallmouth bass (Micropterus dolomieu) populations. Trace element concen
Fundamental Study on the Dynamics of Heterogeneity-Enhanced CO2 Gas Evolution in the Shallow Subsurface During Possible Leakage from Deep Geologic Storage Sites
NASA Astrophysics Data System (ADS)
Plampin, M. R.; Lassen, R. N.; Sakaki, T.; Pawar, R.; Jensen, K.; Illangasekare, T. H.
A concern for geologic carbon sequestration is the potential for CO2 stored in deep geologic formations to leak upward into shallow freshwater aquifers where it can have potentially detrimental impacts to the environment and human health. Understanding the mechanisms of CO2 exsolution, migration and accumulation (collectively referred to as 'gas evolution') in the shallow subsurface is critical to predict and mitigate the environmental impacts. During leakage, CO2 can move either as free-phase or as a dissolved component of formation brine. CO2 dissolved in brine may travel upward into shallow freshwater systems, and the gas may be released from solution. In the shallow aquifer, the exsolved gas may accumulate near interfaces between soil types, and/or create flow paths that allow the gas to escape through the vadose zone to the atmosphere. The process of gas evolution in the shallow subsurface is controlled by various factors, including temperature, dissolved CO2 concentration, water pressure, background water flow rate, and geologic heterogeneity. However, the conditions under which heterogeneity controls gas phase evolution have not yet been precisely defined and can therefore not yet be incorporated into models used for environmental risk assessment. The primary goal of this study is to conduct controlled laboratory experiments to help fill this knowledge gap. With this as a goal, a series of intermediate-scale laboratory experiments were conducted to observe CO2 gas evolution in porous media at multiple scales. Deionized water was saturated with dissolved CO2 gas under a specified pressure (the saturation pressure) before being injected at a constant volumetric flow rate into the bottom of a 1.7 meter-tall by 5.7 centimeter-diameter column or a 2.4 meter-tall by 40 centimeter-wide column that were both filled with sand in various heterogeneous packing configurations. Both test systems were initially saturated with fresh water and instrumented with soil moisture sensors to monitor the evolution of gas phase through time by measuring the average water content in small sampling volumes of soil. Tensiometers allowed for observation of water pressure through space and time in the test systems, and a computer-interfaced electronic scale continuously monitored the outflow of water from the top of the two test columns. Several packing configurations with five different types of sands were used in order to test the effects of various pore size contrasts and interface shapes on the evolution of the gas phase near soil texture transitions in the heterogeneous packings. Results indicate that: (1) heterogeneity affects gas phase evolution patterns within a predictable range of conditions quantified by the newly introduced term 'oversaturation,' (2) soil transition interfaces where less permeable material overlies more permeable material have a much more pronounced effect on gas evolution than interfaces with opposite orientations, and (3) anticlines (or stratigraphic traps) cause significantly greater gas accumulation than horizontal interfaces. Further work is underway to apply these findings to more realistic, two-dimensional scenarios, and to assess how well existing numerical models can capture these processes.
Geology of the Grand Canyon: Interpreting its rock layers and formation
NSDL National Science Digital Library
In this culminating activity, students will be assessed on what they have learned during the Geology unit of their Earth Science class. After conducting classroom and field studies on geology students will utilize this knowledge to interpret the rock layers and formation of the Grand Canyon. Outside of class students will read/review a website and complete a study guide to be reviewed by the teacher to assess students' learning. Following teacher review of study guides, the next class period(s) will be a discussion and questioning session(s) on the formation of the Grand Canyon.
Comparison of methods for geologic storage of carbon dioxide in saline formations
Goodman, Angela L. [U.S. DOE; Bromhal, Grant S. [U.S. DOE; Strazisar, Brian [U.S. DOE; Rodosta, Traci D. [U.S. DOE; Guthrie, William J. [U.S. DOE; Allen, Douglas E. [ORISE; Guthrie, George D. [U.S. DOE
Preliminary estimates of CO{sub 2} storage potential in geologic formations provide critical information related to Carbon Capture, Utilization, and Storage (CCUS) technologies to mitigate CO{sub 2} emissions. Currently multiple methods to estimate CO{sub 2} storage and multiple storage estimates for saline formations have been published, leading to potential uncertainty when comparing estimates from different studies. In this work, carbon dioxide storage estimates are compared by applying several commonly used methods to general saline formation data sets to assess the impact that the choice of method has on the results. Specifically, six CO{sub 2} storage methods were applied to thirteen saline formation data sets which were based on formations across the United States with adaptations to provide the geologic inputs required by each method. Methods applied include those by (1) international efforts ¢ the Carbon Sequestration Leadership Forum (Bachu et al., 2007); (2) United States government agencies ¢ U.S. Department of Energy ¢ National Energy Technology Laboratory (US-DOE-NETL, 2012) and United States Geological Survey (Brennan et al., 2010); and (3) the peer-reviewed scientific community ¢ Szulczewski et al. (2012) and Zhou et al. (2008). A statistical analysis of the estimates generated by multiple methods revealed that assessments of CO{sub 2} storage potential made at the prospective level were often statistically indistinguishable from each other, implying that the differences in methodologies are small with respect to the uncertainties in the geologic properties of storage rock in the absence of detailed site-specific characterization.
Use and Features of Basalt Formations for Geologic Sequestration
McGrail, B. Peter; Ho, Anita M.; Reidel, Steve P.; Schaef, Herbert T.
Extrusive lava flows of basalt are a potential host medium for geologic sequestration of anthropogenic CO2. Flood basalts and other large igneous provinces occur worldwide near population and power-producing centers and could securely sequester a significant fraction of global CO2 emissions. We describe the location, extent, and general physical and chemical characteristics of large igneous provinces that satisfy requirements as a good host medium for CO2 sequestration. Most lava flows have vesicular flow tops and bottoms as well as interflow zones that are porous and permeable and serve as regional aquifers. Additionally, basalt is iron-rich, and, under the proper conditions of groundwater pH, temperature, and pressure, injected CO2 will react with iron released from dissolution of primary minerals in the basalt to form stable ferrous carbonate minerals. Conversion of CO2 gas into a solid form was confirmed in laboratory experiments with supercritical CO2 in contact with basalt samples from Washington state.
River-aquifer interactions, geologic heterogeneity, and low-flow management
Fleckenstein, J.H.; Niswonger, R.G.; Fogg, G.E.
Low river flows are commonly controlled by river-aquifer exchange, the magnitude of which is governed by hydraulic properties of both aquifer and aquitard materials beneath the river. Low flows are often important ecologically. Numerical simulations were used to assess how textural heterogeneity of an alluvial system influences river seepage and low flows. The Cosumnes River in California was used as a test case. Declining fall flows in the Cosumnes River have threatened Chinook salmon runs. A ground water-surface water model for the lower river basin was developed, which incorporates detailed geostatistical simulations of aquifer heterogeneity. Six different realizations of heterogeneity and a homogenous model were run for a 3-year period. Net annual seepage from the river was found to be similar among the models. However, spatial distribution of seepage along the channel, water table configuration and the level of local connection, and disconnection between the river and aquifer showed strong variations among the different heterogeneous models. Most importantly, the heterogeneous models suggest that river seepage losses can be reduced by local reconnections, even when the regional water table remains well below the riverbed. The percentage of river channel responsible for 50% of total river seepage ranged from 10% to 26% in the heterogeneous models as opposed to 23% in the homogeneous model. Differences in seepage between the models resulted in up to 13 d difference in the number of days the river was open for salmon migration during the critical fall months in one given year. Copyright ?? 2006 The Author(s).
Color heterogeneity of the surface of PHOBOS - Relationships to geologic features and comparison to meteorite analogs
NASA Astrophysics Data System (ADS)
Murchie, S. L.; Britt, D. T.; Head, J. W.; Pratt, S. F.; Fisher, P. C.; Zhukov, B. S.; Kuzmin, A. A.; Ksanfomality, L. V.; Zharkov, A. V.; Nikitin, G. E.; Fanale, F. P.; Blaney, D. L.; Bell, J. F.; Robinson, M. S.
Color ratio images created from multispectral observations of Phobos are analyzed in order to characterize the spectral properties of Phobos' surface, to assess their spatial distributions and relationships with geologic features, and to compare Phobos' surface materials with possible meteorite analogs. Data calibration and processing is briefly discussed, and the observed spectral properties of Phobos and their lateral variations are examined. Attention is then given to the color properties of different types of impact craters, the origin of lateral variations in surface color, the relation between the spatial distribution of color properties and independently identifiable geologic features, and the relevance of color variation spatial distribution to the origin of the grooves.
Modeling Heterogeneous CINO2 Formation, Chloride Availability, and Chlorine Cycling in Southeast Texas
Nitryl chloride (ClNO2) mixing ratios above 1 ppbv have been measured off the coast of Southeast Texas. ClNO2 formation, the result of heterogeneous N205 uptake on chloride-containing aerosols, has a significant impact on oxidant form...
Engineering-geological conditions of the formations in the Western Thessaly basin, Greece
NASA Astrophysics Data System (ADS)
Apostolidis, Emmanuel; Koukis, George
An engineering-geological map of the Western Thessaly basin has been compiled, providing a valuable guide to both urban planning and industrial development of the wider area. This map contributes significantly to the optimization of land use and improved planning of technical work. Additionally, the engineering-geological conditions of the formations encountered in the Western Thessaly basin are examined. The formations are grouped into thirteen (13) engineering-geological entities, with regard to their geotechnical behaviour. This entire study was based on both in situ investigations and geotechnical information extracted from 1,039 boreholes. Furthermore, a landslide inventory map of the Western Thessaly basin has been compiled. In addition, the surface subsidence ruptures, due to ground-water overexploitation, have been examined in the eastern part of the study area.
Multi-Scale Characterization of an Heterogeneous Aquifer Through the Integration of Geological,
Sailhac, Pascal
the joint geological analysis of cores Oil & Gas Science and Technology Ł Rev. IFP, Vol. 62 (2007), No. 3, pp. 347-373 Copyright ® 2007, Institut franńais du pķtrole DOI: 10.2516/ogst:2007029 #12;Oil & Gas -- This paper presents the integrated modelling study of an experimental hydrogeological site recently developed
CO2 leakage risk in 3D heterogeneous formations
NASA Astrophysics Data System (ADS)
Hou, Z.; Murray, C. J.; Rockhold, M. L.
In this study we use a stochastic sensitivity analysis framework to evaluate the impact of 3D spatial heterogeneity in permeability on CO2 leakage risk. The leakage is defined as the total mass of CO2 moving into the overburden through the caprock-overburden interface, in both gaseous and liquid (dissolved) phases. The entropy-based framework has the ability to quantify the uncertainty associated with the input parameters/factors in the form of prior pdfs (probability density functions). Effective sampling of the prior pdfs enables us to explore the parameter space and systematically evaluate the individual and combined effects of the factors/parameters of interest on CO2 leakage risk. The parameters that are considered in the study include: mean, variance, and horizontal to vertical spatial anisotropy ratio for caprock permeability, and those same parameters for reservoir permeability. Given the sampled spatial variogram parameters, multiple realizations of permeability fields were generated using GSLIB subroutines. For each permeability field, a numerical simulator STOMP (water-salt-CO2-energy operational mode) is used to simulate the CO2 migration within the reservoir and caprock up to 50 years after injection. Due to intensive computational demand, a scalable version simulator, eSTOMP, is run on the Jaguar supercomputer. We then perform statistical analyses and summarize the relationships between the parameters of interest (mean/variance/anisotropy ratio of caprock/reservoir permeability) and CO2 leakage ratio. We will also present the effects of those parameters on CO2 plume radius and reservoir injectivity.
Toran, Laura
The results of electrical resistivity surveys using cables both surface-towed and stationary (lake- bottom heterogeneities that control groundwater-surface water interaction, as well as for imaging road-salt contamination contamination revealed a plume-shaped feature of low resistivity. Low resistivity and high chloride content were
Natural iodine in a clay formation: Implications for iodine fate in geological disposals
Paris-Sud XI, Universitķ de
1 Natural iodine in a clay formation: Implications for iodine fate in geological disposals F. Corresponding author: firstname.lastname@example.com To be submitted to Geochimica Acta Abstract Iodine is one of the most to considerable debate. The present study aims at providing new insights into this aspect of the iodine problem
A geological and engineering reservoir characterization of the Caballos Formation (Cretaceous), Puerto Colon field Putumayo basin, Colombia
Ruiz Castellanos, Hector
A GEOLOGICAL AND ENGINEERING RESERVOIR CHARACTERIZATION OF THE CABALLOS FORMATION (CRETACEOUS), PUERTO COLON FIELD, PUTUMAYO BASIN, COLOMBIA A Thesis by HECTOR RUIZ CASTELLANOS Submitted to Texas A&M University in partial fulfillment...: Petroleum Engineering ABSTRACT A Geological and Engineering Reservoir Characterization of the Caballos Formation (Cretaceous), Puerto Colon Field Putumayo Basin Colombia. (December 1994) Hector Ruiz Castellanos, B. S. , Universidad Industrial de...
Sedimentological and Petrophysical Heterogeneity of Glaciogenic Paleovalley, Late Ordovician Sarah Formation, Central Saudi Arabia
NASA Astrophysics Data System (ADS)
Razzaq, Waseem; Abdullatif, Osman; Sahin, Ali; Hariri, Mustafa
The Late Ordovician Sarah Formation deposited in glaciogenic environment, mainly dominated by braided river outwash system. Compared to the subsurface, the Sarah formation is considered as important tight gas sandstone reservoir at southern and northern parts of Saudi Arabia. Ten outcrops from Al-Ilb paleochannel were studied in detail to identify the heterogeneity in terms of the types and distribution of facies and related petrophysical properties. The Sarah Formation shows highly heterogeneous behavior at all scales. The main facies observed at Al-Ilb paleovalley are 64% trough-cross bedded sandstone, 23% horizontally stratified sandstone facies, and 2% massive conglomerates are observed at the proximal, medial and distal parts of the paleovalley. The remaining facies are trough-cross bedded sandstone facies that is laterally changes to horizontally stratified sandstone facies and in some cases to planner cross-bedded sandstone facies. The petrophysical analysis revealed good quality of porosity present in all parts of paleovalley. On the other hand the permeability values are high and ranging between 53mD to 5D. The descriptive statistics clearly indicate the normal distribution of porosity values for proximal, medial and distal parts of paleovalley and can be described as homogeneous. For permeability the distribution is heterogeneous as it is log-normally distributed. The scatter plots of porosity versus horizontal and vertical permeability shows very poor correlation for each part of paleochannel. This heterogeneity is attributed to depositional and post-depositional viabilities. These variables are grain size and shape distribution, sorting, packing, distribution of matrix and cementing material, and the presence of clays like kaolinite, smectite, and palygorskite. These observations further indicate that Sarah Formation is affected by shallow burial conditions during diagenesis. However, Sarah Formation shows highly heterogeneous behavior at outcrop scale that might be unpredictable and challenging in the subsurface.
Approaches to large scale unsaturated flow in heterogeneous, stratified, and fractured geologic media
Ababou, R.
This report develops a broad review and assessment of quantitative modeling approaches and data requirements for large-scale subsurface flow in radioactive waste geologic repository. The data review includes discussions of controlled field experiments, existing contamination sites, and site-specific hydrogeologic conditions at Yucca Mountain. Local-scale constitutive models for the unsaturated hydrodynamic properties of geologic media are analyzed, with particular emphasis on the effect of structural characteristics of the medium. The report further reviews and analyzes large-scale hydrogeologic spatial variability from aquifer data, unsaturated soil data, and fracture network data gathered from the literature. Finally, various modeling strategies toward large-scale flow simulations are assessed, including direct high-resolution simulation, and coarse-scale simulation based on auxiliary hydrodynamic models such as single equivalent continuum and dual-porosity continuum. The roles of anisotropy, fracturing, and broad-band spatial variability are emphasized. 252 refs.
A geological approach to characterizing aquifer heterogeneity. Completion report, 1990--1994
Phillips, F.; Wilson, J.; Gutjahr, A.
Spatial variations of hydraulic conductivity have generally been recognized as the dominant medium-independent control on the transport and dispersion of contaminants in groundwater. Mathematical models that use statistical descriptions of the hydraulic conductivity spatial distribution are available to predict contaminant transport. Such models are expected to be major tools in dealing with contamination problems at DOE sites. Unfortunately, the statistical parameters needed for such models can usually only be obtained through geostatistical analysis of very large numbers of hydraulic conductivity measurements, with associated large costs and often-significant human risk at highly contaminated sites. More accurate and realistic conceptual models for the actual distribution of hydraulic conductivity, requiring fewer field data, would increase the reliability of contaminant transport predictions while decreasing their cost. The objectives of the project can therefore be summarized in the following question: How can the data requirements for geostatistical analysis of hydraulic parameters be reduced by incorporation of geological expertise and macroscopic proxy information into new mathematical models. Specifically, the authors proposed to combine intensive geological field observations with permeability measurements to discover relationships between sediment depositional processes, geological structures, and the geostatistics of the permeability distributions that result.
Heterogeneity and Reservoir Quality of Yabus and Samaa Formations, Agordeed Field, Melut Rift Basin, Sudan
NASA Astrophysics Data System (ADS)
Badi, Amani; Ali, Omer; Farwa, Abdalla; Abdullatif, Osman
The Tertiary Yabus and Samaa Formations occur within the Melut Rift basin of interior Sudan which is regionally linked to the central and west African rift system. Yabus and Samaa Formations in Agordeed oil field are ones of the most productive oil reservoirs in Melut basin and are composed of sandstones and mudstones lithofacies that differ in size and length along and across the basin. The reservoir sandstone, which occurs at shallow burial depth, deposited within fluvial/lacustrine environments. This work aims to describe and characterize the reservoir heterogeneity and to investigate their impact on reservoir quality and architecture. This study employed a multidisciplinary and integrated approach that investigated and synthesized stratigraphic, sedimentological, cores, logs, petrographical, petrophysical and seismic data from Agordeed oil field. The stratigraphic and lithofacies analysis indicated that Yabus and Samaa formations vary systematically in their facies, sequences and stacking patterns within the basin. Reservoir heterogeneity exists at multiple scales, where reservoir sandstones macro- and micro scale heterogeneity shows vertical and lateral variations along and across the basin. These variations reflect the tectonic, depositional and post depositional controls within the proximal to distal fluvial, prodelta and lacustrine environments. The porosity and permeability distributions are controlled by the heterogeneities within the reservoir formation, such as stratigraphic layering, facies, diagenetic processes, and fracturing. Porosity is enhanced by extensive fracturing and grain dissolution creating intergranular, intragranular and moldic porosity. In addition, permeability is also increased by fractures connecting separated the buildups, that affect directly the reservoir quality. Assessing the different scales of heterogeneity is important to understand their impact on reservoir quality and architecture in Agordeed Field.
Geological study of uranium potential of the Kingston Peak Formation, Death Valley Region, California
Carlisle, D.; Kettler, R.M.; Swanson, S.C.
The results of a geological survey of the Kingston Peak Formation on the western slope of the Panamint Range near Death Valley are discussed. The geology of the Panamint mountains was mapped on topographic base maps of the Telescope Peak and Manly Peak quadrangles. Radiometric suveys of the area were conducted using gamma ray spectrometers. Samples of the conglomerate were analyzed using delayed neutron, neutron activation, atomic absorption, and LECO analysis. It is concluded that uranium mineralization in the Favorable Submember is significant and further exploration is warranted. The monazite-fenotime related uranium and thorium mineralization in the Mountain Girl quartz pebble conglomerate is of no economic interest. (DMC)
Geologic Observations and Numerical Modeling: A Combined Approach to Understanding Crater and Basin Formation and Structure
NASA Astrophysics Data System (ADS)
Potter, R. W. K.; Head, J. W., III
Impact cratering is a fundamental geological process throughout the Solar System. The Moon is an ideal location to document the impact cratering process due to the number and excellent state of preservation of large craters and basins, and the wide range of geological, geophysical, topographic, mineralogic, remote sensing and returned sample data. Despite the number and excellent preservation state of many large complex craters and basins, their formation and the origin of their structural features and the stages in their evolution remain contentious. To more comprehensively document the final stage of lunar impact basin formation, we have compiled detailed topographic, geological and mineralogic maps of several type examples of peak-ring and multi-ring basins, including the Orientale basin. These data include the mineralogic characteristics of basin ring structures and assist in the interpretation of the target stratigraphy, and the depth of origin of basin rings. Data for the current structure of basins is compared to numerical model outputs of basin-forming impacts, which track formation to the conclusion of dynamic processes (2 to 3 hours after impact). We use the Orientale basin as an example and provide combined correlations and interpretations that assign rings to various stages in the numerical models, and compare these candidates to crustal stratigraphy, with the ultimate aim of producing a consistent model for large crater/basin formation. The shock physics code iSALE is used to numerically model the basin-scale impacts. Constitutive equations and equations of state for materials analogous to the lunar crust (gabbroic anorthosite) and mantle (dunite) are used. Aspects of the numerically-produced lunar basins (e.g., material distribution and accumulated stress) are compared and contrasted to remote observations and geological maps of the Orientale rings and geological units, including ejecta and impact melt deposits.
Thermal state and complex geology of a heterogeneous salty crust of Jupiter's satellite, Europa
NASA Astrophysics Data System (ADS)
Prieto-Ballesteros, Olga; Kargel, Jeffrey S.
The complex geology of Europa is evidenced by many tectonic and cryomagmatic resurfacing structures, some of which are "painted" into a more visible expression by exogenic alteration processes acting on the principal endogenic cryopetrology. The surface materials emplaced and affected by this activity are mainly composed of water ice in some areas, but in other places there are other minerals involved. Non-ice minerals are visually recognized by their low albedo and reddish color either when first emplaced or, more likely, after alteration by Europan weathering processes, especially sublimation and alteration by ionizing radiation. While red chromophoric material could be due to endogenic production of solid sulfur allotropes or other compounds, most likely the red substance is an impurity produced by radiation alteration of hydrated sulfate salts or sulphuric acid of mainly internal origin. If the non-ice red materials or their precursors have a source in the satellite interior, and if they are not merely trace contaminants, then they can play an important role in the evolution of the icy crust, including structural differentiation and the internal dynamics. Here we assume that these substances are major components of Europa's cryo/hydrosphere, as some models have predicted they should be. If this is an accurate assumption, then these substances should not be neglected in physical, chemical, and biological models of Europa, even if major uncertainties remain as to the exact identity, abundance, and distribution of the non-ice materials. The physical chemical properties of the ice-associated materials will contribute to the physical state of the crust today and in the geological past. In order to model the influence of them on the thermal state and the geology, we have determined the thermal properties of the hydrated salts. Our new lab data reveal very low thermal conductivities for hydrated salts compared to water ice. Lower conductivities of salty ice would produce steeper thermal gradients than in pure ice. If there are salt-rich layers inside the crust, forming salt beds over the seafloor or a briny eutectic crust, for instance, the high thermal gradients may promote endogenic geological activity. On the seafloor, bedded salt accumulations may exhibit high thermochemical gradients. Metamorphic and magmatic processes and possible niches for thermophilic life at shallow suboceanic depths result from the calculated thermal profiles, even if the ocean is very cold.
Universitt StuttgartInstitut fr Wasserbau, Lehrstuhl fr Hydromechanik und Hydrosystemmodellierung Workshop on Numerical Models for Carbon Dioxide Storage in Geological Formations
Cirpka, Olaf Arie
Hydrosystemmodellierung Workshop on Numerical Models for Carbon Dioxide Storage in Geological Formations 1/16 Modelling April 2008 Workshop on Numerical Models for Carbon Dioxide Storage in Geological Formations #12 on Numerical Models for Carbon Dioxide Storage in Geological Formations 2/16 CO2 leakage mitigation using
Paleomagnetic dating of continental geological formations: Strong diachronism evidenced in the Saharan platform and geodynamical implications
NASA Astrophysics Data System (ADS)
Henry, B.; Derder, M. E. M.; Amenna, M.; Maouche, S.; Bayou, B.; Ouabadi, A.; Bouabdallah, H.; Beddiaf, M.; Ayache, M.; Bestandji, R.
The paleomagnetism is a powerful tool to date formations that have age not constrained by paleontological, stratigraphical or radiochronological data. It was applied, on the western border of the Murzuq basin in Algeria (Saharan platform), to the Zarza'tine formation, attributed to a Middle-Upper Triassic-Lower Jurassic age. Comparison of the obtained paleomagnetic pole with previous poles from the same geological formation outcropping in another basin and from other Carboniferous to Lower Mesozoic African formations yielded a clearly older age (Late Permian) than expected. That evidences a strong diachronism (at least 40 My) of the deposition of this formation on the Saharan platform. The post-Hercynian structural evolution was therefore different according to the parts of this platform, with significant differential vertical tectonic movements. The latter were at the origin of erosion, hiatus or sediments deposition according to areas.
Numerical evaluation of apparent transport parameters from forced-gradient tracer tests in statistically anisotropic heterogeneous formations
NASA Astrophysics Data System (ADS)
Pedretti, D.; Fernandez-Garcia, D.; Bolster, D.; Sanchez-Vila, X.; Benson, D.
For risk assessment and adequate decision making regarding remediation strategies in contaminated aquifers, solute fate in the subsurface must be modeled correctly. In practical situations, hydrodynamic transport parameters are obtained by fitting procedures, that aim to mathematically reproduce solute breakthrough (BTC) observed in the field during tracer tests. In recent years, several methods have been proposed (curve-types, moments, nonlocal formulations) but none of them combine the two main characteristic effects of convergent flow tracer tests (which are the most used tests in the practice): the intrinsic non-stationarity of the convergent flow to a well and the ubiquitous multiscale hydraulic heterogeneity of geological formations. These two effects separately have been accounted for by a lot of methods that appear to work well. Here, we investigate both effects at the same time via numerical analysis. We focus on the influence that measurable statistical properties of the aquifers (such as the variance and the statistical geometry of correlation scales) have on the shape of BTCs measured at the pumping well during convergent flow tracer tests. We built synthetic multigaussian 3D fields of heterogeneous hydraulic conductivity fields with variable statistics. A well is located in the center of the domain to reproduce a forced gradient towards it. Constant-head values are imposed on the boundaries of the domains, which have 251x251x100 cells. Injections of solutes take place by releasing particles at different distances from the well and using a random walk particle tracking scheme with constant local coefficient of dispersivity. The results show that BTCs partially display the typical anomalous behavior that has been commonly referred to as the effect of heterogeneity and connectivity (early and late arrival times of solute differ from the one predicted by local formulations). Among the most salient features, the behaviors of BTCs after the peak (the slope of the BTCs in log-log scales, which is the diagnostic plot to infer power-law type nonlocal distribution parameters due to hydraulic heterogeneity) indicate that anisotropy generates apparent higher capacity coefficients in certain directions. At very late times, however, the slopes display similar values, indicating that at these spatial scales (injection distances comparable with the integral scales), particles are stacked in low K areas for much longer than the advection times in higher K zones.
Method for Controlling a Producing Zone of a Well in a Geological Formation
NASA Technical Reports Server (NTRS)
Arndt, G. Dickey (Inventor); Carl, James R. (Inventor); Byerly, Kent A. (Inventor); Amini, B. Jon (Inventor)
System and methods for transmitting and receiving electromagnetic pulses through a geological formation. A preferably programmable transmitter having an all-digital portion in a preferred embodiment may be operated at frequencies below 1 MHz without loss of target resolution by transmitting and over sampling received long PN codes. A gated and stored portion of the received signal may be correlated with the PN code to determine distances of interfaces within the geological formation, such as the distance of a water interfaces from a wellbore. The received signal is oversampled preferably at rates such as five to fifty times as high as a carrier frequency. In one method of the invention, an oil well with multiple production zones may be kept in production by detecting an approaching water front in one of the production zones and shutting down that particular production zone thereby permitting the remaining production zones to continue operating.
Modulation format identification in heterogeneous fiber-optic networks using artificial neural networks.
Khan, Faisal Nadeem; Zhou, Yudi; Lau, Alan Pak Tao; Lu, Chao
We propose a simple and cost-effective technique for modulation format identification (MFI) in next-generation heterogeneous fiber-optic networks using an artificial neural network (ANN) trained with the features extracted from the asynchronous amplitude histograms (AAHs). Results of numerical simulations conducted for six different widely-used modulation formats at various data rates demonstrate that the proposed technique can effectively classify all these modulation formats with an overall estimation accuracy of 99.6% and also in the presence of various link impairments. The proposed technique employs extremely simple hardware and digital signal processing (DSP) to enable MFI and can also be applied for the identification of other modulation formats at different data rates without necessitating hardware changes. PMID:22714229
FOREWORD: Heterogenous nucleation and microstructure formationŚa scale- and system-bridging approach Heterogenous nucleation and microstructure formationŚa scale- and system-bridging approach
NASA Astrophysics Data System (ADS)
Emmerich, H.
Scope and aim of this volume. Nucleation and initial microstructure formation play an important role in almost all aspects of materials science [1-5]. The relevance of the prediction and control of nucleation and the subsequent microstructure formation is fully accepted across many areas of modern surface and materials science and technology. One reason is that a large range of material properties, from mechanical ones such as ductility and hardness to electrical and magnetic ones such as electric conductivity and magnetic hardness, depend largely on the specific crystalline structure that forms in nucleation and the subsequent initial microstructure growth. A very demonstrative example for the latter is the so called bamboo structure of an integrated circuit, for which resistance against electromigration [6] , a parallel alignment of grain boundaries vertical to the direction of electricity, is most favorable. Despite the large relevance of predicting and controlling nucleation and the subsequent microstructure formation, and despite significant progress in the experimental analysis of the later stages of crystal growth in line with new theoretical computer simulation concepts [7], details about the initial stages of solidification are still far from being satisfactorily understood. This is in particular true when the nucleation event occurs as heterogenous nucleation. The Priority Program SPP 1296 'Heterogenous Nucleation and Microstructure FormationŚa Scale- and System-Bridging Approach' [8] sponsored by the German Research Foundation, DFG, intends to contribute to this open issue via a six year research program that enables approximately twenty research groups in Germany to work interdisciplinarily together following this goal. Moreover, it enables the participants to embed themselves in the international community which focuses on this issue via internationally open joint workshops, conferences and summer schools. An outline of such activities can be found in [8]. Furthermore, the honorable invitation to publish a special issue in Journal of Physics: Condensed Matter dedicated to the Priority Program's topic allows the obtained results to be communicated to relevant international colleagues, which stimulates further interest and encourages future collaborations. The issue comprises the research results of the participants during the first two year period of the Priority Program as well as that of the international referees of the program. Now, what precisely is the research concept of the Priority Program and thus, what are the articles in this special issue dedicated to? Ever since the pioneering work of Volmer and Weber [9], Becker and D÷ring [10] as well as Turnbull and Fisher [11] nucleation has been modelled more or less phenomenologically. These traditional models describe nucleation by stochastic processes of single atoms, respectively, molecules, which attach at primary droplets. Those thereby growing droplets become stable by reaching a critical size. This concept has largely been employed to model thermal activated first-order phase transformations. However it contains basic weak points, which raises the question of its physical justification. For instance, the dependence of the interfacial free energy on the critical size of a nucleus isŚfrom the point of view of recent experimentsŚnot considered adequately. In the past years, several advances have been performed to put the modelling of nucleation and microstructure formation on a wider base [12-15]. Figure 1 Figure 1. Illustration of the interdisciplinary approach in the Research Priority Program 'Nucleation and Growth Kinetics in Colloids and MetalsŚSteps towards a Scale- and System-Bridging Understanding' [8]: to advance towards a system- and scale-bridging detailed understanding of the energetics and kinetics of heterogeneous nucleation and micro-structure formation, two different experimental (binary colloids and binary metallic alloys) model systems are investigated jointly by experimental scientists working with different experimental tech
CO2 Plume Estimation with Automatic Calibration of TOUGH Model for Carbon Sequestration in Geological Formations
NASA Astrophysics Data System (ADS)
Espinet, A. J.; Shoemaker, C. A.; Doughty, C.
In order to assure safe carbon sequestration in geological formations, estimation of the CO2 plume from monitoring data is needed. We investigate methodologies to use field measurements and numerical simulations to find the plume position and to obtain a better understanding of the interaction of different mechanisms that govern the CO2 flow in the geological formation. The challenge is to be able to give an accurate prognosis of the plume location while dealing with uncertainties and model error. We use the TOUGH2 program, which is a numerical simulator for multi-phase fluid and heat flow in porous and fractured media, along with the ECO2N module, specific for CO2 flow in brine. This model describes the coupling of flow and geological processes. We also use the optimization program ORBIT to calibrate the model parameters. ORBIT (Optimization by Radial Basis Function Interpolation in Trust-Regions) has proven to be computationally efficient for environmental models that are computationally expensive. It is a derivative-free method, which makes it easier to use in conjunction with a complex nonlinear simulation model. We use a three-dimensional saline aquifer for the application.
Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site
Lin, Xueju; Kennedy, David W.; Fredrickson, Jim K.; Bjornstad, Bruce N.; Konopka, Allan
Microbial diversity in subsurface sediments at the Hanford Site 300 Area near Richland, Washington State (USA) was investigated by analyzing samples recovered from depths of 9 to 52 m. Approximately 8000 near full-length 16S rRNA gene sequences were analyzed across geological strata that include a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (Operational Taxonomic Units at the 97% identity level), respectively. Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (Chao1 estimator) was highest (>700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic interface, richness was about 325 and declined to less than 50 in the deeper reduced zones. The deeper Ringold strata were characterized by a preponderance (ca. 90%) of Proteobacteria. The Bacterial community in the oxic sediments contained not only members of 9 well-recognized phyla but also an unusually high proportion of 3 candidate divisions (GAL15, NC10, and SPAM). Additionally, novel phylogenetic orders were identified within the Delta-proteobacteria, a clade rich in microbes that carry out redox transformations of metals that are important contaminants on the Hanford Site.
Vertical stratification of subsurface microbial community composition across geological formations at the Hanford Site.
Lin, Xueju; Kennedy, David; Fredrickson, Jim; Bjornstad, Bruce; Konopka, Allan
Microbial diversity in subsurface sediments at the Hanford Site 300 Area near Richland, Washington state (USA) was investigated by analysing 21 samples recovered from depths of 9-52?m. Approximately 8000 near full-length 16S rRNA gene sequences were analysed across geological strata that include a natural redox transition zone. These strata included the oxic coarse-grained Hanford formation, fine-grained oxic and anoxic Ringold Formation sediments, and the weathered basalt group. We detected 1233 and 120 unique bacterial and archaeal OTUs (operational taxonomic units at the 97% identity level) respectively. Microbial community structure and richness varied substantially across the different geological strata. Bacterial OTU richness (Chao1 estimator) was highest (>?700) in the upper Hanford formation, and declined to about 120 at the bottom of the Hanford formation. Just above the Ringold oxic-anoxic interface, richness was about 325 and declined to less than 50 in the deeper reduced zones. The deeper Ringold strata were characterized by a preponderance (c. 90%) of Proteobacteria. The bacterial community in the oxic sediments contained not only members of nine well-recognized phyla but also an unusually high proportion of three candidate divisions (GAL15, NC10 and SPAM). Additionally, 13 novel phylogenetic orders were identified within the Deltaproteobacteria, a clade rich in microbes that carry out redox transformations of metals that are important contaminants on the Hanford Site. PMID:22122741
NSDL National Science Digital Library
Alec Bodzin
Geologic Explorations allows learners to explore a variety of unique geological formations of Utah using Quicktime Virtual Reality (QTVR) panoramas and digital still imagery. Spectacular panoramas and striking images capture Utah's unique geology and invite students to explore and learn interesting facts and concepts central to the study of geology.
Using specific capacity ratios to estimate groundwater yield by geologic formation
Hordon, R.M.
Groundwater yield estimates for geologic formations in consolidated rock areas would be of great value to communities which are interested in development density recommendations for those areas without public water and sewer. One method of estimating groundwater yield is to separate the hydrograph into stormflow and baseflow, and then assume the latter represents the yield from a watershed. The problem is that most watersheds have more than one formation. Therefore, the following procedures are suggested as a means of estimating yield on a formation basis: 1) use well records only when the drawdown data reflect a pumping test of 4 hours or more; 2) calculate the geometric mean of the specific capacity values of the selected wells within the study area for each formation; 3) perform hydrography separation for the basin in the study area which is underlain by one formation (called A); 4) determine the geometric mean specific capacity ratios between each formation and A; 5) multiply the yield obtained for formation A (by hydrography separation) by the appropriate ratio, on the assumption that aquifer yields should be better with higher specific capacity values. The method has beenapplied to selected areas in New Jersey.
Characterization of the Geologic Setting of Recurring Slope Lineae: Constraints on Their Formation Mechanism
NASA Astrophysics Data System (ADS)
Watkins, J.; Ojha, L.; Reith, R. C.; Yin, A.
Recurring Slope Lineae (RSL) are seasonal, low albedo features that originate at the base of bedrock outcrops and extend down steep, equator-facing, mid-latitude and equatorial rocky slopes of Mars. They exhibit progressive growth in the downslope direction during warm seasons, diverting around topographic obstacles, and fade during cold seasons. Slopes containing RSL appear to be sites of geologically very recent activity, including 'fresh' impact craters and active mass wasting, and are also associated with numerous small channels and bright fans. Based on their seasonal growth and strong dependency on latitude and slope aspect, RSL formation has been attributed to the seepage and downslope transport of a salt-bearing (briny), water-based liquid (potentially melted) through porous regolith near the surface. The seepage of this liquid wets and thus darkens the RSL surface, and evaporates once seasonal flow ceases. However, the source of this water, and an active recharge mechanism to maintain this source over even short geological timescales, are not currently understood. Subsurface groundwater is one possible source for the amount of liquid required to fill pore spaces between particles and create a hydraulic gradient to initiate and maintain water flow to the surface. Preexisting structural inhomogeneities, including faults, fractures, and joints, may act as conduits for subsurface fluid migration, supporting groundwater exploitation of routes of increased permeability. To investigate this fault-controlled brine flow hypothesis, morphological mapping of RSL slope surfaces is performed. Preliminary analysis of these geologic settings suggests a spatial correlation between RSL sites and fault related morphology, including linear features and offsets, transtensional features, sub parallel zones, and multiple styles of brittle deformation. This detailed, systematic study characterizing the geologic context of all confirmed RSL sites as well as of observed locations that present a setting favorable to RSL but without the presence of RSL, further explores this correlation, constraining plausible RSL formation mechanisms.
Formation of HCN+ in Heterogeneous Reactions of N2+ and N+ with Surface Hydrocarbons
A significant increase of the ion yield at m/z 27 in collisions of low-energy ions of N2+ and N+ with hydrocarbon-covered room-temperature or heated surfaces of tungsten, carbon-fiber composite, and beryllium, not observed in analogous collisions of Ar+, is ascribed to the formation of HCN+ in heterogeneous reactions between N2+ or N+ and surface hydrocarbons. The formation of HCN+ in the reaction with N+ indicated an exothermic reaction with no activation barrier, likely to occur even at very low collision energies. In the reaction with N2+, the formation of HCN+ was observed to a different degree on these room-temperature and heated (150 and 300 ░C) surfaces at incident energies above about 50 eV. This finding suggested an activation barrier or reaction endothermicity of the heterogeneous reaction of about 3¢3.5 eV. The main process in N2+ or N+ interaction with the surfaces is ion neutralization; the probability of forming the reaction product HCN+ was very roughly estimated for both N2+ and N+ ions to about one in 104 collisions with the surfaces. PMID:23614645
Experiences with the Application of Services Oriented Approaches to the Federation of Heterogeneous Geologic Data Resources
NASA Astrophysics Data System (ADS)
Cervato, C.; Fils, D.; Bohling, G.; Diver, P.; Greer, D.; Reed, J.; Tang, X.
The federation of databases is not a new endeavor. Great strides have been made e.g. in the health and astrophysics communities. Reviews of those successes indicate that they have been able to leverage off key cross-community core concepts. In its simplest implementation, a federation of databases with identical base schemas that can be extended to address individual efforts, is relatively easy to accomplish. Efforts of groups like the Open Geospatial Consortium have shown methods to geospatially relate data between different sources. We present here a summary of CHRONOS's (http://www.chronos.org) experience with highly heterogeneous data. Our experience with the federation of very diverse databases shows that the wide variety of encoding options for items like locality, time scale, taxon ID, and other key parameters makes it difficult to effectively join data across them. However, the response to this is not to develop one large, monolithic database, which will suffer growth pains due to social, national, and operational issues, but rather to systematically develop the architecture that will enable cross-resource (database, repository, tool, interface) interaction. CHRONOS has accomplished the major hurdle of federating small IT database efforts with service-oriented and XML-based approaches. The application of easy-to-use procedures that allow groups of all sizes to implement and experiment with searches across various databases and to use externally created tools is vital. We are sharing with the geoinformatics community the difficulties with application frameworks, user authentication, standards compliance, and data storage encountered in setting up web sites and portals for various science initiatives (e.g., ANDRILL, EARTHTIME). The ability to incorporate CHRONOS data, services, and tools into the existing framework of a group is crucial to the development of a model that supports and extends the vitality of the small- to medium-sized research effort that is essential for a vibrant scientific community. This presentation will directly address issues of portal development related to JSR-168 and other portal API's as well as issues related to both federated and local directory-based authentication. The application of service-oriented architecture in connection with ReST-based approaches is vital to facilitate service use by experienced and less experienced information technology groups. Application of these services with XML- based schemas allows for the connection to third party tools such a GIS-based tools and software designed to perform a specific scientific analysis. The connection of all these capabilities into a combined framework based on the standard XHTML Document object model and CSS 2.0 standards used in traditional web development will be demonstrated. CHRONOS also utilizes newer client techniques such as AJAX and cross- domain scripting along with traditional server-side database, application, and web servers. The combination of the various components of this architecture creates an environment based on open and free standards that allows for the discovery, retrieval, and integration of tools and data.
Evidence for an additional uppermost geological unit in the Medusae Fossae Formation, Equatorial Mars
NASA Astrophysics Data System (ADS)
Harrison, Samantha; Balme, Matt; Hagermann, Axel
The Medusae Fossae Formation (MFF) is a geological formation comprising three geological units (members) spread across five principal outcrops. The MFF dominates roughly a quarter of the longitudinal extent of the equatorial region of Mars, extending east-west across a distance of ~ 5,500 km between the southern Elysium Planitia and the Tharsis region. The nature of these materials is often referred to as enigmatic, as their exact origin remains unknown. Harrison et al. (Icarus, 2010) presented new observations of outlying occurrences of MFF materials on the southern highlands, atop the dichotomy boundary. They presented two hypotheses to explain these observation: 1) the MFF had a much larger pre-erosional extent than previously thought or 2) these materials had initially been eroded from the main outcrops of the formation, then transported southward by wind and subsequently reworked. A subsequent extension of this work provided evidence for an even larger extent of outlying MFF materials, particularly around and south of the easternmost portions of the MFF. Here we present these new outlier data, together with new textural classification and facies mapping of this region of the MFF. These data show that MFF outlier textures, whilst external to the main MFF outcrops in many places, are also found superposing large areas of the "main" MFF formations. These data support the first of the two working hypotheses presented, but also suggest that these so-called outlying materials represent a previously unmapped, stratigraphically uppermost unit of the Medusae Fossae Formation. We also suggest that, based upon our own morphometric study of yardangs across members and analogue studies by de Silva et al. (Icarus, 2010), these represent a less indurated material than other units of the formation. In the overall context of the origins of the MFF, we find that our data are consistent with the Medusae Fossae materials being a large-scale ignimbrite complex, perhaps with multiple sources, including the Tharsis volcanic province.
Physical Constraints on Geologic CO2 Sequestration in Low-Volume Basalt Formations
Ryan M. Pollyea; Jerry P. Fairley; Robert K. Podgorney; Travis L. McLing
Deep basalt formations within large igneous provinces have been proposed as target reservoirs for carbon capture and sequestration on the basis of favorable CO2-water-rock reaction kinetics that suggest carbonate mineralization rates on the order of 102¢103 d. Although these results are encouraging, there exists much uncertainty surrounding the influence of fracture-controlled reservoir heterogeneity on commercial-scale CO2 injections in basalt formations. This work investigates the physical response of a low-volume basalt reservoir to commercial-scale CO2 injections using a Monte Carlo numerical modeling experiment such that model variability is solely a function of spatially distributed reservoir heterogeneity. Fifty equally probable reservoirs are simulated using properties inferred from the deep eastern Snake River Plain aquifer in southeast Idaho, and CO2 injections are modeled within each reservoir for 20 yr at a constant mass rate of 21.6 kg s¢1. Results from this work suggest that (1) formation injectivity is generally favorable, although injection pressures in excess of the fracture gradient were observed in 4% of the simulations; (2) for an extensional stress regime (as exists within the eastern Snake River Plain), shear failure is theoretically possible for optimally oriented fractures if Sh is less than or equal to 0.70SV; and (3) low-volume basalt reservoirs exhibit sufficient CO2 confinement potential over a 20 yr injection program to accommodate mineral trapping rates suggested in the literature.
Method of detecting leakage from geologic formations used to sequester CO.sub.2
White, Curt (Pittsburgh, PA); Wells, Arthur (Bridgeville, PA); Diehl, J. Rodney (Pittsburgh, PA); Strazisar, Brian (Venetia, PA)
The invention provides methods for the measurement of carbon dioxide leakage from sequestration reservoirs. Tracer moieties are injected along with carbon dioxide into geological formations. Leakage is monitored by gas chromatographic analyses of absorbents. The invention also provides a process for the early leak detection of possible carbon dioxide leakage from sequestration reservoirs by measuring methane (CH.sub.4), ethane (C.sub.2H.sub.6), propane (C.sub.3H.sub.8), and/or radon (Rn) leakage rates from the reservoirs. The invention further provides a method for branding sequestered carbon dioxide using perfluorcarbon tracers (PFTs) to show ownership.
On the accuracy of classic numerical schemes for modeling flow in saturated heterogeneous formations
NASA Astrophysics Data System (ADS)
Cainelli, Oscar; Bellin, Alberto; Putti, Mario
Quantitative hydrogeology often relies on numerical modeling of flow and transport processes in the earth subsurface. Despite the richness of numerical schemes proposed in the literature most applications are performed by using a few very popular codes based on classical finite volume or finite element techniques. An important limitation of these numerical schemes is that they lead to solutions that do not satisfy the refraction law of streamlines at element (or volume) edges. This is not of great concern when the hydraulic conductivity K is spatially homogeneous, or varies smoothly within the computational domain. However, the solution may deteriorate in heterogeneous formations with high contrast between the hydraulic conductivity of adjacent computational cells. We analyze the performance of four widely used classic numerical schemes for solving the flow equation when they are applied to heterogeneous porous media. We first analyze the convergence of the numerical schemes to a known analytical solution in a simple heterogeneous field composed by 4 blocks with contrasting hydraulic conductivities. Then we compare the numerical solutions obtained in both Gaussian and exponential weakly heterogeneous logconductivity fields with existing analytical first- and second-order solutions in the variance of the logconductivity field, ?Y2. Our analysis highlights that postprocessing the velocity field to enforce a posteriori the refraction law leads to biased results and that the performance of the numerical scheme depends on how mass conservation is discretized on the computational grid. Numerical schemes using inter-block conductivities, based for example on the harmonic mean, modify the spatial structure of the conductivity, with a negative impact on the structure of the velocity field.
Lithofacies and cyclicity of the Yates Formation, Permian basin: Implications for reservoir heterogeneity
Borer, J.M.; Harris, P.M. (Chevron Oil Field Research Co., La Habra, CA (United States))
Siliciclastics of the Yates Formation (Permian, upper Guadalupian) are significant hydrocarbon reservoirs in the US Permian basin. Subsurface and outcrop data show that the most porous lithofacies occur in a clastic-dominated middle shelf and that evaporitic inner shelf and carbonate outer shelf equivalents are mostly nonporous. Lithofacies relations and much of the heterogeneity in Yates reservoirs are related to the stacking of depositional sequences (i.e., siliciclastic-carbonate alternations and sandstone-argillaceous siltstone alternations) in response to three orders of orbitally forced, low-amplitude, eustatic variation. In general, siliciclastics dominated the Yates shelf during lowstand parts of asymmetric, 400-k.y. sea level fluctuations, whereas carbonates were deposited during sea level highstands. The character and position of sand depocenters on the Yates shelf during these lowstands were controlled by a longer duration third-order sea level variation. Shorter duration cycles controlled the heterogeneity within the 400-k.y. depositional sequences. The variation in cycle packaging, lithology, and reservoir quality between the Central Basin platform and Northwest shelf may be a response of eustatic variation on parts of the shelf with different slopes or subsidence profiles. The lithofacies described from the Yates Formation and the deposition model proposed to explain the stratigraphy may be valuable as analogs in other basins containing mixed siliciclastic-carbonate settings.
Heterogeneous Formation of Polar Stratospheric Clouds- Part 1: Nucleation of Nitric Acid Trihydrate (NAT)
NASA Technical Reports Server (NTRS)
Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooss, J.-U.; Peter, T.
Satellite-based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid-December 2009, a heterogeneous nucleation mechanism is required, occurring via immersion freezing on the surface of solid particles, likely of meteoritic origin. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along more than sixty thousand trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) observation points. Comparing the optical properties of the modelled NAT with these observations enabled a thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory, is simple to implement in models and provides substantial advantages over previous approaches which involved a constant rate of NAT nucleation in a given volume of air. It is shown that the new method is capable of reproducing observed polar stratospheric clouds (PSCs) very well, despite the varied conditions experienced by air parcels travelling along the different trajectories. In a companion paper, ZOMM is applied to a later period of the winter, when ice PSCs are also present, and it is shown that the observed PSCs are also represented extremely well under these conditions.
Geologic framework of the Jurassic (Oxfordian) Smackover Formation the Alabama coastal waters area
Tew, B.H.; Mancini, E.A. (Univ. of Alabama, Tuscaloosa, AL (United States)); Mink R.M.; Mann, S.D. (Geological Survey of Alabama, Tuscaloosa, AL (United States)); Mancini, E.A.
The Jurassic (Oxfordian) Smackover Formation is a prolific hydrocarbon-producing geologic unit in the onshore Gulf of Mexico area, including southwest Alabama. However, no Smackover strata containing commercial accumulations of oil or gas have thus far been discovered in the Alabama state coastal waters area (ACW). This study of the regional geologic framework of the Smackover Formation was done to characterize the unit in the ACW and to compare strata in the ACW with productive Smackover intervals in the onshore area. In the study area, the Smackover Formation was deposited on a highly modified carbonate associated with pre-Smackover topographic features. In the onshore Alabama, north of the Wiggins arch complex, an inner ramp developed in the area of the Mississippi interior salt basin and the Manila and Conecuh embayments. South of the Wiggins arch complex in extreme southern onshore Alabama and in the ACW, an outer ramp formed that was characterized by a much thicker Smackover section. In the outer ramp setting, four lithofacies associations are recognized: lower, middle, and upper outer ramp lithofacies (ORL) and the coastal dolostone lithofacies. The coastal dolostone lithofacies accounts for most of the reservoir-grade porosity in the outer ramp setting. The lower, middle, and upper ORL, for the most part, are nonporous. Volumetrically, intercrystalline porosity is the most important pore type in the coastal dolostone lithofacies. Numerous data in the ACW area indicate that halokinesis has created structural conditions favorable for accumulation and entrapment of oil and gas in the outer ramp lithofacies of the Smackover. Prolific hydrocarbon source rocks are present in the ACW, as evidenced by the significant natural gas accumulations in the Norphlet Formation. To date, however, reservoir quality rocks of the coastal dolostone lithofacies coincident with favorable structural conditions have not been encountered in the ACW.
An effect of CO2 leakage from deep geological formations on the quality of shallow aquifers
NASA Astrophysics Data System (ADS)
Wang, Sookyun; Nam, Ji Eun
Injection of CO2 into deep geological formations is a promising technique for Sequestration of large amount of CO2. If some fraction of the stored CO2 were to leak and reach shallow groundwater aquifers, however, it would lead to geochemical alteration that could have detrimental effects on the water quality. A series of experiments were performed on dissolution kinetics of a trace metal, galena, to evaluate the change in groundwater pH and the enhanced dissolution as carbon dioxide introduces into the aquifer. The conventional rate law was applied to obtain reaction parameters on dissolution kinetics for further modeling studies. The results from batch experiments and kinetic analysis were applied to develop a 1D mathematical model to simulate the fate and transport of dissolved trace metals in shallow aquifers. Results show that CO2 dissolution in groundwater aquifers can solubilize trace metals to levels that exceed drinking water standards. This approach allows for a reasonable assessment of the risks on tha quality of freshwater aquifers due to the escape of CO2 from deep geological formations.
Carbon Dioxide Capture and Storage: An Overview With Emphasis on Capture and Storage in Deep Geological Formations
Sally M. Benson; Terry Surles
A transition to a low-carbon economy can be facilitated by CO2 capture and storage. This paper begins with an overview of CO2 capture and storage in the terrestrial biosphere, oceans, and deep geologic systems. The remainder focuses on what now appears to be the most promising option for large-scale deployment-capture and storage in deep geologic formations. A detailed description of
Geologic setting, petrophysical characteristics, and regional heterogeneity patterns of the Smackover in southwest Alabama. Draft topical report on Subtasks 2 and 3
Kopaska-Merkel, D.C.; Mann, S.D.; Tew, B.H.
This is the draft topical report on Subtasks 2 and 3 of DOE contract number DE-FG22-89BC14425, entitled ``Establishment of an oil and gas database for increased recovery and characterization of oil and gas carbonate reservoir heterogeneity.`` This volume constitutes the final report on Subtask 3, which had as its primary goal the geological modeling of reservoir heterogeneity in Smackover reservoirs of southwest Alabama. This goal was interpreted to include a thorough analysis of Smackover reservoirs, which was required for an understanding of Smackover reservoir heterogeneity. This report is divided into six sections (including this brief introduction). Section two, entitled ``Geologic setting,`` presents a concise summary of Jurassic paleogeography, structural setting, and stratigraphy in southwest Alabama. This section also includes a brief review of sedimentologic characteristics and stratigraphic framework of the Smackover, and a summary of the diagenetic processes that strongly affected Smackover reservoirs in Alabama. Section three, entitled ``Analytical methods,`` summarizes all nonroutine aspects of the analytical procedures used in this project. The major topics are thin-section description, analysis of commercial porosity and permeability data, capillary-pressure analysis, and field characterization. ``Smackover reservoir characteristics`` are described in section four, which begins with a general summary of the petrographic characteristics of porous and permeable Smackover strata. This is followed by a more-detailed petrophysical description of Smackover reservoirs.
A workflow for handling heterogeneous 3D models with the TOUGH2 family of codes: Applications to numerical modeling of CO 2 geological storage
Pascal Audigane; Christophe Chiaberge; Frķdķric Mathurin; Julie Lions; Gķraldine Picot-Colbeaux
This paper is addressed to the TOUGH2 user community. It presents a new tool for handling simulations run with the TOUGH2 code with specific application to CO2 geological storage. This tool is composed of separate FORTRAN subroutines (or modules) that can be run independently, using input and output files in ASCII format for TOUGH2. These modules have been developed specifically
Numerical simulations of solute transport in highly heterogeneous formations: A comparison of alternative numerical schemes
NASA Astrophysics Data System (ADS)
Boso, Francesca; Bellin, Alberto; Dumbser, Michael
We compare the accuracy of five numerical schemes in modeling transport of nonreactive and reactive solutes in porous formations with heterogeneity increasing from low (?Y2=0.2) to very high (?Y2=10). Two schemes, the Total Variation Diminishing (TVD) and the Eulerian-Lagrangian Method of Characteristics (MOC), are available in widely used packages. The other three schemes are the Random Walk Particle Tracking (RWPT), the Smoothed Particle Hydrodynamics (SPH) and a Streamline-Based (SB-FV) method, which we modified to improve its accuracy. The advective nature of the transport problem renders the numerical solution very challenging with the solutions provided by classic Eulerian methods that are plagued by numerical diffusion and spurious oscillations. Our analysis shows that TVD is severely affected by numerical diffusion, while the modified SB-FV method shows the tendency to underestimate dilution to an extent that increases with ?Y2. In addition, we show that MOC is not mass-conservative, SPH is computationally demanding and cannot handle anisotropic dispersion, while RWPT develops spurious concentration fluctuations, which can be attenuated by increasing the number of particles at the expenses of an increase of the CPU time. Moreover, we investigate the effect of uniform and non-uniform local dispersion models on the overall plume dilution. These results help to consciously choose the numerical scheme according to investigation's objectives and heterogeneity degree.
BIGFLOW: A numerical code for simulating flow in variably saturated, heterogeneous geologic media. Theory and user`s manaual, Version 1.1
Ababou, R. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France); Bagtzoglou, A.C. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses
This report documents BIGFLOW 1.1, a numerical code for simulating flow in variably saturated heterogeneous geologic media. It contains the underlying mathematical and numerical models, test problems, benchmarks, and applications of the BIGFLOW code. The BIGFLOW software package is composed of a simulation and an interactive data processing code (DATAFLOW). The simulation code solves linear and nonlinear porous media flow equations based on Darcy`s law, appropriately generalized to account for 3D, deterministic, or random heterogeneity. A modified Picard Scheme is used for linearizing unsaturated flow equations, and preconditioned iterative methods are used for solving the resulting matrix systems. The data processor (DATAFLOW) allows interactive data entry, manipulation, and analysis of 3D datasets. The report contains analyses of computational performance carried out using Cray-2 and Cray-Y/MP8 supercomputers. Benchmark tests include comparisons with other independently developed codes, such as PORFLOW and CMVSFS, and with analytical or semi-analytical solutions.
A dynamic flow simulation code benchmark study addressing the highly heterogeneous properties of the Stuttgart formation at the Ketzin pilot site
NASA Astrophysics Data System (ADS)
Kempka, Thomas; Class, Holger; G÷rke, Uwe-Jens; Norden, Ben; Kolditz, Olaf; K³hn, Michael; Walter, Lena; Wang, Wenqing; Zehner, Bj÷rn
CO2 injection at the Ketzin pilot site located in Eastern Germany (Brandenburg) about 25 km west of Berlin is undertaken since June 2008 with a scheduled total amount of about 70,000 t CO2 to be injected into the saline aquifer represented by the Stuttgart Formation at a depth of 630 m to 650 m until the end of August 2013. The Stuttgart Formation is of fluvial origin determined by high-permeablity sandstone channels embedded in a floodplain facies of low permeability indicating a highly heterogeneous distribution of reservoir properties as facies distribution, porosity and permeability relevant for dynamic flow simulations. Following the dynamic modelling activities discussed by Kempka et al. (2010), a revised geological model allowed us to history match CO2 arrival times in the observation wells and reservoir pressure with a good agreement (Martens et al., 2012). Consequently, the validated reservoir model of the Stuttgart Formation at the Ketzin pilot site enabled us to predict the development of reservoir pressure and the CO2 plume migration in the storage formation by dynamic flow simulations. A benchmark study of industrial (ECLIPSE 100 as well as ECLIPSE 300 CO2STORE and GASWAT) and scientific dynamic flow simulations codes (TOUGH2-MP/ECO2N, OpenGeoSys and DuMuX) was initiated to address and compare the simulator capabilities considering a highly complex reservoir model. Hence, our dynamic flow simulations take into account different properties of the geological model such as significant variation of porosity and permeability in the Stuttgart Formation as well as structural geological features implemented in the geological model such as seven major faults located at the top of the Ketzin anticline. Integration of the geological model into reservoir models suitable for the different dynamic flow simulators applied demonstrated that a direct conversion of reservoir model discretization between Finite Volume and Finite Element flow simulators is not feasible. Hence, the initial hexahedron meshes as applied for the ECLIPSE 100 and TOUGH2-MP/ECO2N simulations had to be converted into tetrahedron meshes to meet the convergence criteria of the Finite Element simulators DuMuX and OpenGeoSys. Our simulation results show a good agreement of reservoir pressure between all simulators, while CO2 arrival times at the observation wells strongly depend on the chosen discretization. In summary, all simulators applied are capable to address the highly complex reservoir properties present in the Stuttgart Formation at the Ketzin pilot site by dynamic flow simulations providing results of sufficient quality for prediction of future site behaviour. References Kempka, T.; K³hn, M.; Class, H.; Frykman, P.; Kopp, A.; Nielsen, C.M.; Probst, P. (2010) Modelling of CO2 arrival time at Ketzin - Part I. International Journal of Greenhouse Gas Control, Special Issue Geological CO2 Storage 4(6):1007-1015. Martens, S.; Kempka, T.; Liebscher, A.; L³th, S.; M÷ller, F.; Myrttinen, A.; Norden, B.; Schmidt-Hattenberger, C.; Zimmer, M.; K³hn, M. (2012): Europe's longest-operating on-shore CO2 storage site at Ketzin, Germany: a progress report after three years of injection. Environmental Earth Sciences. 10.1007/s12665-012-1672-5.
Geologic and hydrologic controls on coalbed methane producibility, Williams Fork Formation, Piceance Basin, Colorado
Tyler, R.; Scott, A.R.; Kaiser, W.R.; Nance, H.S.; McMurry, R.G. [Univ. of Texas, Austin, TX (United States)
Structural and depositional setting, coal rank, gas content, permeability, hydrodynamics, and reservoir heterogeneity control the producibility of coalbed methane in the Piceance Basin. The coal-rich Upper Cretaceous, Williams Fork Formation is genetically defined and regionally correlated to the genetic sequences in the Sand Wash Basin, to the north. Net coal is thickest in north-south oriented belts which accumulated on a coastal plain, behind west-east prograding shoreline sequences. Face cleats of Late Cretaceous age strike E-NE and W-NW in the southern and northern parts of the basin, respectively, normal to the Grand Hogback thrust front. Parallelism between face-cleat strike and present-day maximum horizontal stresses may enhance or inhibit coal permeability in the north and south, respectively. Geopressure and hydropressure are both present in the basin with regional hydrocarbon overpressure dominant in the central part of the basin and hydropressure limited to the basin margins. The most productive gas wells in the basin are associated with structural terraces, anticlines, and/or correspond to Cameo-Wheeler-Fairfield coal-sandstone development, reflecting basement detached thrust-faulting, fracture-enhanced permeability, and reservoir heterogeneity. Depositional heterogeneties and thrusts faults isolate coal reservoirs along the Grand Hogback from the subsurface by restricting meteoric recharge and basinward flow of ground water. An evolving coalbed methane producibility model predicts that in the Piceance Basin extraordinary coalbed methane production is precluded by low permeability and by the absence of dynamic ground-water flow.
Geologic and hydrologic controls on coalbed methane producibility, Williams Fork Formation, Piceance Basin, Colorado
Tyler, R.; Scott, A.R.; Kaiser, W.R.; Nance, H.S.; McMurry, R.G. (Univ. of Texas, Austin, TX (United States))
Structural and depositional setting, coal rank, gas content, permeability, hydrodynamics, and reservoir heterogeneity control the producibility of coalbed methane in the Piceance Basin. The coal-rich Upper Cretaceous, Williams Fork Formation is genetically defined and regionally correlated to the genetic sequences in the Sand Wash Basin, to the north. Net coal is thickest in north-south oriented belts which accumulated on a coastal plain, behind west-east prograding shoreline sequences. Face cleats of Late Cretaceous age strike E-NE and W-NW in the southern and northern parts of the basin, respectively, normal to the Grand Hogback thrust front. Parallelism between face-cleat strike and present-day maximum horizontal stresses may enhance or inhibit coal permeability in the north and south, respectively. Geopressure and hydropressure are both present in the basin with regional hydrocarbon overpressure dominant in the central part of the basin and hydropressure limited to the basin margins. The most productive gas wells in the basin are associated with structural terraces, anticlines, and/or correspond to Cameo-Wheeler-Fairfield coal-sandstone development, reflecting basement detached thrust-faulting, fracture-enhanced permeability, and reservoir heterogeneity. Depositional heterogeneties and thrusts faults isolate coal reservoirs along the Grand Hogback from the subsurface by restricting meteoric recharge and basinward flow of ground water. An evolving coalbed methane producibility model predicts that in the Piceance Basin extraordinary coalbed methane production is precluded by low permeability and by the absence of dynamic ground-water flow.
Terrestrial gamma radiation and its statistical relation with geological formation in the Mersing district, Johor, Malaysia.
Saleh, Muneer Aziz; Ramli, Ahmad Termizi; Alajeramie, Yasser; Suhairul, Hashim; Aliyu, Abubakar Sadiq; Basri, Nor Afifah
An extensive survey was carried out for gamma dose rates (GDRs) in the Mersing district, Johor, Malaysia. The average value of GDR measured in the district was found to be 140 nGy h(-1), in the range of 40-355 nGy h(-1). The mean weighted dose rate to the population, annual effective dose equivalent, collective effective dose equivalent, lifetime cancer risk were 0.836 mSv y(-1), 0.171 mSv, 1.18 ū 10(1) man Sv y(-1) and 6.98 ū 10(-4) Sv y, respectively. An isodose map was produced for the district. One way analysis of variance was used to test for differences due to different geological formations present in the Mersing District. PMID:23538891
Reducing Greenhouse Gas Emissions with Carbon Dioxide Capture and Sequestration in Deep Geological Formations
Benson, Dr. Sally [Stanford University; Cole, David R [ORNL
Carbon dioxide capture and sequestration (CCS) in deep geological formations has quickly emerged as an important option for reducing greenhouse emissions. If CCS is implemented on the scale needed for large reductions in CO2 emissions, a billion of tonnes or more of CO2 will be sequestered annually a 250 fold increase over the amount sequestered annually today. Sequestering these large volumes will require a strong scientific foundation of the coupled hydrological-geochemical-geomechanical processes that govern the long term fate of CO2 in the subsurface. Methods to characterize and select sequestration sites, subsurface engineering to optimize performance and cost, safe operations, monitoring technology, remediation methods, regulatory oversight, and an institutional approach for managing long term liability are also needed.
Sudbury project (University of Muenster-Ontario Geological Survey): Petrology, chemistry, and origin of breccia formations
NASA Technical Reports Server (NTRS)
Stoeffler, D.; Deutsch, A.; Avermann, M.; Brockmeyer, P.; Lakomy, R.; Mueller-Mohr, V.
Within the Sudbury Project of the University of Muenster and the Ontario Geological Survey special emphasis was put on the breccia formations exposed at the Sudbury structure (SS) because of their crucial role for the impact hypothesis. They were mapped and sampled in selected areas of the north, east, and south ranges of the SS. The relative stratigraphic positions of these units are summarized. Selected samples were analyzed by optical microscopy, SEM, microprobe, XRF and INAA, Rb-Sr and SM-Nd-isotope geochemistry, and carbon isotope analysis. The results of petrographic and chemical analysis for those stratigraphic units that were considered the main structural elements of a large impact basin are summarized.
Formation drillability prediction based on multi-source information fusion
Hai Ma
Various information sources in petroleum exploration and exploitation, such as seismic, well logging, mud logging and drilling data, are the comprehensive reflection of the same geological body underground and have a strong correlation with each other. A multi-dimensional heterogeneous space model is presented for a range of geological characteristic parameters prediction, such as formation pore pressure, formation drillability, rock strength,
Development of a novel heterogeneous flow reactor -- Soot formation and nanoparticle catalysis
NASA Astrophysics Data System (ADS)
Camacho, Joaquin
The development of novel experimental approaches to investigate fundamental surface kinetics is presented. Specifically, fundamental soot formation and surface catalysis processes are examined in isolation from other competing processes. In terms of soot formation, two experimental techniques are presented: the Burner Stabilized Stagnation (BSS) flame configuration is extended to isolate the effect of the parent fuel structure on soot formation and the fundamental rate of surface oxidation for nascent soot is measured in a novel aerosol flow reactor. In terms of nanoparticles, the physical and chemical properties of freely suspended nanoparticles are investigated in a novel aerosol flow reactor for methane oxidation catalyzed by palladium. The role of parent fuel structure within soot formation is examined by following the time resolved formation nascent soot from the onset of nucleation to later growth stages for premixed BSS flames. Specifically, the evolution of the detailed particle size distribution function (PSDF) is compared for butanol, butane and C6 hydrocarbons in two separate studies where the C/O ratio and temperature are fixed. Under this constraint, the overall sooting process were comparable as evidenced by similar time resolved bimodal PSDF. However, the nucleation time and the persistence of nucleation with time is strongly dependent upon the structure of the parent fuel. For the C6 hydrocarbon fuels, the fastest onset of soot nucleation is observed in cyclohexane and benzene flames and this may be due to significant aromatic formation that is predicted in the pre-flame region. In addition, the evolution of the PSDF shows that nucleation ends sooner in cylclohexane and benzene flames and this may be due to relatively quick depletion of soot precursors such as acetylene and benzene. Interestingly,within the butanol fuels studied the effect of the branched chain in i-butanol and i-butane was more significant than the presence of fuel bound oxygen. A numerical analysis of the gas-phase chemistry for butanol and butane indicates the fuel structure effect is largely exhibited in the relative importance of C2 versus C3 intermediate species formed during the initial stage of fuel breakdown. Oxidation kinetics of soot are typically measured with carbon black or well aged soot as substrates. The soot surface is also assumed to be graphitic in theoretical soot oxidation rate calculations. However, recent experimental and theoretical studies show that nascent soot can have structures and surface composition drastically different from mature, graphitized soot. In the current study, oxidation of nascent soot by O2 was observed at T= 950 and 1000K for oxygen concentrations ranging from 1000 to 7800 ppm in a laminar aerosol flow reactor at ambient pressure. Oxidation behavior of primary particles (Dp < 20 nm) of nascent soot from a premixed BSS ethylene flame was observed by tracking the shift in the particle size distribution function (PSDF) under a given residence time. The measured rate of the surface reaction ranges from 1x106 -- 3x10 6 g/cm2s for nascent soot. The rate of oxidation observed at the given conditions is an order of magnitude faster than predicted by the classical Nagle Strickland-Constable (NSC) correlations derived from graphite oxidation. Heterogeneous surface reaction rates are highly sensitive to the surface composition. Thus the faster rate of surface reaction by the nascent soot observed currently suggests that the surface composition of nascent soot is more reactive than the conventional graphite surface. Catalytic activity in reacting flow laden with suspended nanoparticle catalyst is measured in a novel aerosol flow reactor. Similar to conventional gas phase kinetics, heterogeneous reactions are the product of collisions between the particle surface and surrounding gas. However, particles below 10 nm in diameter are in a transition region where collisions do not always result in perfectly elastic scattering. The inelastic scattering provides more opportunities for reaction to occur than
Heterogeneity in a Low-Permeability Formation or Non-Ideal Testing Conditions?
NASA Astrophysics Data System (ADS)
Mishra, S.; Deeds, N. E.; Pickens, J. F.; Distinguin, M.; Delay, J.
Hydraulic testing in packer-isolated wellbore intervals in low-permeability formations is often complicated by non-ideal conditions such as thermal expansion of fluid in the test interval, packer squeeze and borehole closure. Such processes lead to fluid accumulation and pressurization within the wellbore during shut-in, and can exert significant effects on the measured borehole pressure response. Unless these conditions are taken into account during test interpretation, it is possible to make inappropriate conclusions regarding formation heterogeneity (e.g., lateral permeability variations) and/or static pressure levels. We have developed a lumped parameter modeling approach by treating the combined effect of these processes as the equivalent of an additional volume of fluid accumulating within the test interval (in addition to the nominal test-interval volume at the time of shut-in). We postulate that the rate of fluid accumulation can be treated in a simple manner as a constant value for the duration of the test. Thus, the fluid accumulation problem can be recast as the equivalent of a constant injection rate into the packed-off volume within the borehole. We show how this surrogate injection rate can be estimated from the measured pressure data by exploiting the analogy between the pressure response during borehole storage dominated conditions and that of a line-source well with an exponentially varying flow rate. Shut-in test sequences (i.e., shut-in period prior to initiation of a pressure pulse test and shut-in period(s) during pulse test(s)) can then be analyzed as effective constant-rate injection periods. The methodology is demonstrated using data from a recent series of hydraulic tests conducted in support of site characterization activities by ANDRA, the French radioactive waste management agency. In many of these tests, the measured pressure response was fitted to a 2-zone radially composite system model. Although the fit was visually excellent, static pressure estimates were found to be significantly different than those obtained from long-term pressure monitoring data from permanently installed borehole pressure gauges that use wireless telemetry for data transmission. These special tools (called EPG tools) provide the highest quality monitoring data for defining true undisturbed formation pressures in very low-permeability formations. In this study, the hydraulic-test data were reanalyzed using the lumped parameter modeling approach with a single-zone homogeneous model constrained to the static pressure bounds indicated by the EPG data. The single-zone analysis yields visual fits comparable to those from the 2-zone radially composite model, and formation parameters that are statistically much more robust (i.e., they do not suffer from over-parameterization and poor parameter identifiability as do the parameter estimates from the 2-zone conceptualization). We conclude that the effects of non-ideal testing conditions can be mistaken as indicators of formational heterogeneities.
Stratigraphic hierarchy and cycle stacking, facies distribution, and Interwell-Scale heterogeneity: Grayburg Formation, New Mexico
Barnaby, R.J.; Ward, W. B. [Univ. of Texas, Austin, TX (United States)
The Grayburg Formation (middle Guadaluplan) of southeastern New Mexico is a mixed carbonate-siliciclastic succession that represents predominantly shallow water sedimentation on the Northwest Shelf of the Delaware Basin. Exceptional Grayburg outcrops in the Brokeoff Mountains permit high-resolution correlation and mapping of interwell-scale facies complexity both along depositional dip and across strike. Three orders of stratigraphic hierarchy are recognized using vertical facies successions and transgressive-regressive relationships expressed along a dip cross section. This stratigraphic organization cannot be fully defined from a vertical section. Cycles (3-30 ft thick) are the smallest-scale, upward-shoaling facies successions that can be correlated across facies tracts and constitute the basic chronostratigraphic unit. Cycles are organized into transgressive-regressive cycle sets (15-40 ft thick). High-frequency sequences (100-160 ft thick) are unconformity-bound successions composed of 10 to 20 cycles arranged into transgressive and highstand systems tracts. One-dimensional cycle thickness stacking patterns do not reflect the long-term accommodation trends imposed by high-frequency sequences because most cycles did not fully aggrade to sea level. Interwell-scale heterogeneity (hundreds of ft) is high in transgressive ooid grainstones, which formed dip-elongate tidal channels and shoals. Highstand ooid grainstones formed strike-elongate shoals that are laterally continuous along dip and across strike (thousands of feet) due to stacking and amalgamation of grainstone bodies in an accommodation-limited highstand setting. The well-defined relationship between stratigraphic hierarchy and facies composition and heterogeneity can be used to improve correlations and better predict lateral dimensions of reservoir facies.
Stratigraphic hierarchy and cycle stacking, facies distribution, and Interwell-Scale heterogeneity: Grayburg Formation, New Mexico
Barnaby, R.J.; Ward, W. B. (Univ. of Texas, Austin, TX (United States))
The Grayburg Formation (middle Guadaluplan) of southeastern New Mexico is a mixed carbonate-siliciclastic succession that represents predominantly shallow water sedimentation on the Northwest Shelf of the Delaware Basin. Exceptional Grayburg outcrops in the Brokeoff Mountains permit high-resolution correlation and mapping of interwell-scale facies complexity both along depositional dip and across strike. Three orders of stratigraphic hierarchy are recognized using vertical facies successions and transgressive-regressive relationships expressed along a dip cross section. This stratigraphic organization cannot be fully defined from a vertical section. Cycles (3-30 ft thick) are the smallest-scale, upward-shoaling facies successions that can be correlated across facies tracts and constitute the basic chronostratigraphic unit. Cycles are organized into transgressive-regressive cycle sets (15-40 ft thick). High-frequency sequences (100-160 ft thick) are unconformity-bound successions composed of 10 to 20 cycles arranged into transgressive and highstand systems tracts. One-dimensional cycle thickness stacking patterns do not reflect the long-term accommodation trends imposed by high-frequency sequences because most cycles did not fully aggrade to sea level. Interwell-scale heterogeneity (hundreds of ft) is high in transgressive ooid grainstones, which formed dip-elongate tidal channels and shoals. Highstand ooid grainstones formed strike-elongate shoals that are laterally continuous along dip and across strike (thousands of feet) due to stacking and amalgamation of grainstone bodies in an accommodation-limited highstand setting. The well-defined relationship between stratigraphic hierarchy and facies composition and heterogeneity can be used to improve correlations and better predict lateral dimensions of reservoir facies.
3rd hand smoking; heterogeneous oxidation of nicotine and secondary aerosol formation in the indoor environment
NASA Astrophysics Data System (ADS)
Petrick, Lauren; Dubowski, Yael
Tobacco smoking is well known as a significant source of primary indoor air pollutants. However, only recently has it been recognized that the impact of Tobacco smoking may continue even after the cigarette has been extinguished (i.e., third hand smoke) due to the effect of indoor surfaces. These surfaces may affect the fate of tobacco smoke in the form of secondary reactions and pollutants, including secondary organic aerosol (SOA) formation. Fourier Transform Infrared spectrometry with Attenuated Total Reflection (FTIR-ATR) in tandem with a Scanning Mobility Particle Sizing (SMPS) system was used to monitor the ozonation of cellulose sorbed nicotine and resulting SOA formation. SOA formation began at onset of ozone introduction ([O3] = 60 ▒ 5 ppb) with a size distribution of dp ? 25 nm, and was determined to be a result of heterogeneous reaction (opposed to homogeneous). SOA yield from reacted surface nicotine was on the order of 10 %. Simultaneous to SOA monitoring, FTIR-ATR spectra showed surface changes in the nicotine film as the reaction progressed, revealing a pseudo first-order surface reaction rate of 0.0026 ▒ 0.0008 min-1. Identified surface oxidation products included: cotinine, myosmine, methylnicotinamide and nicotyrine. Surface reaction rate was found to be partially inhibited at high relative humidity. Given the toxicity of some of the identified products (e.g., cotinine has shown potential mutagenicity and teratogenicity) and that small particles may contribute to adverse health effects, the present study indicates that exposure to 3rd hand smoke ozonation products may pose additional health risks.
Assessment of potential radionuclide transport in site-specific geologic formations
Dosch, R.G.
Associated with the development of deep, geologic repositories for nuclear waste isolation is a need for safety assessments of the potential for nuclide migration. Frequently used in estimating migration rates is a parameter generally known as a distribution coefficient, K/sub d/, which describes the distribution of a radionuclide between a solid (rock) and a liquid (groundwater) phase. This report is intended to emphasize that the use of K/sub d/ must be coupled with a knowledge of the geology and release scenarios applicable to a repository. Selected K/sub d/ values involving rock samples from groundwater/brine simulants typical of two potential repository sites, WIPP and NTS, are used to illustrate this concern. Experimental parameters used in K/sub d/ measurements including nuclide concentration, site sampling/rock composition, and liquid-to-solid ratios are discussed. The solubility of U(VI) in WIPP brine/groundwater was addressed in order to assess the potential contribution of this phenomena to K/sub d/ values. Understanding mehanisms of sorption of radionuclides on rocks would lead to a better predictive capability. Sorption is attributed to the presence of trace constituents (often unidentified) in rocks. An attempt was made to determine if this applied to WIPP dolomite rocks by comparing sorption behavior of the natural material with that of a synthetic dolomite prepared in the laboratory with reagent grade chemicals. The results were inconclusive. The results of a study of Tc sorption by an argillite sample from the Calico Hills formation at NTS under ambient laboratory conditions were more conclusive. The Tc sorption was found to be associated with elemental carbon. Available evidence points to a reduction mechanism leading to the apparent sorption of Tc on the solid phase.
Supercritical fluid behavior at nanoscale interfaces: implications for CO2 sequestration in geologic formations
Cole, David R [ORNL; Chialvo, Ariel A [ORNL; Rother, Gernot [ORNL; Vlcek, L. [Vanderbilt University; Cummings, Peter T [ORNL
Injection of CO2 into subsurface geologic formations has been identified as a key strategy for mitigating the impact of anthropogenic emissions of CO2. A key aspect of this process is the prevention of leakage from the host formation by an effective cap or seal rock which has low porosity and permeability characteristics. Shales comprise the majority of cap rocks encountered in subsurface injection sites with pore sizes typically less than 100 nm and whose surface chemistries are dominated by quartz (SiO2) and clays. We report the behavior of pure CO2 interacting with simple substrates, i.e. SiO2 and mica, that act as proxies for more complex mineralogical systems. Modeling of small-angle neutron scattering (SANS) data taken from CO2- silica aerogel (95% porosity; 6 nm pores) interactions indicates the presence of fluid depletion for conditions above the critical density. A theoretical framework, i.e. integral equation approximation (IEA), is presented that describes the fundamental behavior of near-critical adsorption onto a non-confining substrate that is consistent with SANS experimental results. Structural and dynamic behavior for supercritical CO2 interaction in K-mica slit pores was assessed by classical molecular dynamics (CMD). These results indicate the development of distinct layers of CO2 within slit pores, reduced mobility by one to two orders of magnitudes compared to bulk CO2 depending on pore size and formation of bonds between CO2 oxygens and H from mica hydroxyls. Analysis of simple, well-characterized fluid-substrate systems can provide details on the thermodynamic, structural and dynamic properties of CO2 at conditions relevant to sequestration.
Geology of the Molina Member of the Wasatch Formation, Piceance Basin, Colorado
Lorenz, J. [Sandia National Labs., Albuquerque, NM (United States); Nadon, G. [Ohio Univ., Athens, OH (United States); LaFreniere, L. [FD Services Inc., Casper, WY (United States)
The Molina Member of the Wasatch Formation has been cored in order to assess the presence/absence and character of microbial communities in the deep subsurface. Geological study of the Molina Member was undertaken in support of the microbiological tasks of this project, for the purposes of characterizing the host strata and of assessing the potential for post-depositional introduction of microbes into the strata. The Molina Member comprises a sandy fluvial unit within a formation dominated by mudstones. Sandy to conglomeratic deposits of braided and meandering fluvial systems are present on the western and eastern margins of the basin respectively, although the physical and temporal equivalence of these systems cannot be proven. Distal braided facies of planar-horizontal bedded sandstones are recognized on the western margin of the basin. Natural fractures are present in all Molina sandstones, commonly as apparent shear pairs. Core from the 1-M-18 well contains natural fractures similar to those found in outcrops, and has sedimentological affinities to the meandering systems of the eastern margin of the basin. The hydrologic framework of the Molina, and thus any potential post-depositional introduction of microbes into the formation, should have been controlled by approximately east-west flow through the natural fracture system, the geometries and extent of the sandstones in which the fractures occur, and hydraulic gradient. Migration to the well site, from outcropping recharge areas at the edge of the basin, could have started as early as 40 million years ago if the cored strata are connected to the eastern sedimentary system.
Geologically Controlled Isotope-Time Patterns Reveal Early Differentiation and Crust Formation Processes
NASA Astrophysics Data System (ADS)
Bennett, V. C.; Nutman, A. P.
The mechanisms of continental crust production and evolution in the early Earth remain controversial, as are questions of the relative roles of early differentiation versus subsequent tectonic procssing in creating Earth's chemical signatures. Here we present geologic observations integrated with whole rock major, trace element and Sm-Nd isotopic signatures and combined with U-Pb and Lu-Hf isotopic compositions of zircon populations from the same rocks, from the most extensive early rock record comprising the 3.9 Ga to 3.6 Ga terranes of southwest Greenland. These data reveal repeated patterns of formation of juvenile TTG crust and associated mafic and ultramafic rocks in convergent margin settings followed by formation of more evolved granites [1]. Our new zircon Lu-Hf data from rare 3.6-3.7 Ga tonalites within the Itsaq Gneiss Complex, obtained from single component, non-migmatitic gneisses with simple zircon populations, limited within sample Hf isotopic variability and accurate U-Pb ages, now document extraction of juvenile tonalites from a near chondritic mantle source between 3.9 Ga and 3.6 Ga. The more evolved, granitic rocks in each area show slightly negative initial ?Hf in accord with crustal reworking of the older (3.8-3.9 Ga) gniesses. There is no evidence for Hadean material in the sources of the granitoids. The Hf isotope-time patterns are consistent with juvenile crust production from a mantle source that experienced only modest amounts of prior crustal extraction. They are distinct from those predicted by reprocessing of an enriched Hadean mafic crust, as has been proposed for this region [2] and for the source of the Hadean Jack Hills zircons [3]. The well-documented, time decreasing, positive 142Nd anomalies [e.g., 4] from these rocks are further evidence of crustal derivation from a convecting mantle source, rather than reworking of an enriched mafic lithosphere. The 143Nd isotopic -time patterns are more complex, reflecting the interplay between early Sm/Nd fractionation processes as required by the 142Nd data, juvenile crustal growth and in some cases geologic disturbance of the whole rock Sm-Nd system. [1] Nutman, et al, (2013) Amer. Jour. Sci. 313, 877-911. [2] Naeraa et al.. (2012) Nature 485, 627-631. [3] Kemp et al., (2010) EPSL 296, 45-56. [4] Bennett et al., (20070 Science 318, 1907.
Heterogeneous chemistry of glyoxal on acidic solutions. An oligomerization pathway for secondary organic aerosol formation.
Gomez, Mario E; Lin, Yun; Guo, Song; Zhang, Renyi
The heterogeneous chemistry of glyoxal on sulfuric acid surfaces has been investigated at various acid concentrations and temperatures, utilizing a low-pressure fast flow laminar reactor coupled to an ion drift-chemical ionization mass spectrometer (ID-CIMS). The uptake coefficient (?) of glyoxal ranges from (1.2 ▒ 0.06) ū 10(-2) to (2.5 ▒ 0.01) ū 10(-3) for 60-93 wt % H2SO4 at 253-273 K. The effective Henry's Law constant (H*) ranges from (98.9 ▒ 4.9) ū 10(5) to (1.6 ▒ 0.1) ū 10(5) M atm(-1) for 60-93 wt % at 263-273 K. Both the uptake coefficient and Henry's Law constant increase with decreasing acid concentration and temperature. Our results reveal a reaction mechanism of hydration followed by oligomerization for glyoxal on acidic media, indicating an efficient aqueous reaction of glyoxal on hygroscopic particles leading to secondary organic aerosol formation. PMID:25369518
Source/Sink Matching for U.S. Ethanol Plants and Candidate Deep Geologic Carbon Dioxide Storage Formations
Dahowski, Robert T.; Dooley, James J.
This report presents data on the 140 existing and 74 planned ethanol production facilities and their proximity to candidate deep geologic storage formations. Half of the existing ethanol plants and 64% of the planned units sit directly atop a candidate geologic storage reservoir. While 70% of the existing and 97% of the planned units are within 100 miles of at least one candidate deep geologic storage reservoir. As a percent of the total CO2 emissions from these facilities, 92% of the exiting units CO2 and 97% of the planned units CO2 emissions are accounted for by facilities that are within 100 miles of at least one potential CO2 storage reservoir.
Nuclear Waste Disposal in Deep Geological Formations: What are the Major Remaining Scientific Issues?
Toulhoat, Pierre [Institut des Sciences Analytiques, Universite de Lyon, 43 avenue du 11 novembre 1918, Villeurbanne, 69622 (France); Scientific Direction, INERIS, Parc Technologique ALATA, BP2, Verneuil-en-Halatte, 60550, (France)
For more than thirty years, considerable efforts have been carried out in order to evaluate the possibility of disposing of high level wastes in deep geological formations. Different rock types have been examined, such as water-under-saturated tuffs (USA), granites or crystalline rocks (Canada, Sweden, and Finland), clays (France, Belgium, and Switzerland), rock-salt (Germany). Deep clays and granites, (provided that the most fractured zones are avoided in the second case) are considered to fulfill most allocated functions, either on short term (reversibility) or long term. Chemically reducing conditions favor the immobilization of actinides and most fission products by precipitation, co-precipitation and sorption. If oxidizing conditions prevail, the safety demonstration will mostly rely on the performance of artificial confinement systems. Rock-salt offers limited performance considering the issue of reversibility, which is now perceived as essential, mostly for ethical and sociological reasons. However, several issues would deserve additional research programs, and as a first priority, a clear description of time/space succession of processes during the evolution of the repository. This will allow a better representation of coupled processes in performance assessment, such as the influence of gases (H{sub 2}) generated by corrosion, on the long term dynamics of the re-saturation. Geochemical interactions between the host formation and the engineered systems (packages + barriers) are still insufficiently described. Additional gains in performance could be obtained when taking into account processes such as isotopic exchange. Imaginative solutions, employing ceramic- carbon composite materials could be proposed to replace heavy and gas-generating overpacks, or to accommodate the small but probably significant amount of 'ultimate' wastes that will be inevitably produced by Generation IV reactor systems. (author)
A Fundamental Study of Convective Mixing of CO2 in Heterogeneous Geologic Media using Surrogate Fluids and Numerical Modeling
experiments. These simulations are carried out for the fluids propylene glycol (PG) and water. It is assumed the fingering behavior. A second set of experiments was conducted for layered systems to study the effects and diffusive flux ratio. Future Work: Studying groundwater flow velocity, complex heterogeneity, effective
Microbial characterization of basalt formation waters targeted for geological carbon sequestration.
Lavalleur, Heather J; Colwell, Frederick S
Geological carbon sequestration in basalts is a promising solution to mitigate carbon emissions into the Earth's atmosphere. The Wallula pilot well in Eastern Washington State, USA provides an opportunity to investigate how native microbial communities in basalts are affected by the injection of supercritical carbon dioxide into deep, alkaline formation waters of the Columbia River Basalt Group. Our objective was to characterize the microbial communities at five depth intervals in the Wallula pilot well prior to CO2 injection to establish a baseline community for comparison after the CO2 is injected. Microbial communities were examined using quantitative polymerase chain reaction to enumerate bacterial cells and 454 pyrosequencing to compare and contrast the diversity of the native microbial communities. The deepest depth sampled contained the greatest amount of bacterial biomass, as well as the highest bacterial diversity. The shallowest depth sampled harbored the greatest archaeal diversity. Pyrosequencing revealed the well to be dominated by the Proteobacteria, Firmicutes, and Actinobacteria, with microorganisms related to hydrogen oxidizers (Hydrogenophaga), methylotrophs (Methylotenera), methanotrophs (Methylomonas), iron reducers (Geoalkalibacter), sulfur oxidizers (Thiovirga), and methanogens (Methermicocccus). Thus, the Wallula pilot well is composed of a unique microbial community in which hydrogen and single-carbon compounds may play a significant role in sustaining the deep biosphere. PMID:23418786
Geologic reservoir model for the Triassic Doig Formation, northeast British Columbia, Canada
Moslow, T.F. (Univ. of Alberta, Edmonton (Canada)); Munroe, H.D. (International Geoscience Consulting Ltd., Calgary, Alberta (Canada))
A subsurface investigation of the mid-Triassic Doig formation in northeastern British Columbia documented two main reservoir facies. Both are a product of mass movement and sediment gravity flow processes on a progradational, tectonically active continental shelf margin. Substrate instability was likely a product of sediment loading, perhaps in concert with seismic activity. Sedimentary facies and reservoir parameters were determined from analysis of approximately 150 cores and 900 well logs. Laterally discontinuous Doig sandstones are up to 60 m thick and trend northeasterly within the study area. The main reservoir facies are incised density flow deposits and laterally extensive slump deposits. Reservoir quality within these sands is extremely variable with porosity ranging from less than 5% to 15%. In core, these deposits consist of moderately well sorted, very fine grained sandstones with no vertical grain size variation. The best production to date is in the Buick Creek field with initial flows of 346 BOPD. The slump deposits are thinner and tend to be more elongate parallel to paleoshoreline. These sands were subject to some wave or current reworking. Modern analogs where similar processes and products of deposition are known to occur include the Gulf of Alaska continental shelf and the Fraser River Delta slope. Doig sandstones usually are enclosed in fine-grained shelf deposits that provide a good stratigraphic trapping mechanism. Successful development of Doig reservoirs must incorporate geologic modes that assist in understanding the complex and highly variable reservoir quality of sandstones units.
The Effect of Homogeneous vs. Heterogeneous Matching-Item Format on Test Performance and Reliability.
ERIC Educational Resources Information Center
Allison, Donald E.
Reports that no significant difference in reliability appeared between a heterogeneous and a homogeneous form of the same general science matching-item test administered to 316 sixth-grade students but that scores on the heterogeneous form of the test were higher, independent of the examinee's sex or intelligence. (SB)
Capacity investigation of brine-bearing sands of the Fwwm formation for geologic sequestration of CO{sub 2}
Doughty, Christine; Pruess, Karsten; Benson, Sally M.; Hovorka, Susan D.; Knox, Paul R.; Green, Christopher T.
The capacity of fluvial brine-bearing formations to sequester CO{sub 2} is investigated using numerical simulations of CO{sub 2} injection and storage. Capacity is defined as the volume fraction of the subsurface available for CO{sub 2} storage and is conceptualized as a product of factors that account for two-phase flow and transport processes, formation geometry, formation heterogeneity, and formation porosity. The space and time domains used to define capacity must be chosen with care to obtain meaningful results, especially when comparing different authors' work. Physical factors that impact capacity include permeability anisotropy and relative permeability to CO{sub 2}, brine/CO{sub 2} density and viscosity ratios, the shape of the trapping structure, formation porosity and the presence of low-permeability layering.
FOREWORD: Heterogenous nucleation and microstructure formation---a scale- and system-bridging approach Heterogenous nucleation and microstructure formation---a scale- and system-bridging approach
H. Emmerich
Scope and aim of this volume. Nucleation and initial microstructure formation play an important role in almost all aspects of materials science [1-5]. The relevance of the prediction and control of nucleation and the subsequent microstructure formation is fully accepted across many areas of modern surface and materials science and technology. One reason is that a large range of material
The Oil Game: Problem-based learning exercise in an Environmental Geology lecture-format class
NSDL National Science Digital Library
David Voorhees
This is an active engagement exercise as a capstone exercise in a unit on energy in an Environmental Geology class of non-science majors combining a 'field-based' simulation and 'office-based' geological modeling. It uses readily available supplies and easily constructed equipment that can take 1 or 2 class meetings.
A geological and engineering reservoir characterization of the Caballos Formation (Cretaceous), Puerto Colon field Putumayo basin, ColombiaĀ
Ruiz Castellanos, Hector
is the national oil company. The field produces I'rom the Cretaceous sandstones of the Caballos Formation and is estimated to contain approximately 90 million bbl of oil in place. The development of the field is not complete, and plans are currently undetway... to determine the extension of the reservoir. Enhanced oil recovery activities are also being considered. A integrated reservoir characterization technique is used to integrate the geological, engineering, and reservoir performance data to describe...
Effect of pattern formation on C and N turnover heterogeneity in initial soils
NASA Astrophysics Data System (ADS)
Schaaf, Wolfgang; Zimmermann, Claudia
The formation of vegetation patterns and hydrological processes, among others, result in soil heterogeneity in newly exposed land surfaces. We studied the effect of these developling structures on carbon and nitrogen trunover in soils of the artificial catchment Chicken Creek (Schaaf et al. 2011, 2012). Substrates with different physical and geochemical properties in combination with different labelled plant litter materials were studied in a microcosm experiment over a period of 80 weeks. Main objectives of the microcosm experiment were to determine the transformation processes of C and N from litter decomposition within the gaseous, liquid and solid phase, the interaction with mineral surfaces and its role for the establishment of biogeochemical cycles. The microcosm experiments were established in a climate chamber at constant 10 ░C. In total, 48 soil columns (diameter: 14.4 cm; height: 30 cm) were filled with two different quaternary substrates (sand and loamy sand) representing the textural variation within the catchment at a bulk density of 1.4-1.5 g cm-3. The columns were automatically irrigated with artificial rainwater four times a day with 6.6 ml each (corresponding to 600 mm yr-1). The gaseous phase in the headspace of the microcosms was analyzed continuously for CO2 and N2O concentrations. C and N transformation processes were studied using 13C and 15N labelled litter of two different plant species occurring at the catchment (Lotus corniculatus, Calamagrostis epigejos) that was incorporated into the microcosm surface. By including litter from species with wide distribution within the catchment and soil substrates representing the main variation types of the sediments used for catchment construction we were able to characterize the general function of these sub-patches within the catchment with respect to litter decomposition, soil solution composition, DOC and nutrient leaching, and impact on the mineral soil phase. The results suggest that initial differences in substrate composition in combination with invading vegetation leads to the development of patterns with different biogeochemical process intensities within the catchment. These patterns are not mere additive effects of substrates plus litter, but reflect differences in element cycling. Schaaf, W., Bens, O., Fischer, A., Gerke, H.H., Gerwin, W., Gr³newald, U., Hollõnder, H.M., K÷gel-Knabner, I., Mutz, M., Schloter, M., Schulin, R., Veste, M., Winter, S. & H³ttl, R.F. (2011): Patterns and processes of initial terrestrial ecosystem development. J Plant Nutr Soil Sci, 174, 229-239. Schaaf, W., Elmer, M., Fischer, A., Gerwin, W., Nenov, R., Pretzsch, H., Seifert, S., Winter, S., Zaplata, M. (2012): Monitoring the formation of structures and patterns during initial development of an artificial catchment. Environmental Monitoring and Assessment. doi: 10.1007/s10661-012-2998-x.
Challenges in conditioning a stochastic geological model of a heterogeneous glacial aquifer to a comprehensive soft dataset
NASA Astrophysics Data System (ADS)
Koch, J.; He, X.; Jensen, K. H.; Refsgaard, J. C.
In traditional hydrogeological investigations, one geological model is often used based on subjective interpretations and sparse data availability. This deterministic approach usually does not account for any uncertainties. Stochastic simulation methods address this problem and can capture the geological structure uncertainty. In this study the geostatistical software TProGS is utilized to simulate an ensemble of realizations for a binary (sand/clay) hydrofacies model in the Norsminde catchment, Denmark. TProGS can incorporate soft data, which represent the associated level of uncertainty. High density (20 m ū 20 m ū 2 m) airborne geophysical data (SkyTEM) and categorized borehole data are utilized to define the model of spatial variability and for soft conditioning the TProGS simulations. The category probabilities for the SkyTEM dataset are derived from a histogram probability matching method, where resistivity is paired with the corresponding lithology from the categorized borehole data. A novelty of this study is the incorporation of two distinct datasources into the stochastic modeling process that represents two extremes of the conditioning density spectrum; sparse borehole data and abundant SkyTEM data. The high density of spatially correlated SkyTEM data lead to very deterministic simulation results. This is caused by overconditioning and addressed by a work around utilizing a resampling (thinning) of the dataset. In the case of abundant conditioning data it is shown that TProGS is capable of reproducing non-stationary trends. The stochastic realizations are validated by five performance criteria: (1) sand proportion, (2) mean length, (3) geobody connectivity, (4) facies probability distribution and (5) facies probability - resistivity bias. As conclusion, a stochastically generated set of realizations soft conditioned to 200 m moving sampling of geophysical data performs most satisfying when balancing the five performance criteria and can be used in subsequent hydrogeological flow modeling to address the predictive uncertainty originated from the geological structure uncertainty.
Truncated plurigaussian simulations to characterize aquifer heterogeneity.
Mariethoz, Grķgoire; Renard, Philippe; Cornaton, Fabien; Jaquet, Olivier
Integrating geological concepts, such as relative positions and proportions of the different lithofacies, is of highest importance in order to render realistic geological patterns. The truncated plurigaussian simulation method provides a way of using both local and conceptual geological information to infer the distributions of the facies and then those of hydraulic parameters. The method (Le Loc'h and Galli 1994) is based on the idea of truncating at least two underlying multi-Gaussian simulations in order to create maps of categorical variable. In this article, we show how this technique can be used to assess contaminant migration in highly heterogeneous media. We illustrate its application on the biggest contaminated site of Switzerland. It consists of a contaminant plume located in the lower fresh water Molasse on the western Swiss Plateau. The highly heterogeneous character of this formation calls for efficient stochastic methods in order to characterize transport processes. PMID:18793207
Evidence for Regional Basin Formation in Early Post-Tessera Venus History: Geology of the Lavinia Planitia Area (V55)
NASA Technical Reports Server (NTRS)
Head, J. W.; Ivanov, M. A.
On Venus, global topography shows the presence of highs and lows including regional highly deformed plateaus (tesserae), broad rifted volcanic rises, linear lows flanking uplands, and more equidimensional lowlands (e.g. Lavinia and Atalanta planitiae) Each of these terrain types on Venus has relatively distinctive characteristics, but origins are uncertain in terms of mode of formation, time of formation, and potential evolutionary links. There is a high level of uncertainty about the formation and evolution of lowlands on Venus. We have undertaken the mapping of a specific lowlands region of Venus to address several of these major questions. Using geologic mapping we have tried to establish: What is the sequence of events in the formation and evolution of large-scale equidimensional basins on Venus? When do the compressional features typical of basin interiors occur? What is the total volume of lava that occurs in the basins and is this similar to other non-basin areas? How much subsidence and downwarping has occurred after the last major plains units? WE have undertaken an analysis of the geology of the V55 Lavinia Planitia quadrangle in order to address many of these issues and we report on the results here.
Challenges in conditioning a stochastic geological model of a heterogeneous glacial aquifer to a comprehensive soft data set
NASA Astrophysics Data System (ADS)
Koch, J.; He, X.; Jensen, K. H.; Refsgaard, J. C.
In traditional hydrogeological investigations, one geological model is often used based on subjective interpretations and sparse data availability. This deterministic approach usually does not account for any uncertainties. Stochastic simulation methods address this problem and can capture the geological structure uncertainty. In this study the geostatistical software TProGS is utilized to simulate an ensemble of realizations for a binary (sand/clay) hydrofacies model in the Norsminde catchment, Denmark. TProGS can incorporate soft data, which represent the associated level of uncertainty. High-density (20 m ū 20 m ū 2 m) airborne geophysical data (SkyTEM) and categorized borehole data are utilized to define the model of spatial variability in horizontal and vertical direction, respectively, and both are used for soft conditioning of the TProGS simulations. The category probabilities for the SkyTEM data set are derived from a histogram probability matching method, where resistivity is paired with the corresponding lithology from the categorized borehole data. This study integrates two distinct data sources into the stochastic modeling process that represent two extremes of the conditioning density spectrum: sparse borehole data and abundant SkyTEM data. In the latter the data have a strong spatial correlation caused by its high data density, which triggers the problem of overconditioning. This problem is addressed by a work-around utilizing a sampling/decimation of the data set, with the aim to reduce the spatial correlation of the conditioning data set. In the case of abundant conditioning data, it is shown that TProGS is capable of reproducing non-stationary trends. The stochastic realizations are validated by five performance criteria: (1) sand proportion, (2) mean length, (3) geobody connectivity, (4) facies probability distribution and (5) facies probability-resistivity bias. In conclusion, a stochastically generated set of realizations soft-conditioned to 200 m moving sampling of geophysical data performs most satisfactorily when balancing the five performance criteria. The ensemble can be used in subsequent hydrogeological flow modeling to address the predictive uncertainty originating from the geological structure uncertainty.
Effect of crustal heterogeneities and effective rock strength on the formation of HP and UHP rocks.
NASA Astrophysics Data System (ADS)
Reuber, Georg; Kaus, Boris; Schmalholz, Stefan; White, Richard
The formation of high pressure and ultra-high pressure rocks has been controversially discussed in recent years. Most existing petrological interpretations assume that pressure in the Earth is lithostatic and therefore HP and UHP rocks have to come from great depth, which usually involves going down a subduction channel and being exhumed again. Yet, an alternative explanation points out that pressure in the lithosphere is often non-lithostatic and can be either smaller or larger than lithostatic as a function of location and time. Whether this effect is tectonically significant or not depends on the magnitude of non-lithostatic pressure, and as a result a number of researchers have recently performed numerical simulations to address this. Somewhat disturbingly, they obtained widely differing results with some claiming that overpressures as large as a GPa can occur (Schmalholz et al. 2014), whereas others show that overpressures of exhumed rocks are generally less than 20% and thus insignificant (Li et al. 2010; Burov et al. 2014). In order to understand where these discrepancies come from, we reproduce the simulations of Li et al (2010) of a typical subduction and collision scenario, using an independently developed numerical code (MVEP2). For the same model setup and parameters, we confirm the earlier results of Li et al. (2010) and obtain no more than ~20% overpressure in exhumed rocks of the subduction channel. Yet, a critical assumption in their models is that the subducted crust is laterally homogeneous and that it has a low effective friction angle that is less than 7o. The friction angle of (dry) rocks is experimentally well-constrained to be around 30o, and low effective friction angles require, for example, high-fluid pressures. Whereas high fluid pressures might exist in the sediment-rich upper crust, they are likely to be much lower or absent in the lower crust from which melt has been extracted or in rocks that underwent a previous orogenic cycle. In a next step, we performed several hundred numerical simulations to understand the effects of km-scale heterogeneities and material parameters on pressure magnitudes, using a model setup that is otherwise very similar to the one of Li et al. (2010). Results show that significant non-lithostatic pressures occur if (lower) crustal rocks are dry or if km-scale (nappe-sized) heterogeneities with dryer rocks are present within the crust. Overpressure magnitudes can be up to 1 GPa or 100% and in some cases rock assemblages are temporarily in the coesite stability field at a depth of only 40 km, followed by rapid exhumation to the surface. Tectonic overpressures can vary strongly in magnitude versus time, but peak pressures are present sufficiently long for metamorphic reactions to occur. The presence of heterogeneities can affect the crustal-scaled deformation pattern, and the effective friction angle of crustal-scale rocks (or the dryness of these rocks) is a key parameter that determines the magnitude of non-lithostatic pressures. Our results thus reconcile previous findings and highlight the importance of having an accurate knowledge of the fluid-pressure, initial crustal structure and rock composition during continental collision. If rocks are dry by the time they enter a subduction zone, or are stronger/dryer than surrounding rocks, they are likely to develop significantly higher pressures than nearby rocks. This might explain the puzzling observation that some nappes have very high peak pressures, while juxtaposed nappes have much lower values, without clear structural evidence for deep burial and exhumation along a subduction channel of the high-pressure nappe. Our models might also give a partial explanation of why the reported timescales for high and ultra-high pressure stages of peak metamorphism are often very short. References: Burov, E., Francois, T., Agard, P., Le Pourhiet, L., Meyer, B., Tirel, C., Lebedev, S., Yamato, P., Brun, J.-P., 2014. Tectonophysics. Tectonophysics 631, 212-250. doi:10.1016/j.tecto.2014.04.033 Li, Z.H., Gerya, T.V., Burg, J.-P., 20
NSDL National Science Digital Library
Steven Dutch
This site contains geologic maps of Wisconsin including relief and topography maps; maps of the bedrock geology and elevation, Pleistocene geology, thickness of unconsolidated deposits, and soils; and atlases of geologic history. There is information on: rock types, Paleozoic formations, and the Pleistocene and Precambrian history of Wisconsin; how to obtain a geologic map of personal property; the Niagara Escarpment; castellated mounds; geologic field localities; and unusual weather events in Wisconsin. There is also a data table on earthquakes in Wisconsin.
Heterogeneous porous media in hydrology
NASA Astrophysics Data System (ADS)
Ababou, Rachid
In natural geologic formations, flow and transport-related processes are perturbed by multidimensional and anisotropic material heterogeneities of diverse sizes, shapes, and origins (bedding, layering, inclusions, fractures, grains, for example). Heterogeneity tends to disperse and mix transported quantities and may initiate new transfer mechanisms not seen in ideally homogeneous porous media. Effective properties such as conductivity and dispersivity may not be simple averages of locally measured quantities.The special session, ōEffective Constitutive Laws for Heterogeneous Porous Media,ö convened at AGU's 1992 Fall Meeting in San Francisco, addressed these issue. Over forty-five contributions, both oral and poster, covering a broad range of physical phenomena were presented. The common theme was the macroscale characterization and modeling of flow and flow-related processes in geologic media that are heterogeneous at various scales (from grain size or fracture aperture, up to regional scales). The processes analyzed in the session included coupled hydro-mechanical processes; Darcy-type flow in the saturated, unsaturated, or two-phase regimes; tracer transport, dilution, and dispersion. These processes were studied for either continuous (porous) or discontinuous (fractured) media.
Impact of heterogeneous sulfate formation at mineral dust surfaces on aerosol loads and radiative forcing in
. Sulfate coating on mineral dust particles increases wet deposition of dust, causing a positive anthropogenic forcing due to less sulfate coating at preindustrial times. However, heterogeneous reaction pathways are highly uncertain, which is reflected in the wide spread of reaction pathways and uptake
Formation of indoor nitrous acid (HONO) by light-induced NO2 heterogeneous reactions with white wall paint.
Bartolomei, Vincent; S÷rgel, Matthias; Gligorovski, Sasho; Alvarez, Elena G¾mez; Gandolfo, Adrien; Strekowski, Rafal; Quivet, Etienne; Held, Andreas; Zetzsch, Cornelius; Wortham, Henri
Gaseous nitrogen dioxide (NO2) represents an oxidant that is present in relatively high concentrations in various indoor settings. Remarkably increased NO2 levels up to 1.5 ppm are associated with homes using gas stoves. The heterogeneous reactions of NO2 with adsorbed water on surfaces lead to the generation of nitrous acid (HONO). Here, we present a HONO source induced by heterogeneous reactions of NO2 with selected indoor paint surfaces in the presence of light (300 nm<400 nm). We demonstrate that the formation of HONO is much more pronounced at elevated relative humidity. In the presence of light (5.5 W m(-2)), an increase of HONO production rate of up to 8.6Ę10(9) molecules cm(-2) s(-1) was observed at [NO2]=60 ppb and 50% relative humidity (RH). At higher light intensity of 10.6 (W m(-2)), the HONO production rate increased to 2.1Ę10(10) molecules cm(-2) s(-1). A high NO2 to HONO conversion yield of up to 84% was observed. This result strongly suggests that a light-driven process of indoor HONO production is operational. This work highlights the potential of paint surfaces to generate HONO within indoor environments by light-induced NO2 heterogeneous reactions. PMID:24723352
Stratigraphy, structural geology and metamorphism of the Inwood Marble Formation, northern Manhattan, NYC, NY
Merguerian, Charles
Manhattan, NYC, NY Charles Merguerian, J. Mickey Merguerian, and Nehru E. Cherukupalli Geology Department section of Manhattan starting in the mid-1970s, subsurface data collected during a mapping program were studied from Isham Park, Inwood Hill Park and from other natural exposures in northern Manhattan
GEOLOGY, June 2011 563 Early diagenetic dolomite formation in methanogenic marine
Gilli, Adrian
were deposited near the upwelling area offshore Peru and have a total organic carbon content of ~3 in other ocean margin settings, as well as in ancient organic carbonŁrich sedimentary rocks. GEOLOGICAL of Pleistocene organic carbonŁrich diatom ooze with variable amounts of siliciclastic material. These sediments
Walter, M.Todd
PROCESSES IN THE HIGHLANDS OF ETHIOPIA, NORTHERN BLUE NILE REGION A Thesis Presented to the Faculty geological material and land use type. #12;Water head upstream of the dyke is near or above surface water pressure development and landslides. Saturated area soils have little strength and result in soil
Ray Lemoine, Cedar Bluffs Public Schools, Cedar Bluffs, NE 2008 Understanding Geologic Formations
Frank, Tracy D.
guage) Background: Students should know the rock cycle and the three main types of rocks; sedimentary Materials: Bedded rock samples (or pictures) Fossilized rock samples (or pictures) Pictures from Geology Field Course, or equivalent Rock I.D. flow charts Rock test kits (hardness test, acid test, grain size
Saharan dust and heterogeneous ice formation: Eleven years of cloud observations at a central European EARLINET site
NASA Astrophysics Data System (ADS)
Seifert, P.; Ansmann, A.; Mattis, I.; Wandinger, U.; Tesche, M.; Engelmann, R.; M³ller, D.; PķRez, C.; Haustein, K.
More than 2300 observed cloud layers were analyzed to investigate the impact of aged Saharan dust on heterogeneous ice formation. The observations were performed with a polarization/Raman lidar at the European Aerosol Research Lidar Network site of Leipzig, Germany (51.3░N, 12.4░E) from February 1997 to June 2008. The statistical analysis is based on lidar-derived information on cloud phase (liquid water, mixed phase, ice cloud) and cloud top height, cloud top temperature, and vertical profiles of dust mass concentration calculated with the Dust Regional Atmospheric Modeling system. Compared to dust-free air masses, a significantly higher amount of ice-containing clouds (25%-30% more) was observed for cloud top temperatures from -10░C to -20░C in air masses that contained mineral dust. The midlatitude lidar study is compared with our SAMUM lidar study of tropical stratiform clouds at Cape Verde in the winter of 2008. The comparison reveals that heterogeneous ice formation is much stronger over central Europe and starts at higher temperatures than over the tropical station. Possible reasons for the large difference are discussed.
Heterogeneity of the North Atlantic oceanic lithosphere based on integrated analysis of GOCE satellite gravity and geological data
NASA Astrophysics Data System (ADS)
Barantseva, Olga; Artemieva, Irina; Thybo, Hans; Herceg, Matija
We present the results from modelling the gravity and density structure of the upper mantle for the off-shore area of the North Atlantic region. The crust and upper mantle of the region is expected to be anomalous: Part of the region affected by the Icelandic plume has an anomalously shallow bathymetry, whereas the northern part of the region is characterized by ultraslow spreading. In order to understand the links between deep geodynamical processes that control the spreading rate, on one hand, and their manifestations such as oceanic floor bathymetry and heat flow, on the other hand, we model the gravity and density structure of the upper mantle from satellite gravity data. The calculations are based on interpretation of GOCE gravity satellite data for the North Atlantics. To separate the gravity signal responsible for density anomalies within the crust and upper mantle, we subtract the lower harmonics caused by deep density structure of the Earth (the core and the lower mantle). The gravity effect of the upper mantle is calculated by subtracting the gravity effect of the crust for two crustal models. We use a recent regional seismic model for the crustal structure (Artemieva and Thybo, 2013) based om seismic data together with borehole data for sediments. For comparison, similar results are presented for the global CRUST 1.0 model as well (Laske, 2013). The conversion of seismic velocity data for the crustal structure to crustal density structure is crucial for the final results. We use a combination of Vp-to-density conversion based on published laboratory measurements for the crystalline basement (Ludwig, Nafe, Drake, 1970; Christensen and Mooney, 1995) and for oceanic sediments and oceanic crust based on laboratory measurements for serpentinites and gabbros from the Mid-Atlantic Ridge (Kelemen et al., 2004). Also, to overcome the high degree of uncertainty in Vp-to-density conversion, we account for regional tectonic variations in the Northern Atlantics as constrained by numerous published seismic profiles and potential-field models across the Norwegian off-shore crust (e.g. Breivik et al., 2005, 2007). The results demonstrate the presence of strong gravity and density heterogeneity of the upper mantle in the North Atlantic region. In particular, there is a sharp contrast at the continent-ocean transition, which also allows for recognising mantle gravity anomalies associated with continental fragments and with anomalous oceanic lithosphere.
Methodology for assessing the risk from the disposal of high-level radioactive wastes in deep geologic formations
NASA Astrophysics Data System (ADS)
Cranwell, R. M.; Ortiz, N. R.; Runkle, G. E.
A risk assessment methodology for use in assessing the post closure, long term risk from the disposal of high level radioactive wastes in deep geologic formations. This methodology consists of: (1) techniques for selecting and screening scenarios; (2) models for use in simulating the physical processes and estimating the consequences associated with the occurrence of these scenarios; (3) probabilistic and statistical techniques for use in risk estimates and sensitivity and uncertainty analyses; (4) a procedure for utilizing these models and techniques to arrive at estimates of consequences and risk. The methodology was demonstrated by applying it to the analysis of a hypothetical site containing a bedded salt formation as the host medium for the waste repository. In this demonstration analysis, consequences resulting from the occurrence of several hypothetical scenarios were determined. These consequences were expressed in terms of radionuclide discharges to the biosphere and health effects resulting from these discharges.
A Study of the Relationship of Geological Formation to the NORM
Bursh, Talmage P.; Chriss, Derald
Naturally Occurring Radioactive Materials (NORM) is a common and costly contaminant of produced waters associated with natural gas production and exploration. One way of combating this problem is by identifying the problem beforehand. Our approach to this problem involves development of NORM prediction capabilities based on the geological environment. During quarter thirteen of this project, work has continued under the recently approved revisions. We are also in the final stages of sample acquisition from new sampling sites.
Heterogeneity and Reservoir Quality of Yabus and Samaa Formations, Agordeed Field, Melut Rift Basin, Sudan
Amani Badi; Omer Ali; Abdalla Farwa; Osman Abdullatif
The Tertiary Yabus and Samaa Formations occur within the Melut Rift basin of interior Sudan which is regionally linked to the central and west African rift system. Yabus and Samaa Formations in Agordeed oil field are ones of the most productive oil reservoirs in Melut basin and are composed of sandstones and mudstones lithofacies that differ in size and length
3-D heterogeneous field data versus 2-D simulations. How can it be accomplished in a sedimentary porous formation?
NASA Astrophysics Data System (ADS)
Darvini, G.; Salandin, P.
To analyze the impact of the hydraulic conductivity K spatial variability in a real field case (as an example to delimitate a well catchment), numerical simulations can be reasonably developed in a two-dimensional vertical average context. Nevertheless the plume evolution is a consequence of a more complex three-dimensional heterogeneous structure whose vertical variability dominates the dispersion phenomena at local scale. In larger domains, the effect of the vertical heterogeneity combines itself with that one due to the horizontal variability of K, and only when the plume has travelled a large number of (horizontal) integral scales, its evolution can be analyzed in a regional context, under the hypothesis that the transmissivity spatial distribution prevails. Until this limit is reached, the vertical and horizontal variability of K are combined to give a fully 3-D dispersion process. In all these situations, to successfully accomplish the 3-D heterogeneous structure of the aquifer in 2-D simulations, more than the planimetric depth-averaged variability of K must be accounted for. To define the uncertainty related to the use of different planimetric schematizations of the real hydraulic conductivity spatial distribution, we present here the results of some numerical experiments that compare the 3-D plume evolution with 2-D simulations developed by tacking into account different hydraulic conductivity distribution schematization, by considering a hierarchical architecture of media also. This description of a sedimentary formation combined with the finite size of the plume requires theoretical and numerical tools able to take into account the flow field inhomogeneity and the ergodicity lack that characterize the transport phenomena. Following this way it will be possible to quantify / reduce the uncertainty related to a 2-D schematization in a large number of real cases where the domain spans between the local and the regional scale and whose dimension may lead to a numerical nightmare in terms of fully 3-D discretization.
Geologic map of the Peach Orchard Flat quadrangle, Carbon County, Wyoming, and descriptions of new stratigraphic units in the Upper Cretaceous Lance Formation and Paleocene Fort Union Formation, eastern Greater Green River Basin, Wyoming-Colorado
Honey, J.D.; Hettinger, R.D.
This report provides a geologic map of the Peach Orchard Flat 7.5-minute quadrangle, located along the eastern flank of the Washakie Basin, Wyo. Geologic formations and individual coal beds were mapped at a scale of 1:24,000; surface stratigraphic sections were measured and described; and well logs were examined to determine coal correlations and thicknesses in the subsurface. In addition, four lithostratigraphic units were named: the Red Rim Member of the Upper Cretaceous Lance Formation, and the China Butte, Blue Gap, and Overland Members of the Paleocene Fort Union Formation.
Making a Geologic Cross Section Name _____________________________ Geology 100 Harbor Section
Harbor, David
of cross section A for help) 2. What symbols represent these formations and in what geologic time periodsp. 1 Making a Geologic Cross Section Name _____________________________ Geology 100 ┬Ł Harbor Section Your task is to complete a cross section of geologic structures from a geologic map. Please do
Geological and geochemical model of formation of oil and gas accumulations in the South Caspian basin
Narimanov, A.A.
The South Caspian Sea, Azerbaijan, has been a major petroleum producer since 1848 and is still one of the premier prospective areas for oil and gas in the Soviet Union. Many years of research studies suggest oil and gas in the Soviet Union. Many years of research studies suggest an area of increased prospectivity in the deeper part of the Caspian Sea. Geologic history recorded that a trough developed during the Mesozoic through the Tertiary. The sedimentary sequence is up to 23 km thick. The Pliocene sequence is the major proven productive and prospective interval. Multiple stages of active sedimentation and tectonism took place starting in the early Pliocene and ending in the late Pliocene. Traps were formed and destroyed during the early to late Pliocene. The final tectonic events during the late Pliocene trapped the remigrated oil. Gas and gas condensate probably are within the lower reaches of the basin. Because of the rapid deposition, mud volcanoes were also active. Many are still active today and can be noted in proximity to hydrocarbon deposits. Rapid subsidence and deposition, and anomalously low geothermal regime, and a low maturity of sampled organic matter from the Pliocene section leads to the hypothesis of hydrocarbon generation at depth from older sedimentary rocks. With this proposed geological and geochemical model, the prospectivity for oil and gas deposits is greatly enhanced in aerial extent and possibly to a depth of 9 km.
Spontaneous Formation of Tumorigenic Hybrids between Breast Cancer and Multipotent Stromal Cells Is a Source of Tumor Heterogeneity
Rappa, Germana; Mercapide, Javier; Lorico, Aurelio
Breast cancer progression involves cancer cell heterogeneity, with generation of invasive/metastatic breast cancer cells within populations of nonmetastatic cells of the primary tumor. Sequential genetic mutations, epithelial-to-mesenchymal transition, interaction with local stroma, and formation of hybrids between cancer cells and normal bone marrow¢derived cells have been advocated as tumor progression mechanisms. We report herein the spontaneous in vitro formation of heterotypic hybrids between human bone marrow¢derived multipotent stromal cells (MSCs) and two different breast carcinoma cell lines, MDA-MB-231 (MDA) and MA11. Hybrids showed predominantly mesenchymal morphological characteristics, mixed gene expression profiles, and increased DNA ploidy. Both MA11 and MDA hybrids were tumorigenic in immunodeficient mice, and some MDA hybrids had an increased metastatic capacity. Both in culture and as xenografts, hybrids underwent DNA ploidy reduction and morphological reversal to breast carcinoma¢like morphological characteristics, while maintaining a mixed breast cancer¢mesenchymal expression profile. Analysis of coding single-nucleotide polymorphisms by RNA sequencing revealed genetic contributions from both parental partners to hybrid tumors and metastasis. Because MSCs migrate and localize to breast carcinoma, our findings indicate that formation of MSC¢breast cancer cell hybrids is a potential mechanism of the generation of invasive/metastatic breast cancer cells. Our findings reconcile the fusion theory of cancer progression with the common observation that breast cancer metastases are generally aneuploid, but not tetraploid, and are histopathologically similar to the primary neoplasm. PMID:22542847
Ernest A. Mancini
The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 2 of the project has been reservoir characterization, 3-D modeling and technology transfer. This effort has included six tasks: (1) the study of rockfluid interactions, (2) petrophysical and engineering characterization, (3) data integration, (4) 3-D geologic modeling, (5) 3-D reservoir simulation and (6) technology transfer. This work was scheduled for completion in Year 2. Overall, the project work is on schedule. Geoscientific reservoir characterization is essentially completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions is near completion. Observations regarding the diagenetic processes influencing pore system development and heterogeneity in these reef and shoal reservoirs have been made. Petrophysical and engineering property characterization has been essentially completed. Porosity and permeability data at Appleton and Vocation Fields have been analyzed, and well performance analysis has been conducted. Data integration is up to date, in that, the geological, geophysical, petrophysical and engineering data collected to date for Appleton and Vocation Fields have been compiled into a fieldwide digital database. 3-D geologic modeling of the structures and reservoirs at Appleton and Vocation Fields has been completed. The model represents an integration of geological, petrophysical and seismic data. 3-D reservoir simulation of the reservoirs at Appleton and Vocation Fields has been completed. The 3-D geologic model served as the framework for the simulations. A technology workshop on reservoir characterization and modeling at Appleton and Vocation Fields was conducted to transfer the results of the project to the petroleum industry.
Studies of the formation, chemical reactivity, and properties of small clusters: Application to an understanding of aerosol formation and heterogeneous chemistry
Castleman, A.W. Jr.
The small cluster program involves (1) studies of reactions related to formation and growth of heteromolecular clusters and their thermochemical properties, (2) studies of photoinitiated processes in clusters, (3) investigations related to heterogeneous reactions including the influence of reaction centers on the interconversion, and (4) theoretical calculations of properties, dynamics, and structure. A major thrust of the work during the past year has been devoted to a study of the role of ionization and the presence of ions on reactions and energetics. During the past few months, particular attention has been paid to systems having varying proton affinities. From the data, we can determine the influence of these values on the nature of the reactions and ascertain the ultimate chemical nature of the ionization center formed as a result of the reactions. 83 refs., 12 figs., 2 tabs.
Modeling the composition of the pore water in a clay-rock geological formation (Callovo-Oxfordian, France)
NASA Astrophysics Data System (ADS)
Leroy, P.; Revil, A.; Altmann, S.; Tournassat, C.
The interstitial water contained in the microporosity of highly compact clay-rich media does not obey the classical condition usually used to derive the ionic composition of a solution. This is because the requirement for global electroneutrality of a charged microporous body (one having a significant fraction of pores with dimensions of the same order of size as the diffuse double layer) implies that the net charge density of the pore water must balance the deficiency (or the excess) of electrical charge carried by the solid matrix. In order to determine the solution composition in the micropores of a clay-rock, we first generalize the Donnan equilibrium conditions for the case of a multi-ionic electrolyte, with partitioning of the charge compensating counterions between the Stern and the diffuse layers A material-specific geochemical equilibrium model, incorporating an electrical triple layer model for adsorption reactions, is used to calculate the partition coefficient for the compensating ion charge (i.e., the fraction of charge in the Stern layer). This is then used to calculate the osmotic pressure and ionic composition of the pore water in the micropores. The material considered in this study is the argillite clay-rock sampled from the Callovo-Oxfordian geological formation under consideration in France for a deep geological disposal facility for radioactive waste.
Effects on the mobility of metals from acidification caused by possible CO? leakage from sub-seabed geological formations.
de Orte, Manoela Roman¾; Sarmiento, Aguasanta M; Basallote, Maria Dolores; RodrĒguez-Romero, Araceli; Riba, Inmaculada; Delvalls, Angel
Carbon dioxide capture and storage (CCS) in submarine geological formations has been proposed as a mitigation measure for the prevention of global warming. However, leakage of CO2 to overlying sediments may occur over time, leading to various effects on ecosystems. Laboratory-scale experiments were performed, involving direct release of carbon dioxide into sediment, inside non-pressurized chambers, in order to provide data on the possible effects of CO2 leakage from geological storage sites on the fate of several metals. Marine sediments from three sites with different levels of contamination were sampled and submitted to acidification by means of CO2 injection. The experiment lasted 10 days and sediment samples were collected at the beginning and end of the experiment and pore water was extracted for metal analysis. The results revealed that mobility of metals from sediment to pore water depends on the site, metal and length of time exposed. Mobilization of the metals Al, Fe, Zn, Co, Pb and Cu increases with acidification, and this response generally increases with time of exposure to CO2 injection. The geochemical model applied suggests that acidification also influences the speciation of metals, transforming metals and metalloids, like As, into species much more toxic to biota. The data obtained from this study will be useful for calculating the potential risk of CCS activities to the marine environment. PMID:24144940
Simulating Geologic Co-sequestration of Carbon Dioxide and Hydrogen Sulfide in a Basalt Formation
Bacon, Diana H.; Ramanathan, Ramya; Schaef, Herbert T.; McGrail, B. Peter
Co-sequestered CO2 with H2S impurities could affect geologic storage, causing changes in pH and oxidation state that affect mineral dissolution and precipitation reactions and the mobility of metals present in the reservoir rocks. We have developed a variable component, non-isothermal simulator, STOMP-COMP (Water, Multiple Components, Salt and Energy), which simulates multiphase flow gas mixtures in deep saline reservoirs, and the resulting reactions with reservoir minerals. We use this simulator to model the co-injection of CO2 and H2S into brecciated basalt flow top. A 1000 metric ton injection of these supercritical fluids, with 99% CO2 and 1% H2S, is sequestered rapidly by solubility and mineral trapping. CO2 is trapped mainly as calcite within a few decades and H2S is trapped as pyrite within several years.
The Use of Photo-projects and Term Projects in Large-Format (200+ Students) Introductory Geology Courses.
NASA Astrophysics Data System (ADS)
Giles, A. N.; Wilkie, K. M.
Photo-projects have long been utilized as a way of getting students in introductory geology courses to apply what they have learned in lecture to the outcrop and landscape. While the projects have many benefits, we have found that with large-format classes of 200+ students, where a mandatory field trip is logistically impossible, many problems can arise. One problem has been that of consistent and timely grading, which can be addressed by a project that can be turned in throughout the course of the semester and by utilizing a grading rubric. Also, in many cases, students simply take photographs of "scenery" and then try to identify features/processes with little thought as to whether that particular feature/process can occur in that geologic setting (such as identifying features as having a glacial origin in a non-glaciated terrain.) These types of problem can be attributed to the student's lack of knowledge of the geology of the area within which the photographs were taken and having little to no field instruction. Many of these problems can be addressed by utilizing a term project that combines elements of both research and the traditional photo project. The student chooses a specific area/region (i.e. a national park) that the student will/has actually visit(ed) and is then required to do background research before attempting to identify features and processes in photographs they have taken from the area. Here we present details of such a project that involves students performing research activities in three stages: The history/geologic setting of the area, the specific lithology of the area, and then the hydrology of the area, with each being completed at specified times throughout the semester. The final stage is the photo project component where the student identifies and interprets the features/processes in photographs from the area. The research provides the student with a framework within which they can identify and interpret the features/processes that are likely to be seen in their area.
Leveraging Regional Exploration to Develop Geologic Framework for CO2 Storage in Deep Formations in Midwestern United States
Neeraj Gupta
Obtaining subsurface data for developing a regional framework for geologic storage of CO{sub 2} can require drilling and characterization in a large number of deep wells, especially in areas with limited pre-existing data. One approach for achieving this objective, without the prohibitive costs of drilling costly standalone test wells, is to collaborate with the oil and gas drilling efforts in a piggyback approach that can provide substantial cost savings and help fill data gaps in areas that may not otherwise get characterized. This leveraging with oil/gas drilling also mitigates some of the risk involved in standalone wells. This collaborative approach has been used for characterizing in a number of locations in the midwestern USA between 2005 and 2009 with funding from U.S. Department of Energy's National Energy Technology Laboratory (DOE award: DE-FC26-05NT42434) and in-kind contributions from a number of oil and gas operators. The results are presented in this final technical report. In addition to data collected under current award, selected data from related projects such as the Midwestern Regional Carbon Sequestration Partnership (MRCSP), the Ohio River Valley CO{sub 2} storage project at and near the Mountaineer Plant, and the drilling of the Ohio Stratigraphic well in Eastern Ohio are discussed and used in the report. Data from this effort are also being incorporated into the MRCSP geologic mapping. The project activities were organized into tracking and evaluation of characterization opportunities; participation in the incremental drilling, basic and advanced logging in selected wells; and data analysis and reporting. Although a large number of opportunities were identified and evaluated, only a small subset was carried into the field stage. Typical selection factors included reaching an acceptable agreement with the operator, drilling and logging risks, and extent of pre-existing data near the candidate wells. The region of study is primarily along the Ohio River Valley corridor in the Appalachian Basin, which underlies large concentrations of CO{sub 2} emission sources. In addition, some wells in the Michigan basin are included. Assessment of the geologic and petrophysical properties of zones of interest has been conducted. Although a large number of formations have been evaluated across the geologic column, the primary focus has been on evaluating the Cambrian sandstones (Mt. Simon, Rose Run, Kerbel) and carbonates layers (Knox Dolomite) as well as on the Silurian-Devonian carbonates (Bass Island, Salina) and sandstones (Clinton, Oriskany, Berea). Factors controlling the development of porosity and permeability, such as the depositional setting have been explored. In northern Michigan the Bass Islands Dolomite appears to have favorable reservoir development. In west central Michigan the St. Peter sandstone exhibits excellent porosity in the Hart and Feuring well and looks promising. In Southeastern Kentucky in the Appalachian Basin, the Batten and Baird well provided valuable data on sequestration potential in organic shales through adsorption. In central and eastern Ohio and western West Virginia, the majority of the wells provided an insight to the complex geologic framework of the relatively little known Precambrian through Silurian potential injection targets. Although valuable data was acquired and a number of critical data gaps were filled through this effort, there are still many challenges ahead and questions that need answered. The lateral extent to which favorable potential injection conditions exist in most reservoirs is still generally uncertain. The prolongation of the characterization of regional geologic framework through partnership would continue to build confidence and greatly benefit the overall CO{sub 2} sequestration effort.
Geological Sequestration of CO2 by Hydrous Carbonate Formation with Reclaimed Slag
Von L. Richards; Kent Peaslee; Jeffrey Smith
The concept of this project is to develop a process that improves the kinetics of the hydrous carbonate formation reaction enabling steelmakers to directly remove CO2 from their furnace exhaust gas. It is proposed to bring the furnace exhaust stream containing CO2 in contact with reclaimed steelmaking slag in a reactor that has an environment near the unit activity of water resulting in the production of carbonates. The CO2 emissions from the plant would be reduced by the amount sequestered in the formation of carbonates. The main raw materials for the process are furnace exhaust gases and specially prepared slag.
Inventory of Shale Formations in the US, Including Geologic, Hydrological, and Mechanical Characteristics
Dobson, Patrick; Houseworth, James
The objective of this report is to build upon previous compilations of shale formations within many of the major sedimentary basins in the US by developing GIS data delineating isopach and structural depth maps for many of these units. These data are being incorporated into the LANL digital GIS database being developed for determining host rock distribution and depth/thickness parameters consistent with repository design. Methods were developed to assess hydrological and geomechanical properties and conditions for shale formations based on sonic velocity measurements.
Local-heterogeneous responses and transient dynamics of cage breaking and formation in colloidal fluids.
Nag, Preetom; Teramoto, Hiroshi; Li, Chun-Biu; Terdik, Joseph Z; Scherer, Norbert F; Komatsuzaki, Tamiki
Quantifying the interactions in dense colloidal fluids requires a properly designed order parameter. We present a modified bond-orientational order parameter, ??6, to avoid problems of the original definition of bond-orientational order parameter. The original bond-orientational order parameter can change discontinuously in time but our modified order parameter is free from the discontinuity and, thus, it is a suitable measure to quantify the dynamics of the bond-orientational ordering of the local surroundings. Here we analyze ??6 in a dense driven monodisperse quasi-two-dimensional colloidal fluids where a single particle is optically trapped at the center. The perturbation by the trapped and driven particle alters the structure and dynamics of the neighboring particles. This perturbation disturbs the flow and causes spatial and temporal distortion of the bond-orientational configuration surrounding each particle. We investigate spatio-temporal behavior of ??6 by a Wavelet transform that provides a time-frequency representation of the time series of ??6. It is found that particles that have high power in frequencies corresponding to the inverse of the timescale of perturbation undergo distortions of their packing configurations that result in cage breaking and formation dynamics. To gain insight into the dynamic structure of cage breaking and formation of bond-orientational ordering, we compare the cage breaking and formation dynamics with the underlying dynamical structure identified by Lagrangian Coherent Structures (LCSs) estimated from the finite-time Lyapunov exponent (FTLE) field. The LCSs are moving separatrices that effectively divide the flow into distinct regions with different dynamical behavior. It is shown that the spatial distribution of the FTLE field and the power of particles in the wavelet transform have positive correlation, implying that LCSs provide a dynamic structure that dominates the dynamics of cage breaking and formation of the colloidal fluids. PMID:25217951
Phase 1 user instruction manual. A geological formation - drill string dynamic interaction finite element program (GEODYN)
Tinianow, M.A.; Rotelli, R.L. Jr.; Baird, J.A.
User instructions for the GEODYN Interactive Finite Element Computer Program are presented. The program is capable of performing the analysis of the three-dimensional transient dynamic response of a Polycrystalline Diamond Compact Bit - Bit Sub arising from the intermittent contact of the bit with the downhole rock formations. The program accommodates non-linear, time dependent, loading and boundary conditions.
Secondary particle formation and evidence of heterogeneous chemistry during a wood smoke episode in Texas
NASA Astrophysics Data System (ADS)
Buzcu, B.; Yue, Z. W.; Fraser, M. P.; Nopmongcol, U.; Allen, D. T.
To evaluate the impact of regional wildfires in east Texas on fine particulate matter concentration and composition, source apportionment calculations were performed on a set of samples collected at three sites in Houston during a wood smoke episode. Separately, samples collected at the same sites on days not influenced by wood smoke, were analyzed for comparison. The analysis of the data collected on non-wood smoke episode days indicated that the major contributors to PM2.5 mass were secondary sulfate, diesel and gasoline powered vehicles, other organics (difference between the measured organic mass by carbon (OMC) and the sum of the primary OC source contributions), wood combustion and meat cooking. Secondary sulfate (not apportioned to a primary source) represented almost 100% of the sulfate measured whereas primary sources were found to account for the majority of the measured organic carbon at three sites (64-69%). On the wood smoke episode days, major sources of PM2.5 were found to be the same as on the days without wood smoke, except for the contribution of the meat cooking source, which became insignificant on the wood smoke episode days. The contribution of the wood combustion source increased by an average of 200% at all sites on wood smoke episode days, whereas the contributions of other primary sources did not increase significantly during the wood smoke episode. PM2.5 mass almost doubled during the wood smoke episode, largely because of the contributions of the secondary sources. The mass concentrations of secondary sulfate and organics not attributed to primary sources increased 68% and 228% at each site, respectively, during the wood smoke episode. The increase in the contributions of secondary sulfate aerosols during the wood smoke episode was examined using a 3-D photochemical grid model. The simulations, together with ambient data, indicated that the increases in sulfate concentrations observed during this wood smoke episode were consistent with heterogeneous/surface reactions on wood smoke particles.
Petroleum geology of the Norphlet formation (Upper Jurassic), S. W. and offshore Alabama
Mancini, E.A.; Mink, R.M.; Bearden, B.L.
Recent successful gas test in the Norphlet formation (up to 26 million CF/day) at depths exceeding 20,500 ft in the Mobile Bay area demonstrate a high potential for hydrocarbon production in the Alabama offshore area. In addition, wells drilled in the upper Mobile Bay area could encounter gas condensate in the Norphlet formation; gas condensate is being produced from wells in Hatter's Pond field about 14 miles north of Mobile Bay and 45 miles north of the Lower Mobile Bay-Mary Ann field. With continued petroleum exploration, additional Norphlet petroleum fields should be discovered in southwestern and offshore Alabama in the years ahead. In light of the recent discoveries in Escambia County and in the lower Mobile Bay area, Mobile, Baldwin, and Escambia counties and Mobile Bay appear to be the most prospective hydrocarbon areas.
Petroleum geology of MC3 member, Mississippian Mission Canyon Formation, Pierson area, southwestern Manitoba
M. Husain; S. P. Halabura
Mississippian beds in the Manitoba portion of the Williston basin produce oil from a series of stratigraphic units where porous cyclic carbonates are truncated by pre-Mesozoic erosion and sealed by Amaranth (Watrous\\/Spearfish) strata. In the Pierson area of southwest Manitoba, oil is trapped within the MC-3 member of the Mission Canyon Formation, correlative with the Alida beds of Saskatchewan. Production
The geology and mechanics of formation of the Fort Rock Dome, Yavapai County, Arizona
Fuis, Gary S.
The Fort Rock Dome, a craterlike structure in northern Arizona, is the erosional product of a circular domal uplift associated with a Precambrian shear zone exposed within the crater and with Tertiary volcanism. A section of Precambrian to Quaternary rocks is described, and two Tertiary units, the Crater Pasture Formation and the Fort Rock Creek Rhyodacite, are named. A mathematical model of the doming process is developed that is consistent with the history of the Fort Rock Dome.
Zhang, Dongxiao
was performed by an employee of the U.S. Government or under U.S. Government contract. The U.S. GovernmentŁ577 Abstract. Geological formations are ubiquitously heterogeneous, and the equations that govern flow the KLME method to solve more realistic large-scale flow problems. Key words. Monte Carlo simulations
Geology of the Hanna Formation, Hanna Underground Coal Gasification Site, Hanna, Wyoming
Oliver, R.L.; Youngberg, A.D.
The Hanna Underground Coal Gasification (UCG) study area consists of the SW1/4 of Section 29 and the E1/2SE1/4 of Section 30 in Township 22 North, Range 81 West, Wyoming. Regionally, this is located in the coal-bearing Hanna Syncline of the Hanna Basin in southeast Wyoming. The structure of the site is characterized by beds dipping gently to the northeast. An east-west fault graben complex interrupts this basic trend in the center of the area. The target coal bed of the UCG experiments was the Hanna No. 1 coal in the Hanna Formation. Sedimentary rocks comprising the Hanna Formation consist of a sequence of nonmarine shales, sandstones, coals and conglomerates. The overburden of the Hanna No. 1 coal bed at the Hanna UCG site was divided into four broad local stratigraphic units. Analytical studies were made on overburden and coal samples taken from cores to determine their mineralogical composition. Textural and mineralogical characteristics of sandstones from local stratigraphic units A, B, and C were analyzed and compared. Petrographic analyses were done on the coal including oxides, forms of sulfur, pyrite types, maceral composition, and coal rank. Semi-quantitative spectrographic and analytic geochemical analyses were done on the overburden and coal and relative element concentrations were compared. Trends within each stratigraphic unit were also presented and related to depositional environments. The spectrographic analysis was also done by lithotype. 34 references, 60 figures, 18 tables.
Geologic Map of Upper Cretaceous and Tertiary Strata and Coal Stratigraphy of the Paleocene Fort Union Formation, Rawlins-Little Snake River Area, South-Central Wyoming
Hettinger, R.D.; Honey, J.G.; Ellis, M.S.; Barclay, C.S.V.; East, J.A.
This report provides a map and detailed descriptions of geologic formations for a 1,250 square mile region in the Rawlins-Little Snake River coal field in the eastern part of the Washakie and Great Divide Basins of south-central Wyoming. Mapping of geologic formations and coal beds was conducted at a scale of 1:24,000 and compiled at a scale of 1:100,000. Emphasis was placed on coal-bearing strata of the China Butte and Overland Members of the Paleocene Fort Union Formation. Surface stratigraphic sections were measured and described and well logs were examined to determine the lateral continuity of individual coal beds; the coal-bed stratigraphy is shown on correlation diagrams. A structure contour and overburden map constructed on the uppermost coal bed in the China Butte Member is also provided.
Geologic and metallogenic aspects concerning the Nahuelbuta mountains banded iron formation, Chile
NASA Astrophysics Data System (ADS)
Oyarz·n, R.; Clemmey, H.; Collao, S.
Paleozoic banded-iron-formation (BIF) deposits occur within the Nahuelbuta-Queule Complex (south central Chile) which hosts the following stratigraphic units: Cabo Tir·a (green schists, mica schists, and metacherts), Lleu-Lleu (iron-bearing metacherts, mica schists, and serpentinites), and Colcura (metagraywackes and metapelites). The lithological, structural, and geochemical characteristics of the Lleu-Lleu and Cabo Tir·a units indicate that they were part of a tectonic mķlange accreted to the South American paleocontinent during the Paleozoic. BIF ores are restricted to the Lleu-Lleu metacherts and are characterized by oxide-silicate-sulfide BIF facies. The iron-bearing metacherts present mineralogical and geochemical characteristics close to the volcanogenic BIF types and are thought to have been formed by submarine volcanic exhalative activity.
Geological evolution and analysis of confirmed or suspected gas hydrate localities: Volume 6, Basin analysis, formation and stability of gas hydrates in the Panama Basin
Krason, J.; Ciesnik, M.
This report presents a geological description of the Panama Basin, including regional and local structural settings, geomorphology, geological history, stratigraphy, and physical properties. It provides the necessary regional and geological background for more in-depth research of the area. Detailed discussion of bottom simulating acoustic reflectors, sediment acoustic properties, distribution of hydrates within the sediments, and the relation of hydrate distribution to other features such as salt diapirism are also included. The formation and stabilization of gas hydrates in sediments are considered in terms of phase relations, nucleation, and crystallization constraints, gas solubility, pore fluid chemistry, inorganic diagenesis, and sediment organic content. Together with a depositional analysis of the area, this report is a better understanding of the thermal evolution of the locality. It should lead to an assessment of the potential for both biogenic and thermogenic hydrocarbon generation. 63 refs., 38 figs., 7 tabs.
Geological evolution and analysis of confirmed or suspected gas hydrate localities: Volume 9, Formation and stability of gas hydrates of the Middle America Trench
Finley, P.; Krason, J.
This report presents a geological description of the Pacific margin of Mexico and Central America, including regional and local structural settings, geomorphology, geological history, stratigraphy, and physical properties. It provides the necessary regional and geological background for more in-depth research of the area. Detailed discussion of bottom simulating acoustic reflectors, sediment acoustic properties, and distribution of hydrates within the sediments are also included in this report. The formation and stabilization of gas hydrates in sediments are considered in terms of phase relations, nucleation, and crystallization constraints, gas solubility, pore fluid chemistry, inorganic diagenesis, and sediment organic content. Together with a depositional analysis of the area, this report is a better understanding of the thermal evolution of the locality. It should lead to an assessment of the potential for both biogenic and thermogenic hydrocarbon generation. 150 refs., 84 figs., 17 tabs.
Preliminary modeling of the long-term fate of CO2 following injection into deep geological formations
Strazisar, B.R.; Shu, C.; Hedges, S.W.
The injection of CO2 into deep saline aquifers is a potential option for greenhouse gas mitigation. However, several key issues, such as underground storage time and the fate of the injected CO2, must be studied before this option becomes economically and socially acceptable. In the current study, a one-dimensional reactive mass-transport model was used to predict the long-term chemical behavior of a deep saline aquifer following CO2 injection, far away from the injection site and representative of basin-scale migration and long-term fate. The dissolution of the injected CO2 into brine causes a sharp drop in pH, and consequently, the acidic brine aggressively reacts with aquifer minerals. Our model also predicts the dissolution of aluminosilicate minerals with the formation of secondary minerals and the precipitation and dissolution of carbonate minerals and is consistent with laboratory-scale CO2 core-flooding experiments. However, the extent and development of reaction fronts depend on the reaction rates used. For example, our modeling results indicate that the transport of carbon can be significantly retarded with respect to the flow of the brine itself, and a significant amount of injected CO2 is immobilized because of mineral trapping. The precise locations and patterns of the carbon reactive transport are sensitive to the reaction rates used, illustrating the need for improved knowledge of reaction kinetics, particularly the in-situ rates of dissolution and precipitation of aluminosilicate minerals, in evaluating mineral trapping of CO2 in deep geological formations.
High-resolution photo geologic mapping of the Tuscan Formation cliffs in the BCCER and Upper Bidwell Park, Chico CA
NASA Astrophysics Data System (ADS)
gonzalez, M.; Greene, T.
The Tuscan Formation rocks make up the uppermost cliffs of the Big Chico Creek Ecological Reserve (BCCER) and Upper Bidwell Park. These rocks are composed of 3.2 to 1.8 million year old tuffs, conglomerate and sandstone dominated by volcanic clasts, as well as siltstone and mudstone mostly derived from the ancient Mt. Yana volcanic complex near Lake Almanor. This study attempts to investigate stratal geometries of Tuscan deposits in the BCCER and Upper Bidwell Park by mapping stratigraphic sections and using high resolution aerial geologic photomosaics of the Tuscan rocks. In order to obtain the best perspective of the rocks, the photos have been taken directly perpendicular to the cliff face using a helicopter and high resolution photography. With these photos, detailed layering and features of the Tuscan, both in the breccia units and the interbedded fluvial units, can be detected. These 'head on' photos are the best way to see erosional surfaces, pinch-outs, and individual flow units. They can also be used to document how well these features correlate down-canyon. Additionally, aerial photos provide a foundation for recognizing larger scale features and trends which would otherwise go unnoticed (channel flow direction, cross-cutting flows). One example of these larger scale features are two larger debris flows at the top of the unit that are best seen by the aerial photos. By foot, these debris flows can be difficult to access because of steep terrain and vegetation cover. These photos will not only aid in the study of the Tuscan deposits, but will potentially benefit other research focused on the hydrology, ecology, or archeology of Upper Bidwell Park and the BCCER. The Tuscan Formation. Debris Flow layers can easily be mapped from high-resolution photos
Phased Array Approach To Retrieve Gases, Liquids, Or Solids From Subsurface And Subaqueous Geologic Or Man-Made Formations
Rynne, Timothy M. (Long Beach, CA); Spadaro, John F. (Huntington Beach, CA); Iovenitti, Joe L. (Pleasant Hill, CA); Dering, John P. (Lakewood, CA); Hill, Donald G. (Walnut Creek, CA)
A method of enhancing the remediation of contaminated soils and ground water, production of oil and gas, and production of any solid, gas, and/or liquid from subsurface geologic and man-made formations including the steps of estimating the geometric boundaries of the region containing the material to be recovered, drilling a recovery well(s) into subsurface in a strategic location to recover the material of interest, establishing multiple sources of acoustical power in an array about and spaced-apart from the surface or at various depths below the surface in a borehole(s) and/or well(s), directing a volume of acoustical excitation from the sources into the region containing the material to be recovered, the excitation in the form of either controllable sinusoidal, square, pulsed, or various combinations of these three waveforms, and controlling the phasing, frequency, power, duration, and direction of these waveforms from the sources to increase and control the intensity of acoustical excitation in the region of the material to be recovered to enhance. the recovery of said material from the recovery well(s). The invention will augment any technology affecting the removal of materials from the subsurface.
Integrations of AUTOMESH-2D mesh generator and TOUGH2 model to simulate CO2 migrations in complex geological formations in central Taiwan
NASA Astrophysics Data System (ADS)
Lee, I.; Ni, C.; Lu, C.
The carbon dioxide capture and storage (CCS) are recognized to be feasible techniques for mitigation of carbon dioxide emissions. Due to large capacity and availability of geologic formations for most countries, the geologic storage methods are well developed and many sites are on the stage for possible large-scale operations. Numerical simulation of CO2 migration in geologic formations can provide key information for predicting CO2 plumes before field-scale operations or pilot tests are conducted. In this study we modified the AUTOMESH-2D mesh generator for TOUGH2-ECO2N model to investigate the structural trapping and solubility trapping processes during the sequestration of carbon dioxide in a brine aquifer in central Taiwan. Based on the observations from near shore seismic profiles, the complex, three-dimensional unstructured meshes are generated by using our modified program and are integrated with the well-developed TOUGH2-ECO2N model for simulating CO2 injections. With the specified injection in Kueichulin Formation and injection rate of 100Mt/year in 20 years, the results of 100 years simulation show that the mean CO2 plumes migrate 4km in 100 years from the injection locations. The sensitivity analyses based on different formation permeabilites show that the locations of CO2 plume fronts might vary from hundreds of meters to kilometers.
Geologic uses of formation microscanner (FMS) in Antelope Shale Cymric field, San Joaquin Valley, California
White, R.E.
A comparison between formation microscanner (FMS) log and core from the Cymric field was made to determine the effectiveness of the FMS in characterizing the Antelope Shale. Comparisons of the FMS log and core were based on a detailed core description, petrography, scanning electron microscopy (SEM), and mineralogical analysis. Results indicate that the FMS log in the Antelope Shale is useful for (1) distinguishing between certain rock types, (2) determining bed thickness and bedding-plane orientations, and (3) detecting some fractures and determining some fracture-plane orientations. However, the FMS log shows some ambiguous responses that can be interpreted only by comparison with the core or other wireline logs. Based on resistivity contrasts, three rock-type groups can be distinguished. From least to most resistive, they are (1) mudstone, (2) argillaceous diatomite/Porcelanite, and (3) sandstone, dolostone, clay-poor porcelanite, and chert. A bed thickness of 1 cm or greater can be resolved using the FMS. Bedding-plane orientations can also be determined and provide a means to orient the core. Detection of fractures in the Antelope Shale is generally limited to those fractures within rock type that display intermediate ranges of resistivity and to the large-scale fractures. Fracture-plane orientations of some fractures can be determined; however, because of poor fracture development in the majority of Antelope Shale rock types, fractures are commonly not visible on both FMS-pad images. This makes determination of fracture-plane orientation difficult, if not impossible, for many of these fractures.
Neoproterozoic Cana Brava chrysotile deposit (Goißs, Brazil): Geology and geochemistry of chrysotile vein formation
NASA Astrophysics Data System (ADS)
Biondi, JoŃo Carlos
The Cana Brava chrysotile asbestos deposit of Goißs, Brazil, contains approximately 150 Mt of ore with an average of 3.5 wt.% of cross-fiber chrysotile and lies in the differentiated, mafic-ultramafic Neoproterozoic Cana Brava complex. This complex was formed at approximately 0.79 Ga and metamorphosed at 0.77 to 0.76 and 0.63 Ga. The 0.77 to 0.76 Ga metamorphic event was a high-grade one that transformed the mafic and ultramafic rocks into meta-peridotites and meta-pyroxenites. The low-grade 0.63 Ga metamorphism allowed the formation of black, red and brown serpentinite, graphitic, magnesite-rich talc serpentinite, and rodingite, which became folded and foliated. At the end of the 0.63 Ga metamorphism, black serpentinites were oxidized to form red serpentinites, the main type of serpentinite that outcrops today at the Cana Brava mineralized region. Post-metamorphic fluids reactivated the process of serpentinization, thereby generating massive green serpentinite from the red. Green formed on the most fractured zones, and double red and green reaction rims formed on the sides of the veins located outside the green serpentinite zones. This process did not cause significant variation in the volume of the rocks and resulted in a strongly reducing system thanks to the loss of Fe2O3 and iron and the subsequent crystallization of magnetite within veinlets and altered rocks. Low angle shear, developed under brittle conditions, caused hydraulic fracturing and the generation of oversaturated, oxidizing fluids that crystallized the cross-fiber chrysotile inside open fractures. Very densely fractured zones with fractures filled with cross-fiber chrysotile constitute the ore that is mined at present.
Using the NO2/NOx Ratio to Understand the Spatial Heterogeneity of Secondary Pollutant Formation Capacity in Urban Atmospheres
NASA Astrophysics Data System (ADS)
Rao, M.; George, L. A.
Urban atmospheres are chemically reactive environments in which anthropogenic emissions can react with natural and anthropogenic components, on time scales of seconds to days, to increase the oxidative potential of the urban atmosphere and to create secondary air pollutants. The oxides of nitrogen (NOx = NO + NO2) are generated by combustion activities, including power plants and vehicles. Tailpipe emissions of NOx contain 10-20% NO2, and 90-80% NO. NO can be oxidized to NO2 by O3, HO2 and RO2species. The latter oxidants can be produced through the photo-oxidation of VOCs. It is likely then that oxidative capacity within a city is spatially heterogeneous since the distribution of anthropogenic (NOx, VOCs) and biogenic (VOCs) emissions varies spatially within the city. The spatial heterogeneity in local oxidative capacity of the urban atmosphere has seldom been measured or modeled at the fine spatial scale of ~250m. In summer 2013 we measured NO and NO2 using passive samplers over two weeks at 144 sites in the Portland Metro area. We used the ratio of NO2 to NOx as an indicator of the local atmospheric oxidative potential. We found the measured percentage of NO2 in NOx ranged from a minimum of 20% to a maximum of 76%, with an average value of 54% (std dev = 12%). The measured NO2/NOx ratio was statistically significantly correlated with both freeways and tree canopy within 250m (r = -0.25 and 0.31 respectively), showing a decreasing fraction of NO2 with increasing length of freeway and an increasing fraction of NO2in areas with greater tree cover, as expected. We will use the NO2 measurements to allocate county-level emissions to the spatial scale of ~250m for the Portland Metro area. Using WRF-Chem, we will then model the urban chemistry at this fine spatial scale, and compare the modeled NO to measured NO. Comparing the modeled and measured NO values will serve a dual purpose: it will help validate the fine spatial-scale WRF-Chem model for Portland, and it will provide an insight into the effectiveness of using the NO2/NOx ratio as an indicator of the potential for urban secondary pollutant formation.
NSDL National Science Digital Library
This webpage of the United States Geological Survey (USGS) and National Park Service (NPS) describes the geology and features of caves. It discusses cave formation, features, minerals found in caves, uses of caves, and various investigations of caves. There is an educational activity on karst topography formation, and links for additional information.
Geologic and climatic controls on the formation of the Permian coal measures in the Sohagpur coal field, Madhya Pradesh, India
Milici, R.C.; Warwick, P.D.; Mukhopadhyah, A.; Adhikari, S.; Roy, S.P.; Bhattacharyya, S.
The U.S. Geological Survey (USGS) and the Geological Survey of India (GSI) are concluding a cooperative study of the coking coal deposits in the Sohagpur coal field in central India. Because of the importance of coal in India's economy, the Coal Wing of the Geological Survey of India has studied the area intensely since the early 1980's. This report summarizes the overall stratigraphic, tectonic, and sedimentologic framework of the Sohagpur coal field area, and the interpretations of the geologic and climatic environments required for the accumulation of the thick Gondwana coal deposits, both coking and non-coking.
A Study of the Geology of the Rocks of the Huntington Formation in the Izee and Olds Ferry Terrains of the Blue Mountains Region
NSDL National Science Digital Library
This winning entry in the museum's Young Naturalist Awards 1999 by Matthew, a 17 year old student from Idaho, takes a look at the geology of the rocks of the Huntington Formation. His essay discusses the hypothetical series of events that explains how the Izee and Olds Ferry terrains were formed over hundreds of millions of years, the 10 rock specimens he collected there and the metamorphoses they have each undergone.
Applicability of the geological strength index (GSI) classification for very weak and sheared rock masses. The case of the Athens Schist Formation
E. Hoek; P. Marinos; M. Benissi
The Athens Schist Formation includes a wide variety of metasedimentary rocks, varying from strong or medium strong rocks\\u000a such as sericite metasandstone, limestone, greywacke, sericite schist through to weak rocks such as metasiltstone, clayey\\u000a and silty shale and phyllite. The overall rock mass is highly heterogeneous and anisotropic owing to the combined effect of\\u000a advanced weathering and severe tectonic stressing
Dispersion measurement as a method of quantifying geologic characterization and defining reservoir heterogeneity. Annual report, July 12, 1990--September 12, 1991
Menzie, D.E.
Since reservoirs are heterogeneous, nonuniform, and anisotropic, the success or failure of many enhanced oil recovery techniques rests on our prediction of internal variability and the paths of fluid flow in the reservoir. The main objective of this project is to develop a greater understanding of reservoir heterogeneities through dispersion measurement. In this annual report, an approach to ways to estimate the dispersivities of reservoir rocks from well logs is presented. From a series of rock property measurements and dispersion tests the following studies have been made: A measure of rock heterogeneity is developed by using the effluent concentration at one pore volume injection in a matched viscosity miscible displacement. By this approach, a heterogeneity factor is determined from the measured S-shaped dispersion curve. The parameter f in the Coats-Smith capacitance model is redefined as the dispersion fraction f{sub d} (or mechanical mixing fraction). At the f{sub d} pore volume injection, the dynamic miscible displacement efficiency reaches maximum. Reflected on the dispersion curve, this number corresponds to the peak of the first derivative of concentration. With the concept of dispersion fraction, a unique solution to the capacitance model is obtained, and then an equivalent dispersivity is defined. Through experimental data on Berea and Brown sandstone samples, it has been found that the equivalent dispersivity is an exponential function of the heterogeneity factor and can be used as a reservoir characteristic. Through a key parameter of tortuosity, dispersivity is related to rock petrophysical properties. This semi-theoretical relationship forms the basis for determining dispersivities from well logs. The approach is validated through experimental studies on Berea and Brown sandstone samples. It has been found that the equivalent dispersivity is an exponential function of the heterogeneity factor and can be used as a reservoir characteristic.
Amazonis Planitia: The role of geologically recent volcanism and sedimentation in the formation of the smoothest plains on Mars
NASA Astrophysics Data System (ADS)
Fuller, Elizabeth R.; Head, James W.
Amazonis Planitia, located between the two main volcanic provinces on Mars (Tharsis and Elysium), is characterized by extremely smooth topography at several scale lengths, as smooth as oceanic abyssal plains topography on Earth. We use Mars Global Surveyor (MGS) data (primarily very high resolution Mars Orbiter Laser Altimeter (MOLA) topography and derivative slope maps, gradient maps, and detrended maps) to examine the surface morphology of Amazonis Planitia and the stratigraphic relationships among previously mapped and newly defined units. These new data reveal the presence of a 1300 km diameter Noachian impact basin in northwest Amazonis Planitia and an extensive Late Hesperian lava flow unit that appears to have originated from the Olympus Mons source area prior to aureole formation. The presence of this previously unrecognized flow unit strongly suggests that Olympus Mons activity dates back to at least the Hesperian, as did activity on the Tharsis Montes. Emplacement of this ~100 meter thick flow unit formed a barrier along the northern margin of Amazonis Planitia which had a profound influence on the subsequent geologic history of the region. Formation of Olympus Mons aureole deposits created an eastern topographic barrier, and subsequent Tharsis Montes lava flows entered the basin from the south, flowing around the aureole. These three barriers (degraded Noachian crater rim, proto-Olympus Mons flow unit, and Olympus Mons aureole) caused subsequent lava flows and outflow channel effluents, primarily from the Elysium region to the west, to pond on the floor of Amazonis Planitia, preferentially smoothing the terrain there. Mars Orbiter Camera (MOC) images substantiate that at least two very fluid lava flows alternated with fluvial episodes from Elysium Planitia, flowing through Marte Valles onto the floor of the Amazonis Planitia basin. Within Amazonis Planitia, MOC images show flow-like textures heavily mantled by sediments, and radar data reveal the presence of rough lava flow surfaces underlying the sedimentary debris. These data thus suggest that the unique smoothness of Amazonis Planitia is the result of deposition of thin fluid lava flows and fluvial sediments in an enclosed basin. Crater counts suggest that the most recent resurfacing may have occurred in the latest Amazonian Period, in the last 1% of the history of Mars. In light of its unique history, it is somewhat ironic to note that Amazonis Planitia was originally thought to be a typical young Martian surface and therefore used to name the Amazonian era.
Ernest A. Mancini
The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 1 of the project has been reservoir description and characterization. This effort has included four tasks: (1) geoscientific reservoir characterization, (2) the study of rock-fluid interactions, (3) petrophysical and engineering characterization and (4) data integration. This work was scheduled for completion in Year 1. Overall, the project work is on schedule. Geoscientific reservoir characterization is essentially completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions has been initiated. Observations regarding the diagenetic processes influencing pore system development and heterogeneity in these reef and shoal reservoirs have been made. Petrophysical and engineering property characterization is progressing. Data on reservoir production rate and pressure history at Appleton and Vocation Fields have been tabulated, and porosity data from core analysis has been correlated with porosity as observed from well log response. Data integration is on schedule, in that, the geological, geophysical, petrophysical and engineering data collected to date for Appleton and Vocation Fields have been compiled into a fieldwide digital database for reservoir characterization, modeling and simulation for the reef and carbonate shoal reservoirs for each of these fields.
Geology of Brunei deltas, exploration status updated
Schreurs, J. [Brunei Shell Petroleum Co.Sdn. Bhd., Seria (Brunei Darussalam)
This article summarizes the petroleum geology of Negara Brunei Darussalam, the smallest but oil and gas richest country in Northwest Borneo. The paper describes the exploration history, Brunei geology, structural geology, main hydrocarbon reservoirs, seals, formation pressures, and current exploration.
A model of the Quaternary geological deposits of Bucharest City
NASA Astrophysics Data System (ADS)
Serpescu, Irina; Radu, Emil; Radu Gogu, Constantin; Amine Boukhemacha, Mohamed; Gaitanaru, Dragos; Bica, Ioan
Bucharest city is located in the central part of the Moesic Platform, in the Romanian Plain with micro-relief resulting from erosion and sedimentary processes which extended along the valleys of the Dambovita River to the south and the Colentina River to the north. The city is located in the axial area of a syncline where the thickness of the sedimentary deposits is up to 1000 m. The area lies on a rigid base is made of metamorphites, and various igneous intrusions (granodiorite, granite). The sedimentary deposits covering this rigid base are made by different phases of erosion and sedimentary processes of marine, lacustrian or continental sediments ending with Quaternary sediments. As a result, different alluvial deposits (such as piedmont, deltaic, alluvial cones, terrace, waterside and lacustrine deposits) can be met. Furthermore one also can find loess deposits which in turn cover totally the older deposits where rivers dug the present relief. To highlight the spatial extent of these geological structures, a geological model of Bucharest city is developed. A set of information coming from different sources as geological and geotechnical boreholes showing a detailed geological and lithological description, geological and topographical maps, geological and hydrogeological reports have been used to develop the 3D geological model of this region. 33 geological cross sections were defined and interpreted by using lithological and sedimentological criteria. Using these geological cross sections and prior geological knowledge, the Quaternary deposits have been described and classified into 6 structural units given from top to down as follows: (1) Superficial deposits represented by loess and anthropogenic materials. The geological model indicates that these deposits show a sporadic development becoming more concentrated in the central west part of the city. (2) Colentina Formations composed by of poorly sorted, cross-stratified sand and gravel with clayey lens indicating a high energy deposition environment. The geological model indicates more accentuate vertical lithological heterogeneity than a horizontal one as well as a decrease of the Colentina Formation thickness. (3) Intermediary deposits represented by silty-clay with fine sand intercalation indicating a mixed regime with limited lakes and dry lands. (4) Mostistea Formation made of sediments with a variety of grain size, from fine sand to coarse sand with small intercalations of gravels and scrap of woods. It was found that areas where the Intermediary deposits are less developed making the Colentina Formation in direct connection to Mostistea Formation. (5) Marly Complex composed by a succession of marls and clays with lenticular sandy intercalations indicating a fluvial-lacustrine environment. (6) Fratesti Strata made of sand and gravel which includes A, B and C Fratesti levels.
Geology of the Early Arikareean Sharps Formation on the Pine Ridge Indian Reservation and Surrounding Areas of South Dakota and Nebraska
McConnell, Thomas H.; DiBenedetto, Joseph N.
Based on geologic mapping, measured sections, and lithologic correlations, the local features of the upper and lower type areas of the Early Arikareean (30.8¢20.6 million years ago) Sharps Formation are revised and correlated. The Sharps Formation above the basal Rockyford Member is divided into two members of distinct lithotypes. The upper 233 feet of massive siltstones and sandy siltstones is named the Gooseneck Road Member. The middle member, 161 feet of eolian volcaniclastic siltstones with fluvially reworked volcaniclastic lenses and sandy siltstone sheets, is named the Wolff Camp Member. An ashey zone at the base of the Sharps Formation is described and defined as the Rockyford Ash Zone (RAZ) in the same stratigraphic position as the Nonpareil Ash Zone (NPAZ) in Nebraska. Widespread marker beds of fresh water limestones at 130 feet above the base of the Sharps Formation and a widespread reddish-brown clayey siltstone at 165 feet above the base of the Sharps Formation are described. The Brown Siltstone Beds of Nebraska are shown to be a southern correlative of the Wolff Camp Member and the Rockyford Member of the Sharps Formation. Early attempts to correlate strata in the Great Plains were slow in developing. Recognition of the implications of the paleomagnetic and lithologic correlations of this paper will provide an added datum assisting researchers in future biostratigraphic studies. Based on similar lithologies, the Sharps Formation, currently assigned to the Arikaree Group, should be reassigned to the White River Group. PMID:23110098
Geology of the Early Arikareean sharps formation on the Pine Ridge Indian Reservation and surrounding areas of South Dakota and Nebraska.
McConnell, Thomas H; Dibenedetto, Joseph N
Based on geologic mapping, measured sections, and lithologic correlations, the local features of the upper and lower type areas of the Early Arikareean (30.8-20.6 million years ago) Sharps Formation are revised and correlated. The Sharps Formation above the basal Rockyford Member is divided into two members of distinct lithotypes. The upper 233 feet of massive siltstones and sandy siltstones is named the Gooseneck Road Member. The middle member, 161 feet of eolian volcaniclastic siltstones with fluvially reworked volcaniclastic lenses and sandy siltstone sheets, is named the Wolff Camp Member. An ashey zone at the base of the Sharps Formation is described and defined as the Rockyford Ash Zone (RAZ) in the same stratigraphic position as the Nonpareil Ash Zone (NPAZ) in Nebraska. Widespread marker beds of fresh water limestones at 130 feet above the base of the Sharps Formation and a widespread reddish-brown clayey siltstone at 165 feet above the base of the Sharps Formation are described. The Brown Siltstone Beds of Nebraska are shown to be a southern correlative of the Wolff Camp Member and the Rockyford Member of the Sharps Formation. Early attempts to correlate strata in the Great Plains were slow in developing. Recognition of the implications of the paleomagnetic and lithologic correlations of this paper will provide an added datum assisting researchers in future biostratigraphic studies. Based on similar lithologies, the Sharps Formation, currently assigned to the Arikaree Group, should be reassigned to the White River Group. PMID:23110098
Geology, geochemistry, and age of volcanites of the Tunguda Volcanic Formation: The problem of the Archean-Proterozoic boundary in North Karelia
NASA Astrophysics Data System (ADS)
Myskova, T. A.; Ivanov, N. M.; Korsakova, M. A.; Mil'kevich, R. I.; Berezhnaya, N. G.; Presnyakov, S. L.
The geological, geochemical, and isotopic-geochronological data obtained for Sumian moderate-basic metavolcanites of Shombozero and Lekhta structures of the Panayarvi-Vygozero belt shows that the Tunguda Formation is confined to the Paleoproterozoic structural and material complex. This formation is represented by the complex of weakly differentiated andesitobasalts and andesites of calc-alkaline series with higher contents of MgO and moderate contents of Al2O3 and rare earth elements. The rocks of the Tunguda Formation are different from the Late Archean basic rocks of the Hiziyarvi Formation represented mainly by tholeiitic basalts with low REE contents and undifferentiated spectrum of REE distribution. The age of volcanites of the Tunguda Formation was determined to be 2439 ▒ 21 Ma. The xenogenic zircons from metaandesites of the Tunguda Formation have Neoarchean age according to the 207Pb/206Pb ratio (from 2536 ▒ 4 to 2825 ▒ 7 Ma). The Neoarchean zircons, a negative value of ?Nd (-3.8), and indicative geochemical parameters are evidence that the crustal component took part in formation of the protolith of the studied rocks.
NSDL National Science Digital Library
Russell Graymer
This web site provides an introduction to geologic maps. Topics covered include what is a geologic map, unique features of geologic maps, letter symbols, faults, and strike and dip. Users may click to view colored geologic maps, the geologic map of the United States and the geologic relief map of the United States.
Formation of nitro-PAHs from the heterogeneous reaction of ambient particle-bound PAHs with N2O5/NO3/NO2
Zimmermann, Kathryn; Jariyasopit, Narumol; Massey Simonich, Staci L.; Tao, Shu; Atkinson, Roger; Arey, Janet
Reactions of ambient particles collected from four sites within the Los Angeles, CA air basin and Beijing, China with a mixture of N2O5, NO2, and NO3 radicals were studied in an environmental chamber at ambient pressure and temperature. Exposures in the chamber system resulted in the degradation of particle-bound PAHs and formation of molecular weight (mw) 247 nitropyrenes (NPYs) and nitrofluoranthenes (NFLs), mw 273 nitrotriphenylenes (NTPs), nitrobenz[a]anthracenes (NBaAs), and nitrochrysene (NCHR), and mw 297 nitrobenzo[a]pyrene (NBaP). The distinct isomer distributions resulting from exposure of filter-adsorbed deuterated fluoranthene to N2O5/NO3/NO2 and that collected from the chamber gas-phase suggest that formation of NFLs in ambient particles did not occur by NO3 radical-initiated reaction, but from reaction of N2O5, presumably subsequent to its surface adsorption. Accordingly, isomers known to result from gas-phase radical-initiated reactions of parent PAHs, such as 2-NFL and 2- and 4-NPY, were not enhanced from the exposure of ambient particulate matter to N2O5/NO3/NO2. The reactivity of ambient particles toward nitration by N2O5/NO3/NO2, defined by relative 1-NPY formation, varied significantly, with the relative amounts of freshly emitted particles versus aged particles (particles that had undergone atmospheric chemical processing) affecting the reactivity of particle-bound PAHs toward heterogeneous nitration. Analyses of unexposed ambient samples suggested that, in nighttime samples where NO3 radical-initiated chemistry had occurred, heterogeneous formation of 1-NPY on ambient particles may have contributed to the ambient 1-NPY concentrations at downwind receptor sites. These results, together with observations that 2-NFL is consistently the dominant particle-bound nitro-PAH measured in ambient atmospheres, suggest that for PAHs that exist in both the gas- and particle-phase, the heterogeneous formation of particle-bound nitro-PAHs is a minor formation route compared to gas-phase formation. PMID:23865889
Formation of nitro-PAHs from the heterogeneous reaction of ambient particle-bound PAHs with N2O5/NO3/NO2.
Zimmermann, Kathryn; Jariyasopit, Narumol; Massey Simonich, Staci L; Tao, Shu; Atkinson, Roger; Arey, Janet
Reactions of ambient particles collected from four sites within the Los Angeles, CA air basin and Beijing, China with a mixture of N2O5, NO2, and NO3 radicals were studied in an environmental chamber at ambient pressure and temperature. Exposures in the chamber system resulted in the degradation of particle-bound PAHs and formation of molecular weight (mw) 247 nitropyrenes (NPYs) and nitrofluoranthenes (NFLs), mw 273 nitrotriphenylenes (NTPs), nitrobenz[a]anthracenes (NBaAs), nitrochrysene (NCHR), and mw 297 nitrobenzo[a]pyrene (NBaP). The distinct isomer distributions resulting from exposure of filter-adsorbed deuterated fluoranthene to N2O5/NO3/NO2 and that collected from the chamber gas-phase suggest that formation of NFLs in ambient particles did not occur by NO3 radical-initiated reaction but from reaction of N2O5, presumably subsequent to its surface adsorption. Accordingly, isomers known to result from gas-phase radical-initiated reactions of parent PAHs, such as 2-NFL and 2- and 4-NPY, were not enhanced from the exposure of ambient particulate matter to N2O5/NO3/NO2. The reactivity of ambient particles toward nitration by N2O5/NO3/NO2, defined by relative 1-NPY formation, varied significantly, with the relative amounts of freshly emitted particles versus aged particles (particles that had undergone atmospheric chemical processing) affecting the reactivity of particle-bound PAHs toward heterogeneous nitration. Analyses of unexposed ambient samples suggested that, in nighttime samples where NO3 radical-initiated chemistry had occurred, heterogeneous formation of 1-NPY on ambient particles may have contributed to the ambient 1-NPY concentrations at downwind receptor sites. These results, together with observations that 2-NFL is consistently the dominant particle-bound nitro-PAH measured in ambient atmospheres, suggest that for PAHs that exist in both the gas- and particle-phase, the heterogeneous formation of particle-bound nitro-PAHs is a minor formation route compared to gas-phase formation. PMID:23865889
NASA Technical Reports Server (NTRS)
Woronow, A. (editor)
Advances in Planetary Geology is a new series intended to serve the planetary geology community with a form for quick and thorough communications. There are no set lists of acceptable topics or formats, and submitted manuscripts will not undergo a formal review. All submissions should be in a camera ready form, preferably spaced, and submitted to the editor.
Formation of nitro-PAHs from the heterogeneous reaction of ambient particle-bound PAHs with NO3/N2O5
NASA Astrophysics Data System (ADS)
Zimmermann, K.; Jariyasopit, N.; Simonich, S. L.; Atkinson, R.; Arey, J.
Polycyclic aromatic hydrocarbons (PAHs) and their nitrated derivatives (nitro-PAHs) have been shown to be mutagenic in bacterial and mammalian assays and are classified as probable human carcinogens. Semi-volatile PAHs partition between the gas and particulate phases, depending on their liquid-phase vapor pressures and ambient temperatures. These PAHs have been extensively measured in ambient particulate matter and can ultimately undergo long-range transport from source regions (e.g., China to the western USA) (1). During transport these particle-bound PAHs may undergo reaction with NO3/N2O5 to form nitro-PAH derivatives. Previous studies of heterogeneous nitration of PAHs have used particles composed of graphite, diesel soot, and wood smoke (2-4). This study investigates the heterogeneous formation of nitro-PAHs from ambient particle-bound PAHs from Beijing, China and sites located within the Los Angeles air basin. These ambient particle samples, along with filters coated with isotopically labeled PAHs, were exposed to a mix of NO2/NO3/N2O5 in a 7000 L Teflon chamber, with analysis focused on the heterogeneous formation of molecular weight 247 and 273 nitro-PAHs. The heterogeneous formation of certain nitro-PAHs (including1-nitropyrene and 1- and 2-nitrotriphenylene) was observed for some, but not all, ambient samples. Formation of nitro-PAHs typically formed through gas-phase reactions (2-nitrofluoranthene and 2-nitropyrene) was not observed. The effect of particle age and local photochemical conditions during sampling on the degree of nitration in environmental chamber reactions, as well as ambient implications, will be presented. 1. Primbs, T.; Simonich, S.; Schmedding, D.; Wilson, G.; Jaffe, D.; Takami, A.; Kato, S.; Hatakeyama, S.; Kajii, Y. Environ. Sci. Technol. 2007, 41, 3551-3558. 2. Esteve, W.; Budzinski, H.; Villenave, E. Atmospheric Environment 2004, 38, 6063-6072. 3. Nguyen, M.; Bedjanian, Y.; Guilloteau, A. Journal of Atmospheric Chemistry 2009, 62, 139-150. 4. Kamens, R. M.; Zhi-Hua, F.; Yao, Y.; Chen, D.; Chen, S.; Vartiainen, M. Chemosphere 1994, 28, 1623-1632.
Methods and apparatus for measurement of the resistivity of geological formations from within cased wells in presence of acoustic and magnetic energy sources
Vail, III, William B. (Bothell, WA)
Methods and apparatus are provided for measuring the acoustically modulated electronic properties of geological formations and cement layers adjacent to cased boreholes. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. Voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of the leakage current conducted into formation in the vicinity of those electrodes. Simultaneously subjecting the casing and formation to an acoustic source acoustically modulates the leakage current measured thereby providing a measure of the acoustically modulated electronic properties of the adjacent formation. Similarly, methods and apparatus are also described which measure the leakage current into formation while simultaneously subjecting the casing to an applied magnetic field which therefore allows measurement of the magnetically modulated electronic properties of the casing and the adjacent formation.
Geologic and hydrologic controls on the occurrence and producibility of coalbed methane, Fruitland Formation, San Juan Basin. Topical report, August 1987-July 1990
Ayers, W.B.; Kaiser, W.R.; Laubach, S.E.; Ambrose, W.A.; Baumgardner, R.W.
Coalbed methane resources in the Fruitland Formation of the San Juan Basin are estimated to be between 43 and 49 trillion cubic feet (Tcf). The technology required to exploit the resource is in the developmental stage; the goal of the study was to relate coalbed methane occurrence and producibility to geologic and hydrologic settings, leading to models for exploration and production. The models developed in the study should reduce the cost of exploration, optimize production of the large unconventional energy resource, and ensure a supply of natural gas at a reasonable cost.
NSDL National Science Digital Library
National Park Service (NPS)
This site from the National Park Service briefly addresses the geology of Devil's Tower. The evolution of various theories on the formation of the tower are discussed. A slide show of the emplacement of the tower is also available.
NSDL National Science Digital Library
This map displays the sedimentary rocks of the Cenozoic, Mesozoic, and Paleozoic eras as well as the igneous and metamorphic rocks of the Mesozoic and Precambrian eras. There is a pagesize copy of the geologic map, a brief description of the geology and physiographic provinces of New Jersey, and information on bedrock geologic maps of New Jersey (in CD-ROM format).
Characterization of Pliocene and Miocene Formations in the Wilmington Graben, Offshore Los Angeles, for Large-Scale Geologic Storage of CO2
Bruno, Michael
Geomechanics Technologies has completed a detailed characterization study of the Wilmington Graben offshore Southern California area for large-scale CO2 storage. This effort has included: an evaluation of existing wells in both State and Federal waters, field acquisition of about 175 km (109 mi) of new seismic data, new well drilling, development of integrated 3D geologic, geomechanics, and fluid flow models for the area. The geologic analysis indicates that more than 796 MMt of storage capacity is available within the Pliocene and Miocene formations in the Graben for midrange geologic estimates (P50). Geomechanical analyses indicate that injection can be conducted without significant risk for surface deformation, induced stresses or fault activation. Numerical analysis of fluid migration indicates that injection into the Pliocene Formation at depths of 1525 m (5000 ft) would lead to undesirable vertical migration of the CO2 plume. Recent well drilling however, indicates that deeper sand is present at depths exceeding 2135 m (7000 ft), which could be viable for large volume storage. For vertical containment, injection would need to be limited to about 250,000 metric tons per year per well, would need to be placed at depths greater than 7000ft, and would need to be placed in new wells located at least 1 mile from any existing offset wells. As a practical matter, this would likely limit storage operations in the Wilmington Graben to about 1 million tons per year or less. A quantitative risk analysis for the Wilmington Graben indicate that such large scale CO2 storage in the area would represent higher risk than other similar size projects in the US and overseas.
Geologic assessment of undiscovered oil and gas resources: Oligocene Frio and Anahuac Formations, United States Gulf of Mexico coastal plain and State waters
Swanson, Sharon M.; Karlsen, Alexander W.; Valentine, Brett J.
The Oligocene Frio and Anahuac Formations were assessed as part of the 2007 U.S. Geological Survey (USGS) assessment of Tertiary strata of the U.S. Gulf of Mexico Basin onshore and State waters. The Frio Formation, which consists of sand-rich fluvio-deltaic systems, has been one of the largest hydrocarbon producers from the Paleogene in the Gulf of Mexico. The Anahuac Formation, an extensive transgressive marine shale overlying the Frio Formation, contains deltaic and slope sandstones in Louisiana and Texas and carbonate rocks in the eastern Gulf of Mexico. In downdip areas of the Frio and Anahuac Formations, traps associated with faulted, rollover anticlines are common. Structural traps commonly occur in combination with stratigraphic traps. Faulted salt domes in the Frio and Anahuac Formations are present in the Houston embayment of Texas and in south Louisiana. In the Frio Formation, stratigraphic traps are found in fluvial, deltaic, barrier-bar, shelf, and strandplain systems. The USGS Tertiary Assessment Team defined a single, Upper Jurassic-Cretaceous-Tertiary Composite Total Petroleum System (TPS) for the Gulf Coast basin, based on previous studies and geochemical analysis of oils in the Gulf Coast basin. The primary source rocks for oil and gas within Cenozoic petroleum systems, including Frio Formation reservoirs, in the northern, onshore Gulf Coastal region consist of coal and shale rich in organic matter within the Wilcox Group (Paleocene¢Eocene), with some contributions from the Sparta Sand of the Claiborne Group (Eocene). The Jurassic Smackover Formation and Cretaceous Eagle Ford Formation also may have contributed substantial petroleum to Cenozoic reservoirs. Modeling studies of thermal maturity by the USGS Tertiary Assessment Team indicate that downdip portions of the basal Wilcox Group reached sufficient thermal maturity to generate hydrocarbons by early Eocene; this early maturation is the result of rapid sediment accumulation in the early Tertiary, combined with the reaction kinetic parameters used in the models. A number of studies indicate that the migration of oil and gas in the Cenozoic Gulf of Mexico basin is primarily vertical, occurring along abundant growth faults associated with sediment deposition or along faults associated with salt domes. The USGS Tertiary assessment team developed a geologic model based on recurring regional-scale structural and depositional features in Paleogene strata to define assessment units (AUs). Three general areas, as described in the model, are found in each of the Paleogene stratigraphic intervals assessed: ōStable Shelf,ö ōExpanded Fault,ö and ōSlope and Basin Floorö zones. On the basis of this model, three AUs for the Frio Formation were defined: (1) the Frio Stable Shelf Oil and Gas AU, containing reservoirs with a mean depth of about 4,800 feet in normally pressured intervals; (2) the Frio Expanded Fault Zone Oil and Gas AU, containing reservoirs with a mean depth of about 9,000 feet in primarily overpressured intervals; and (3) the Frio Slope and Basin Floor Gas AU, which currently has no production but has potential for deep gas resources (>15,000 feet). AUs also were defined for the Hackberry trend, which consists of a slope facies stratigraphically in the middle part of the Frio Formation, and the Anahuac Formation. The Frio Basin Margin AU, an assessment unit extending to the outcrop of the Frio (or basal Miocene), was not quantitatively assessed because of its low potential for production. Two proprietary, commercially available databases containing field and well production information were used in the assessment. Estimates of undiscovered resources for the five AUs were based on a total of 1,734 reservoirs and 586,500 wells producing from the Frio and Anahuac Formations. Estimated total mean values of technically recoverable, undiscovered resources are 172 million barrels of oil (MMBO), 9.4 trillion cubic feet of natural gas (TCFG), and 542 million barrels of natural gas liquids for all of the Frio and Anahuac AUs. Of the five units asse
Reservoir Characterization, Formation Evaluation, and 3D Geologic Modeling of the Upper Jurassic Smackover Microbial Carbonate Reservoir and Associated Reservoir Facies at Little Cedar Creek Field, Northeastern Gulf of MexicoĀ
Al Haddad, Sharbel
A Thesis by SHARBEL SALAM AL HADDAD Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved by: Chair of Committee, Ernest A.... Mancini Committee Members, Michael C. Pope Michael J. King Head of Department, John R. Giardino August 2012 Major Subject: Geology iii iii ABSTRACT Reservoir Characterization, Formation Evaluation, and 3D Geologic Modeling...
Physical Characteristics, Geologic Setting, and Possible Formation Processes of Spring Deposits on Mars Based on Terrestrial Analogs
NASA Technical Reports Server (NTRS)
Crumpler, L. S.
Spring formation is a predicted consequence of the interaction of former Martian aquifers with structures common to Mars, including basin margins, Tharsis structures, and other structural deformation characteristics. The arid environment and high abundance of water soluble compounds in the crust will have likewise encouraged spring deposit formation at spring sites. Such spring deposits may be recognized from morphological criteria if the characteristics of formation and preservation are understood. An important first step in the current Mars exploration strategy [10] is the detection of sites where there is evidence for past or present near-surface water on Mars. This study evaluates the large-scale morphology of spring deposits and the physical processes of their formation, growth, and evolution in terms that relate to (1) their identification in image data, (2) their formation, evolution, and preservation in the environment of Mars, and (3) their potential as sites of long-term or late stage shallow groundwater emergence at the surface of Mars.
An integrated multi-scale hydrogeological model for performance and safety assessment of French geological high level and long live radwaste disposal in clay formation
NASA Astrophysics Data System (ADS)
Benabderrahmane, H.; Cornaton, F. J.; Kerrou, J.
A deep geological repository of high level and long live radwaste requires sound understanding of the far field and near field groundwater flow and transport properties. Andra, French National radioactive waste management Agency is developing since last 15 years, an integrated multi-scale hydrogeological model of whole Paris basin of 200'000 Km2 area (regional scale) to produce a regional flow field associated to groundwater behavior. It includes locally the Meuse / Haute Marne clay site of about 250 Km2 area in the eastern part of Paris basin that was chosen for the emplacement of a repository. Callovo-Oxfordian as host formation is a clay layer characterized by very low permeability, a mean thickness of 130 m at about 500 m depth and is embedded by calcareous formations as aquifers (Dogger and Oxfordian). The hydrogeological conceptual model is based on stratigraphic and petrophysic modeling of the Paris basin and is accounting for the sound structural, geological, hydrogeological and geochemical data in an integrated way. At Paris basin scale, the model is a multilayer system of 27 layers (hydrogeological units) from Trias to Tertiary. A refinement at local scale of the site defines 27 hydro-geological units from Trias to Portlandian within an area of 1800 Km2. Based on sound data acquisition from borehole and seismic campaigns performed by Andra, regional faults, minor and diffuse fractures are considered. A structural and petrophysical representation of the transition zone between the Paris basin scale and site scale, as well as a better handling of surface flow boundary conditions are considered. Finite element flow and transport simulator Ground Water code (GW) is used to solve for groundwater flow at steady-state in a 1.8 Million nodes model, considering current climatic conditions. The model is calibrated against about 1250 hydraulic head measurements, and results in maximum absolute hydraulic head differences of 20 meters at the regional scale and 5 meters at the local scale. The calibrated reference model includes transmissive major faults as well as structures acting as barrier to flow. Advective-dispersive age solutions are also carried out and compared to available age dates of pore water within the two main calcareous aquifers (Dogger and Oxfordian) that embed Callovo-Oxfordian host formation, to consolidate calibration of flow and to analyze internal water mixing processes and hydraulic behavior of major faults. Lifetime expectancy solutions combined with age solutions are also used to map in the 3-D space the low- and high-speed flow zones at the local scale.
Geological summary of the Busidima Formation (Plio-Pleistocene) at the Hadar paleoanthropological site, Afar Depression, Ethiopia.
Campisano, Christopher J
The Hadar paleoanthropological site in Ethiopia preserves a record of hominin evolution spanning from approximately 3.45 Ma to 0.8 Ma. An angular unconformity just above the ca. 2.95 Ma BKT-2 complex divides the sediments into the Hadar Formation (ca. 3.8-2.9Ma) and the Busidima Formation (ca. 2.7-0.15 Ma). The unconformity is likely a response to a major tectonic reorganization in the Afar Depression, and activation of the As Duma fault near the Ethiopian Escarpment (west of Hadar) created a half-graben in which the Busidima Formation was deposited. The pattern and character of sedimentation in the region changed dramatically above the unconformity, as cut-and-fill channel conglomerates and silt-dominated paleosols that comprise the Busidima Formation stand in sharp contrast to the underlying deposits of the Hadar Formation. Conglomerate deposition has been related to both the perennial, axial paleo-Awash and ephemeral, escarpment-draining tributaries. Overbank silts have yielded fossils attributed to early Homo and Oldowan stone tools. Numerous tuffaceous deposits exist within the Busidima Formation, but they are often spatially limited, fine-grained, and reworked. Recent work on the tephrostratigraphic framework of the Busidima Formation at Hadar has identified at least 12 distinct vitric tephras and established the first geochemical-based correlations between Hadar and the neighboring project areas of Gona and Dikika. Compared to Gona and Dikika, where Busidima Formation sediments are exposed over large areas, the highly discontinuous sediments at Hadar comprise less than 40 m in composite section and are exposed over an area of <20 km(2), providing only snapshots into the 2.7-0.15 Ma window. The stratigraphic record at Hadar confirms the complex depositional history of the Busidima Formation, and also provides important details on regional stratigraphic correlations and the pattern of deposition and erosion in the lower Awash Valley reflective of its tectonic history. PMID:21762952
NSDL National Science Digital Library
Geologic Maps are unique in that they show the distribution of geologic features on a landscape through specific symbols and colors. The United States Geological Survey's (USGS) site Geologic Maps provides visitors with a good introduction to these concepts, which include the unique features of a geologic map; the meaning of their lines, colors, and symbols; the location of faults; and more. Anyone working with geologic maps or just interested in learning a little about cartography or geology will find this site easy to explore and full of good information.
Permeability heterogeneity of the Palm Spring formation, Mecca Hills, California: Implications for fluvial-deltaic reservoir characterization
Kelty, T.K.; Yin, An [Univ. of California, Los Angeles, CA (United States)
Excellent exposures of the nonmarine, Pliocene to Pleistocene Palm Spring Formation allow the investigation of the spatial permeability variations. By sampling with a field permeameter, the permeability variations between and within sedimentary lithofacies, as well as effects of a major intraformational, angular unconformity on the permeability structure of the lower Palm Spring Formation are characterized. A systematic permeability distribution of the major lithofacies within the lower Palm Spring Formation is revealed by this work. The highest mean permeability is found in the coarse-grained matrix of conglomerates and the horizontally laminated and cross-bedded sandstones. The massive and rippled sandstones exhibit the lowest mean permeability. The three lithofacies that show the greatest variability about the mean are the conglomerates, horizontally laminated sandstones and massive sandstones. This study indicates that field observations of sedimentary features can be correlated with permeability variations in the Palm Spring Formation. Permeability data are utilized to estimate the correlation ranges over a horizontal distance of 500 meters within a sandstone bed. This analysis and field observations indicate that the correlation distance of permeability corresponds with the width of channels in the sandstone bed. Sampling of the Palm Spring Formation adjacent to an intraformational unconformity demonstrates that there is a decrease in permeability directly beneath the unconformity. This permeability reduction is due to secondary mineralization localized along the unconformity that possibly occurred during subaerial exposure.
Permeability heterogeneity of the Palm Spring formation, Mecca Hills, California: Implications for fluvial-deltaic reservoir characterization
Kelty, T.K.; Yin, An (Univ. of California, Los Angeles, CA (United States))
Excellent exposures of the nonmarine, Pliocene to Pleistocene Palm Spring Formation allow the investigation of the spatial permeability variations. By sampling with a field permeameter, the permeability variations between and within sedimentary lithofacies, as well as effects of a major intraformational, angular unconformity on the permeability structure of the lower Palm Spring Formation are characterized. A systematic permeability distribution of the major lithofacies within the lower Palm Spring Formation is revealed by this work. The highest mean permeability is found in the coarse-grained matrix of conglomerates and the horizontally laminated and cross-bedded sandstones. The massive and rippled sandstones exhibit the lowest mean permeability. The three lithofacies that show the greatest variability about the mean are the conglomerates, horizontally laminated sandstones and massive sandstones. This study indicates that field observations of sedimentary features can be correlated with permeability variations in the Palm Spring Formation. Permeability data are utilized to estimate the correlation ranges over a horizontal distance of 500 meters within a sandstone bed. This analysis and field observations indicate that the correlation distance of permeability corresponds with the width of channels in the sandstone bed. Sampling of the Palm Spring Formation adjacent to an intraformational unconformity demonstrates that there is a decrease in permeability directly beneath the unconformity. This permeability reduction is due to secondary mineralization localized along the unconformity that possibly occurred during subaerial exposure.
Inversion of synthetic geodetic data for dip-slip faults: clues to the effects of lateral heterogeneities and data distribution in geological environments typical of the Apennines (Italy)
NASA Astrophysics Data System (ADS)
Amoruso, A.; Barba, S.; Crescentini, L.; Megna, A.
The inversion of geodetic data to obtain earthquake parameters is often performed by assuming that the medium is isotropic, elastic and either homogeneous or layered. The layered medium often offers the best estimate of the structure of the crust; however, predicted displacements and observed data may differ beyond the measurement errors. The slip distribution on the fault plane is usually obtained by dividing the best uniform slipping fault into an arbitrarily large number of subfaults and minimizing a cost function that includes a smoothness (Laplacian) term and a data misfit term. The smoothing factor controls the trade-off between the smoothness and the goodness-of-fit. The main focus of this work is the determination and effect of the smoothing parameter. We conducted several inversion tests of noiseless synthetic surface displacement due to faults embedded in media with properties consistent with the geology of the Central Apennines (Italy), where the 2009 April 6, L'Aquila earthquake occurred. We used the following three-step procedure: (i) global optimization with no smoothness constraint for a fault divided into a small number of equally sized equal-rake subfaults; (ii) selection of the best fault parameters using information criteria and (iii) evaluation of the slip amplitude distribution on an expanded fault after choosing the smoothing factor from trade-off curves or from cross-validation for different numbers of subfaults. We show that all of the fault features obtained by the inversion procedure, including the slip distribution, agree with those (`true') used in the forward modelling when the data cover the majority of the displacement field. Notable departures from the true slip distribution occur when a suboptimal smoothing factor (obtained from the trade-off curves or cross-validation) is used. If different crustal stratifications are used in the inversions, the best results are obtained for the stratification that is the closest to the true crustal structure. When we use more realistic GPS distributions, prominent spurious slip patches can be obtained. Modellers should use synthetic tests and sensitivity analyses as an initial step in the data inversion for source parameters.
In previous publications (McMurry and Wilson, 1982; McMurry et al., 1981), techniques for determining the relative contributions of gas phase and liquid phase reactions to secondary ambient aerosol formation have been described. In this paper these methods are applied to more rec...
Measuring resistivity changes from within a first cased well to monitor fluids injected into oil bearing geological formations from a second cased well while passing electrical current between the two cased wells
Vail, III, William B. (Bothell, WA)
A.C. current is conducted through geological formations separating two cased wells in an oil field undergoing enhanced oil recovery operations such as water flooding operations. Methods and apparatus are disclosed to measure the current leakage conducted into a geological formation from within a first cased well that is responsive to fluids injected into formation from a second cased well during the enhanced oil production activities. The current leakage and apparent resistivity measured within the first cased well are responsive to fluids injected into formation from the second cased well provided the distance of separation between the two cased wells is less than, or on the order of, a Characteristic Length appropriate for the problem.
Uncertainties caused by the geological structure in hydrogeological modeling: Stochastic simulation of a heterogeneous glacial structure with emphasize on stationarity issues and the incorporation of borehole- and geophysical data.
NASA Astrophysics Data System (ADS)
Koch, Julian; He, Xin; Refsgaard, Jens C.; Jensen, Karsten H.
The heterogeneity of the geological structure causes uncertainties in hydrogeological investigations of groundwater flow and contaminant transport. Traditionally the best comprehensive knowledge is combined in order to create one model of the subsurface structure, often based on subjective interpretations and sparse data availability. Stochastic simulation methods address this problem by generating an ensemble of realizations of the geology, all of them equally plausible, because they honor available data and follow predefined geometrical attributes such as proportions and mean lengths. In this study the geostatistical software T-ProGS is utilized to simulate an ensemble of realizations for a binary (sand/clay) hydrofacies model in the Norsminde catchment, eastern Jutland, Denmark. Categorized borehole data and geophysical data (SkyTEM) indicate a variation of sand proportion within the model area. Therefore the model domain is subdivided into three independent and statistically stationary sub-model domains of different sand proportions and mean lengths. The sand proportion in the SkyTEM data depends on a cut-off value, separating the dataset into sand and clay. This cut-off value is manually calibrated by assuming the smallest deviation between the sand proportions in the borehole- and in the SkyTEM data in areas with a high sample density. The calibration yields an overall sand proportion of 23% with a cut-off value of 46 ?m. The stochastic simulations are conditioned against the available datasets with hard and soft conditioning. The category probabilities for the SkyTEM dataset are derived from a histogram approach, where resistivity is associated with corresponding lithology from the categorized borehole data. The boreholes are grouped in four quality groups, which are associated with trust scores, allowing soft conditioning. In total, 30 realizations are simulated for each sub-domain and for the entire domain. Ten simulations are selected by favoring minimal deviations between simulated and desired sand proportions. The simulations for the individual sub-domains produce more accurate results with respect to the sand proportion than the case where the entire domain is simulated altogether. However the variation in mean lengths in the sub-domains is not simulated correctly. Moreover, a split sample test indicates a significant gain in simulation accuracy, if SkyTEM data are incorporated. If only borehole data are used for conditioning, it simulates only 25% of the sand cells correctly.
Engineering geological characteristics and the hydraulic fracture propagation mechanism of the sand-shale interbedded formation in the Xu5 reservoir
NASA Astrophysics Data System (ADS)
Lu, Cong; Li, Mei; Guo, Jian-Chun; Tang, Xu-Hai; Zhu, Hai-Yan; Yong-Hui, Wang; Liang, Hao
In the Xu5 formation the sandstone reservoir and the shale reservoir are interbedded with each other. The average thickness of each formation is about 8?m, which increases the difficulty of the hydraulic fracturing treatment. The shale thickness ratio (the ratio of shale thickness to formation thickness) is 55¢62.5%. The reservoir is characterized by ultra-low porosity and permeability. The brittleness index of sandstone is 0.5¢0.8, and the brittleness index of shale is 0.3¢0.8. Natural fractures are poorly developed and are mainly horizontal and at a low angle. The formation strength is medium and the reservoir is of the hybrid strike-slip fault and reverse fault stress regime. The difference between the minimum principal stress and the vertical stress is small, and the maximum horizontal principal stress is 20?MPa higher than the minimum horizontal principal stress and vertical stress. A mechanical model of a hydraulic fracture encountering natural fractures is built according to geological characteristics. Fracture mechanics theory is then used to establish a hydraulic fracturing model coupling the seepage¢stress¢damage model to simulate the initiation and propagation of a fracture. The hydraulic fracture geometry is mainly I-shaped and T-shaped, horizontal propagation dominates the extension, and vertical propagation is limited. There is a two to three meter stress diversion area around a single hydraulic fracture. The stress diversion between a hydraulic fracture and a natural fracture is advantageous in forming a complex fracture. The research results can provide theoretical guidance for tight reservoir fracturing design.
The geological significance of the boundary between the Fort Sill and Signal Mountain Formations in the lower Arbuckle Group (Cambrian)
Hosey, R.; Donovan, R.N. (Texas Christian Univ., Ft Worth, TX (United States). Geology Dept.)
During the upper Cambrian, a transgression inundated the Southern Oklahoma aulacogen enveloping a landscape that consisted of hills of Cambrian-aged rhyolite up to 350 m in height. Initial deposits on this topography--the Reagan Formation--consist of siliciclastics that were deposited as alluvium and succeeding tidally-influenced marine sandstones and shales. The siliciclastics grains are made up of local rhyolite, quartz and authigenic glauconite. The overlying Honeycreek Formation is defined by the addition of carbonated detritus in the form of tidally-influenced pelmatozoan grainstones. The passage from the Honeycreek to the overlying Fort Sill Formation of the Arbuckle Group is marked by the incoming of beds of lime mudstone and the gradual disappearance of grainstones and siliciclastics. The contact between the Fort Sill and the overlying thinly-bedded dark grey bioclastic limestones of the Signal Mountain Formation is one of the most distinctive horizons in the Arbuckle Group. The contact evidently marks a substantial change in depositional environment. In detail the contact is sharp and shows evidence of minor erosion, although no karsting has been detected. The authors suggest that the contact surface records a regression, perhaps associated with dolomitization and followed by some erosion. A regression is also indicated by the local occurrence of a laminated tidal flat unit with traces of evaporites that outcrops in the far west of the Slick Hills immediately below the formation contact. They suggest that the Signal Mountains as a transgressive unit, incorporating siliciclastics transported into the area during the regression. It has been suggested that the unconformity reflects localized tectonism associated with the evolution of the Southern Oklahoma aulacogen. On the other hand the surface may correlate with a craton--wide Sauxian' hiatus.
Feldspathic Rock Spectral Detections on Mars: Geologic Context, Possible Formation Mechanisms, and the TES/Themis Perspective
NASA Astrophysics Data System (ADS)
Rogers, D.; Nekvasil, H.
Spectral detections from VNIR imaging spectrometers OMEGA and CRISM suggest feldspar-bearing rocks with <5% mafic minerals in restricted locations on Mars. The detections have been interpreted as anorthositic, or alternatively, felsic lithologies such as granite. The detections occur in a variety of contexts, including crater central peaks, walls, and floors, intercrater plains of Noachis Terra, and the Nili patera caldera floor. Here we focus on the Noachis Terra feldspathic rock detections, and present constraints from geologic context and complementary thermal infrared measurements. We also examine mechanisms for forming feldspar-rich lavas from crystal fractionation at the base of thick Martian crust. Noachis Terra exposures exhibit high thermal inertias and deep spectral contrast, consistent with competent, non-porous rock. They commonly overlie olivine basaltic bedrock and are ~20-25 m thick. THEMIS spectra from these units are inconsistent with quartz abundances > 5%, ruling out felsic compositions. THEMIS spectra are consistent with both anorthositic and basaltic lithologies; laboratory spectra of these lithologies are indistinguishable at THEMIS resolution. TES spectra do not match library anorthosites, with ~20-30% modeled pyroxene and ~5-10% olivine. Strong contribution from basaltic sediment to the TES spectra is unlikely given the deeper spectral contrast associated with the feldspathic units than underlying olivine basaltic bedrock. Future work will include spectral comparison with other low silica, feldspathic rocks to determine if there is an analog material that is consistent with both the VNIR and TIR observations. The geologic context of the Noachis units suggests volcanic, rather than plutonic origins, although shallow sills or subglacial eruptive units are possible. Previous experimental and modeling work by Nekvasil showed that feldspar-rich (up to 75 wt%), low-silica lavas may be produced from known Martian basalt by shallow crystallization of liquids residual to partial fractionation at the base of a thick Martian crust. The plagioclase fraction increases with both the extent and depth of fractionation. Given that Noachis Terra is associated with thick highlands crust, this mechanism would be a plausible explanation for feldspathic rock detections in this region.
National Geologic Map Database
NSDL National Science Digital Library
The National Geologic Map Database (NGMDB) is an Internet-based system for query and retrieval of earth-science map information, created as a collaborative effort between the USGS and the Association of American State Geologists. Its functions include providing a catalog of available map information; a data repository; and a source for general information on the nature and intended uses of the various types of earth-science information. The map catalog is a comprehensive, searchable catalog of all geoscience maps of the United States, in paper or digital format. It includes maps published in geological survey formal series and open-file series, maps in books, theses and dissertations, maps published by park associations, scientific societies, and other agencies, as well as publications that do not contain a map but instead provide a geological description of an area (for example, a state park). The geologic-names lexicon (GEOLEX) is a search tool for lithologic and geochronologic unit names. It now contains roughly 90% of the geologic names found in the most recent listing of USGS-approved geologic names. Current mapping activities at 1:24,000- and 1:100,000-scale are listed in the Geologic Mapping in Progress Database. Information on how to find topographic maps and list of geology-related links is also available.
[The Journal of Geology, 2007, volume 115, p. 4362] 2007 by The University of Chicago. All rights reserved. 0022-1376/2007/11501-0003$15.00 Pleistocene Brawley and Ocotillo Formations: Evidence for Initial
Housen, Bernie
reserved. 0022-1376/2007/11501-0003$15.00 43 Pleistocene Brawley and Ocotillo Formations: Evidence the Pleistocene tectonic reorganization of the PacificŁNorth American plate boundary in the Salton Trough, and geologic mapping of upper Pliocene to Pleistocene sedimentary rocks in the San Felipe Hills. These deposits
Establishment of an oil and gas database for increased recovery and characterization of oil and gas carbonate reservoir heterogeneity
Mancini, E.A.
The objectives of this project are to augment the National Reservoir Database (TORIS database) and to increase our understanding of geologic heterogeneities that affect the recoveries of oil and gas from carbonate reservoirs in the State of Alabama and to identify those resources that are producible at moderate cost. These objectives will be achieved through detailed geological, engineering, and geostatistical characterization of typical Jurassic Smackover Formation hydrocarbon reservoirs in selected productive fields in the State of Alabama. The results of these studies will be used to develop and test mathematical models for prediction of the effects of reservoir heterogeneities in hydrocarbon production. Work to date has focused on the completion of Subtasks 1, 2, and 3. Subtask 1 included the survey and tabulation of available reservoir engineering and geological data relevant to the Smackover reservoir in southwestern Alabama. Subtask 2 comprises the geological and engineering characterization of Smackover reservoir lithofacies. This has been accomplished through detailed examination and analysis of geophysical well logs, core material, well cuttings, and well-test data from wells penetrating Smackover reservoirs in southwestern Alabama. From these data, reservoir heterogeneities, such as lateral and vertical changes in lithology, porosity, permeability, and diagenetic overprint, have been recognized and used to produce maps, cross sections, graphs, and other graphic representations to aid in interpretation of the geologic parameters that affect these reservoirs. Subtask 3 includes the geologic modeling of reservoir heterogeneities for Smackover reservoirs. This research has been based primarily on the evaluation of key geologic and engineering data from selected Smackover fields. 1 fig.
The Geology of the Terrestrial Planets
NASA Technical Reports Server (NTRS)
Carr, M. H. (editor); Saunders, R. S.; Strom, R. G.; Wilhelms, D. E.
The geologic history of the terrestrial planets is outlined in light of recent exploration and the revolution in geologic thinking. Among the topics considered are planet formation; planetary craters, basins, and general surface characteristics; tectonics; planetary atmospheres; and volcanism.
Geology of the reservoirs from interval I of the Oficina formation, Greater Oficina area, eastern Venezuela Basin
Rivero, C.A.; Scherer, W. [Intevep, S.A., Los Teques (Venezuela)
In order to determine the geologic features of the reservoirs and their areal statistical distribution and geometry, a study was made of a selected interval where the sands present less coalescence and the reservoirs are clearly defined. The study area comprises 1900 km{sup 2} of the Greater Oficina area; core samples, logs and reservoir maps were used. It was found that interval I consists of interbedded sandstones, shales, some siltstone, and occasionally lignites. Based upon lithologic mesoscopic features, eight (8) characteristic lithofacies could be defined. Rocks classified as sub-litharenites, sub-arkoses, arkoses lithic sandstones and graywackes could be inferred as belonging to a fluvio-deltaic system sourced on the Pre-Cambrian Guayana shield. The diagenetic level reached by the sequence corresponds to the intermediate stage, where significant processes of cementation by oxides, carbonates and silica are of equal intensity and magnitude to the lixiviation of feldspars and other detritic particles, giving these rooks good potential reservoir qualities. Descriptive statistical evaluation was performed on 140 reservoirs representing all lithofacies populations in this interval. Based on this analysis reservoirs were statistically grouped in classes which are a function of their geometry, spatial location and type of hydrocarbon content.
Geologic structure generated by large-impact basin formation observed at the South Pole-Aitken basin on the Moon
NASA Astrophysics Data System (ADS)
Ohtake, Makiko; Uemoto, Kisara; Yokota, Yasuhiro; Morota, Tomokatsu; Yamamoto, Satoru; Nakamura, Ryosuke; Haruyama, Junichi; Iwata, Takahiro; Matsunaga, Tsuneo; Ishihara, Yoshiaki
The South Pole-Aitken (SPA) basin is the largest clearly recognized basin on the lunar surface. Determining the composition and structure of the SPA basin interior provides critical constraints on the deep crustal and/or mantle composition of the Moon and improves our understanding of large-basin-forming impact processes. Here we present a new mineralogical map of the SPA basin interior, based on high-spatial-resolution reflectance spectra using the SELENE (Kaguya) multiband imager, which is combined with topographic data in order to interpret the geologic context. The derived mineralogical map suggests extensive distribution of ejected low-Ca pyroxene-dominant mantle material with the presence of purest anorthosite crustal materials surrounding a possible melt pool of 0.26 to 0.33 of the basin diameter near the basin center, which is significantly smaller than that suggested by the crater-scaling law. The absence of clear evidence of lower crustal material is consistent with recent impact simulation results.
Heterogeneous nucleation-controlled particulate formation of recombinant human platelet-activating factor acetylhydrolase in pharmaceutical formulation.
Chi, Eva Y; Weickmann, Joachim; Carpenter, John F; Manning, Mark C; Randolph, Theodore W
Clinical lots of recombinant human platelet-activating factor acetylhydrolase (rhPAF-AH) were prepared in a lyophilized formulation. After reconstitution with sterile water for injection to form an aqueous solution (10 mM sodium citrate, 7.5 w/v% sucrose, and 0.1 w/v% Pluronic-F68, pH 6.5), a few visible, slowly growing particles formed consistently within hours at room temperature. To investigate the mechanism of this phenomenon, immediately after reconstitution, all protein aggregates and exogenous particles were removed by filtration. During 20 days incubation at room temperature, no visible aggregates formed in these filtered samples. In contrast, when nano-sized hydrophilic silica particles were added, they seeded rapid and extensive aggregation of rhPAF-AH. This effect was exacerbated in solutions containing a lower Pluronic-F68 concentration at 0.01%. Aggregation occurred even under conditions where rhPAF-AH adsorption was reversible, and induced no detectable changes to protein secondary and tertiary structures. Decreasing the extent (e.g., adding Pluronic-F68) or affinity (e.g., increasing solution pH) of rhPAF-AH adsorption on nano-sized silica particles was found to be effective at reducing aggregation. Accelerated aggregation was not observed when rhPAF-AH formulation was seeded with aggregated rhPAF-AH. These results show that rhPAF-AH aggregation proceeds through a heterogeneous nucleation-controlled mechanism, where exogenous particles present in solution serve as seeds on which rhPAF-AH adsorb, nucleate, and grow into large aggregates. PMID:15570600
Geology and petrology of the Hormuz dolomite, Infra-Cambrian: Implications for the formation of the salt-cored Halul and Shraouh islands, Offshore, State of Qatar
NASA Astrophysics Data System (ADS)
Nasir, Sobhi; Al-Saad, Hamad; Alsayigh, Abudlrazak; Weidlich, Oliver
Geological investigations of the Halul and the Shraouh islands, offshore Qatar, indicate that most of their calcareous rocks, which display abundant stromatolitic bedding, belong to the Infra-Cambrian Hormuz Series. Mineralogical, petrological, and geochemical analyses show that these calcareous rocks consist dominantly of dolomite and have formed in a reducing depositional environment. Faint laminations and small streaks of organic matter furnish evidence for the involvement of algal mats in their genesis and indicate their formation in an intertidal to supratidal setting. The Halul and Shraouh dolomites experienced extensive recrystallization and sulfatization during the emplacement of the Halul and Shraouh salt domes that form the cores of the islands. During mobilization and ascent of the salt, the dolomite recrystallized, and its Sr initial ratios were abnormally enhanced by the incorporation of 87Sr from a source, which is more radiogenic than the attendant seawater at the time of the dolomite formation near the Proterozoic-Cambrian boundary. Geochemical analysis show that Si, Al, Ti Zr, and % of insoluble residue are highly correlative, suggesting the presence of detrital minerals such as rutile and zircon. A paleosabkha model may well agree with this chemical signature. However, the Infra-Cambrian age of the Hormuz rocks and the presence of stromatolitic layers containing organic materials in the studied rocks, suggest that organogenic dolomitization could be an alternative dolomitization model.
ERIC Educational Resources Information Center
Hoover, Linn
Briefly discusses recent international programs in various areas of geology, including land-use problems, coping with geological hazards, and conserving the environment while searching for energy and mineral resources. (MLH)
ERIC Educational Resources Information Center
Dunn, James R.
Discusses ways that geologic techniques can be used to help evaluate our environment, make economic realities and environmental requirements more compatible, and expand the use of geology in environmental analyses. (MLH)
NSDL National Science Digital Library
Marli Bryant Miller
This site from Marli Bryant Miller, a professor at the University of Oregon, presents images of geological features from around the world. Photographs of glacial features, igneous and metamorphic rocks and processes, and structural geology are featured.
ERIC Educational Resources Information Center
Rapp, George
Describes the rapid expansion of archeological geology, especially in the area of archeological excavations, where geologists use dating techniques and knowledge of geological events to interpret archeological sites. (MLH)
Geologic Reconnaissance of the Antelope-Ashwood Area, North-Central Oregon: With Emphasis on the John Day Formation of Late Oligocene and Early Miocene Age
Peck, Dallas L.
This report briefly describes the geology of an area of about 750 square miles in Jefferson, Wasco, Crook, and Wheeler Counties, Oregon. About 16,000 feet of strata that range in age from pre-Tertiary to Quaternary are exposed. These include the following units: pre-Tertiary slate, graywacke, conglomerate, and meta-andesite; Clarno Formation of Eocene age - lava flows, volcanic breccia, tuff, and tuffaceous mudstone, chiefly of andesitic composition; John Day Formation of late Oligocene and early Miocene age - pyroclastic rocks, flows, and domes, chiefly of rhyolitic composition; Columbia River Basalt of middle Miocene age - thick, columnar jointed flows of very fine grained dense dark-gray basalt; Dalles Formation of Pliocene age - bedded tuffaceous sandstone, siltstone, and conglomerate; basalt of Pliocene or Pleistocene age - lava flows of porous-textured olivine basalt; and Quaternary loess, landslide debris, and alluvium. Unconformities separate pre-Tertiary rocks and Clarno Formation, Clarno and John Day Formations, John Day Formation and Columbia River Basalt, and Columbia River Basalt and Dalles Formation. The John Day Formation, the only unit studied in detail, consists of about 4,000 feet of tuff, lapilli tuff, strongly to weakly welded rhyolite ash flows, and less abundant trachyandesite flows and rhyolite flows and domes. The formation was divided into nine mappable members in part of the area, primarily on the basis of distinctive ledge-forming welded ash-flow sheets. Most of the sheets are composed of stony rhyolite containing abundant lithophysae and sparse phenocrysts. One sheet contains 10 to 20 percent phenocrysts, mostly cryptoperthitic soda sanidine, but including less abundant quartz, myrmekitic intergrowths of quartz and sanidine, and oligoclase. The rhyolitic ash flows and lava flows were extruded from nearby vents, in contrast to some of the interbedded air-fall tuff and lapilli tuff of dacitic and andesitic composition that may have been derived from vents in an ancestral Cascade Range. The John Day is dated on the basis of a late Oligocene flora near the base of the formation and early Miocene faunas near the top of the formation. The middle Miocene and older rocks in the Antelope-Ashwood area are broadly folded and broken along northeast-trending faults. Over much of the area the rocks dip gently eastward from the crest of a major fold and are broken along a series of steeply dipping antithetic strike faults. Pliocene and Quaternary strata appear to be undeformed. At the Priday agate deposit, chalcedony-filled spherulites (thunder-eggs) occur in the lower part of a weakly welded rhyolitic ash flow. The so-called thunder-eggs are small spheroidal bodies, about 3 inches in average diameter; each consists of a chalcedonic core surrounded by a shell of welded tuff that is altered to radially oriented fibers of cristobalite and alkalic feldspar.
Evaluation of Impacts of Permeability and Porosity of Storage Formations on Leakage Risk of Deep Groundwater and Carbon Dioxide Due to Geologic Carbon Dioxide Storage
NASA Astrophysics Data System (ADS)
Lee, S.; Park, J. Y.; Park, S. U.; Kim, J. M.; Kihm, J. H.
A series of analysis modeling was performed using a behavior prediction model and a leakage risk analysis model to evaluate quantitatively impacts of hydrogeologic properties (intrinsic permeability and porosity) of storage formations (reservoir rocks) on leakage risk of deep groundwater (brine) and carbon dioxide (CO2) due to geologic CO2 storage. In this study, an abandoned well and a fault are considered as leakage pathways for deep groundwater and CO2 leakage from a storage formation into an overlying near-surface aquifer. A series of prediction modeling of behavior of deep groundwater and CO2 in the storage formation was performed first using a behavior prediction model TOUGH2 (Pruess et al., 1999, 2012) to obtain spatial and temporal distributions of the pressure, temperature, and saturation of deep groundwater and CO2 as well as the mass fraction (solubility) of CO2 in deep groundwater along the upper boundary of the storage formation beneath the overlying cap rock. These spatial and temporal distributions are used as input data in the next leakage risk analysis modeling. A series of analysis modeling of leakage risk of deep groundwater and CO2 through either the abandoned well or the fault was then performed using a leakage risk analysis model CO2-LEAK (Kim, 2012). The analysis modeling results show that CO2 injection can cause deep groundwater (brine) and CO2 (both free fluid and aqueous phases) leakage into the overlying near-surface aquifer through either the abandoned well or the fault. In that case, brine leaks first, aqueous phase of CO2 then leaks, and free fluid phase of CO2 leaks finally, whereas their leakage rates and amounts through the fault is much greater than those through the abandoned well. The analysis modeling results also reveal that the leakage rate and amount of deep groundwater are almost independent of permeability and porosity of the storage formation. However, the leakage rate and amount of CO2 are dependent on and inversely proportional to them. In addition, the leakage rate and amount of CO2 are more sensitive to permeability than porosity of the storage formation. This work was supported by the Geo-Advanced Innovative Action (GAIA) Program funded by the Korea Environmental Industry and Technology Institute (KEITI), Ministry of Environment, Republic of Korea.
NSDL National Science Digital Library
Created by the University of Nebraska-Lincoln, this site describes the basics of structural geology with text and images. The page includes the discussion of stress, strain, strike and dip, faults, folds, mountain building, erosion, economic geology, and environmental geology. This is a nice introduction to the basic topics in geology. Images from the field help to enhance the topics on the site. Instructors can use this resource to help create or simply enhance their curriculum.
The relationship of dynamical heterogeneity to the Adam-Gibbs and random first-order transition theories of glass formation
Starr, Francis W.; Douglas, Jack F.; Sastry, Srikanth
We carefully examine common measures of dynamical heterogeneity for a model polymer melt and test how these scales compare with those hypothesized by the Adam and Gibbs (AG) and random first-order transition (RFOT) theories of relaxation in glass-forming liquids. To this end, we first analyze clusters of highly mobile particles, the string-like collective motion of these mobile particles, and clusters of relative low mobility. We show that the time scale of the high-mobility clusters and strings is associated with a diffusive time scale, while the low-mobility particles' time scale relates to a structural relaxation time. The difference of the characteristic times for the high- and low-mobility particles naturally explains the well-known decoupling of diffusion and structural relaxation time scales. Despite the inherent difference of dynamics between high- and low-mobility particles, we find a high degree of similarity in the geometrical structure of these particle clusters. In particular, we show that the fractal dimensions of these clusters are consistent with those of swollen branched polymers or branched polymers with screened excluded-volume interactions, corresponding to lattice animals and percolation clusters, respectively. In contrast, the fractal dimension of the strings crosses over from that of self-avoiding walks for small strings, to simple random walks for longer, more strongly interacting, strings, corresponding to flexible polymers with screened excluded-volume interactions. We examine the appropriateness of identifying the size scales of either mobile particle clusters or strings with the size of cooperatively rearranging regions (CRR) in the AG and RFOT theories. We find that the string size appears to be the most consistent measure of CRR for both the AG and RFOT models. Identifying strings or clusters with the ōmosaicö length of the RFOT model relaxes the conventional assumption that the ōentropic dropletsö are compact. We also confirm the validity of the entropy formulation of the AG theory, constraining the exponent values of the RFOT theory. This constraint, together with the analysis of size scales, enables us to estimate the characteristic exponents of RFOT. PMID:23556792
NSDL National Science Digital Library
"Why do engineers need to know about geologic time?" That question is answered in this resource from the University of Saskatchewan's Department of Civil and Geological Engineering. Provided here is a discussion of the concepts of geological time; relative dating methods, such as correlation; and absolute dating methods, such as radiometric methods. Diagrams and charts are included to demonstrate these complex concepts.
NSDL National Science Digital Library
Jagoutz, Oliver
If you are having difficulty remembering the details of the Earth's geological structure or the nature of major minerals and rock types, you can consult this excellent introductory course offered as part of MIT's OpenCourseWare initiative. The materials are drawn from Professors Perron and Jagoutz's 2011 "Introduction to Geology" course, and they include a number of lecture notes, available for download in PDF file format. The course is designed for undergraduates, though anyone can benefit from examining the materials. Visitors can make their way through lecture notes that cover metamorphic rocks, rock deformation, earthquakes, and the formation of continents.
Uncertainty quantification for flow in highly heterogeneous porous media
Tartakovsky, D. M. (Daniel M.); Xiu, D. (Dongbin)
Natural porous media are highly heterogeneous and characterized by parameters that are often uncertain due to the lack of sufficient data. This uncertainty (randomness) occurs on a multiplicity of scales. We focus on geologic formations with the two dominant scales of uncertainty: a large-scale uncertainty in the spatial arrangement of geologic facies and a small-scale uncertainty in the parameters within each facies. We propose an approach that combines random domain decompositions (RDD) and polynomial chaos expansions (PCE) to account for the large- and small-scales of uncertainty, respectively. We present a general framework and use a one-dimensional flow example to demonstrate that our combined approach provides robust, non-perturbative approximations for the statistics of the system states.
Heterogeneous distribution of plankton within the mixed layer and its implications for bloom formation in tropical seas.
Calbet, Albert; Agersted, Mette Dalgaard; Kaartvedt, Stein; M°hl, Malene; M°ller, Eva Friis; Enghoff-Poulsen, S°ren; Paulsen, Maria Lund; Solberg, Ingrid; Tang, Kam W; T÷nnesson, Kajsa; Raitsos, Dionysios E; Nielsen, Torkel Gissel
Intensive sampling at the coastal waters of the central Red Sea during a period of thermal stratification, prior to the main seasonal bloom during winter, showed that vertical patches of prokaryotes and microplankton developed and persisted for several days within the apparently density uniform upper layer. These vertical structures were most likely the result of in situ growth and mortality (e.g., grazing) rather than physical or behavioural aggregation. Simulating a mixing event by adding nutrient-rich deep water abruptly triggered dense phytoplankton blooms in the nutrient-poor environment of the upper layer. These findings suggest that vertical structures within the mixed layer provide critical seeding stocks that can rapidly exploit nutrient influx during mixing, leading to winter bloom formation. PMID:26062783
Coalescence of clusters of catalysts for the growth of carbon nanotubes during their formation under homogeneous and heterogeneous conditions
NASA Astrophysics Data System (ADS)
Bulyarskii, S. V.; Basaev, A. S.
The formation of clusters of catalysts for the growth of carbon nanotubes has been investigated experimentally and theoretically. An expression for the size distribution of monomolecular and globular clusters formed upon coalescence has been obtained. It has been shown that the maximum of the distribution is determined by the effective surface tension coefficient. The effective surface tension coefficients for clusters formed in the gas phase and on the substrate have been estimated. It has been found that the effective surface tension coefficient for a substrate based on silicon oxide is less than that of the clusters formed on silicon and in the gas phase. In the case of a globular cluster, the effective surface tension coefficient tends to the characteristic value for the bulk material.
Heterogeneous distribution of plankton within the mixed layer and its implications for bloom formation in tropical seas
Calbet, Albert; Agersted, Mette Dalgaard; Kaartvedt, Stein; M°hl, Malene; M°ller, Eva Friis; Enghoff-Poulsen, S°ren; Paulsen, Maria Lund; Solberg, Ingrid; Tang, Kam W.; T÷nnesson, Kajsa; Raitsos, Dionysios E.; Nielsen, Torkel Gissel
Intensive sampling at the coastal waters of the central Red Sea during a period of thermal stratification, prior to the main seasonal bloom during winter, showed that vertical patches of prokaryotes and microplankton developed and persisted for several days within the apparently density uniform upper layer. These vertical structures were most likely the result of in situ growth and mortality (e.g., grazing) rather than physical or behavioural aggregation. Simulating a mixing event by adding nutrient-rich deep water abruptly triggered dense phytoplankton blooms in the nutrient-poor environment of the upper layer. These findings suggest that vertical structures within the mixed layer provide critical seeding stocks that can rapidly exploit nutrient influx during mixing, leading to winter bloom formation. PMID:26062783
Heterogeneity in resistance to food-related stresses and biofilm formation ability among verocytotoxigenic Escherichia coli strains.
Alvarez-Ord¾±ez, A; Alvseike, O; Omer, M K; Heir, E; Axelsson, L; Holck, A; Prieto, M
This study assessed the resistance of ten verocytotoxigenic Escherichia coli (VTEC) isolates of commonly encountered serogroups/-types and two non-pathogenic E. coli strains to various food-related stresses (acid, alkaline, heat and high hydrostatic pressure treatments) and their biofilm formation ability. In addition, the global changes in the cellular composition in response to the exposure to these adverse environments were monitored by Fourier Transform Infrared (FT-IR) spectroscopy for two of the strains. Large inter-strain variations in stress resistance were observed. The most tolerant strains belonged to serogroup O157 which included both the O157:H7 type strain EDL933 and a representative isolate of the sorbitol fermenting O157:H- VTEC clone (strain MF3582). Strain C-600, a non-pathogenic laboratory strain, was sensitive to multiple stresses. Although wide variation in biofilm-forming ability was observed among VTEC isolates, no consistent relationships between biofilm-forming ability and capacity to withstand stress exposures were found. Analysis of the allelic status of the rpoS gene, involved in the general stress response of stationary-phase cells, allowed detection of loss-of-function mutations for two strains, E218/02 and MF2411, both of them showing as common features a high sensitivity to alkaline and heat treatments and a poor ability to form mature biofilms. Evidences found in this study confirm rpoS as a highly mutable gene in nature, and suggest its relevance not only for the mount of an active stress response but also for the establishment of mature biofilm communities. Our findings contribute to increase the knowledge on the resistance of VTEC to environmental stresses commonly encountered in the food chain, which can lead to improved strategies for preventing VTEC infections. PMID:23337122
Sudbury project (University of Muenster-Ontario Geological Survey): Origin of the polymict, allochthonous breccias of the Onaping Formation
NASA Technical Reports Server (NTRS)
Avermann, M. E.
The Sudbury structure has been interpreted as a deeply eroded remnant of a peak-ring basin. The polymict, allochthonous breccias of the Onaping Formation (OF) occur in the central part of the Sudbury structure, which is surrounded by the 1.85-Ga-old 'Sudbury Igneous Complex' (SIC). From bottom to top the OF can be divided into Basal, Gray, Green, and lower and upper Black members. The breccias were mapped in detail in the east range of the structure. The SIC and the lower part of the OF (Basal Member) are interpreted as the impact melt system. The overlying Gray Member is a breccia unit with a clastic matrix and has a sharp contact to the Basal Member. The Green Member is considered as a continuous uniform breccia layer on top of the Gray Member and comprises the former 'chlorite shard horizon'. The uppermost unit of the OF (Black Member) can be subdivided into a lower and an upper Black Member unit. The lower part (100-150 m thick) still shows petrographic features of suevitic breccias, small fragments of basement rocks, melt particles, chloritized particles, and breccia fragments in a dark, clastic matrix.
NASA Technical Reports Server (NTRS)
Greeley, R. (editor); Schultz, P. H. (editor)
Primary topics in lunar geology range from the evolution of the solar system to lunar photointerpretation, impact crater formation, and sampling to analyses on various Apollo lunar landing site geomorphologies.
Dolomitization and neomorphism of Mississippian (Visean) upper debolt formation, Blueberry field, northeastern British Columbia: Geologic, petrologic, and chemical evidence
Durocher, S.; Al-Aasm, I.S. [Univ. of Windsor, Ontario (Canada)
Petrographic, chemical, and isotopic studies of the Mississippian (Visean) upper Debolt Formation in the Blueberry field, British Columbia, Canada, reveal that dolomitization was the result of several diagenetic events and that neomorphic alteration of these dolomites significantly modified their original chemical signatures. These studies also demonstrate how tectonics play an important role in controlling and modifying reservoir dolomites in the area. Petrographic investigations have documented two early dolomite phases, (1) early matrix dolomite and (2) pervasive dolomite, and two later generations, (3) coarse cement and (4) pseudomorphic replacement of crinoids. Early matrix dolomite occurs as small (average 25 {mu}m) subhedral to euhedral crystals that replace the matrix of carbonate mudstones, wackestones, and packstones. Petrographic evidence suggests that early matrix dolomite had a relatively early, precompaction origin, possibly from marine fluids. However, geochemical evidence indicates that later fluids have altered their original geochemical signatures. Pervasive dolomite, which forms the reservoir intercrystalline porosity, occurs with planar-s and planar-e textures. Planar-s crystals typically have a dirty appearance and exhibit homogeneous dull brown/red cathodoluminescence colors. Planar-e crystals may appear with a cloudy core and a clear rim, and under cathodoluminescence display an irregular dull brown/red core and a thin, bright red rim. Due to the spatial distribution pattern of pervasive dolomite with respect to the overlying unconformity surface, its paleogeographic distribution and close temporal relationship with meteoric diagenetic events, pervasive dolomite formed from a mixture of seawater and meteoric fluids. However, alteration of their primary chemistry by later fluids is indicated by their depleted {delta}{sup 18}O values and radiogenic {sup 87}Sr/{sup 86}Sr ratios.
Novel Nitro-PAH Formation from Heterogeneous Reactions of PAHs with NO2, NO3/N2O5, and OH Radicals: Prediction, Laboratory Studies and Mutagenicity
The heterogeneous reactions of benzo[a]pyrene-d12 (BaP-d12), benzo[k]fluoranthene-d12 (BkF-d12), benzo[ghi]perylene-d12 (BghiP-d12), dibenzo[a,i]pyrene-d14 (DaiP-d14), and dibenzo[a,l]pyrene (DalP) with NO2, NO3/N2O5, and OH radicals were investigated at room temperature and atmospheric pressure in an indoor Teflon chamber and novel mono NO2-DaiP, and mono NO2-DalP products were identified. Quartz fiber filters (QFF) were used as a reaction surface and the filter extracts were analyzed by GC/MS for nitrated-PAHs (NPAHs) and tested in the Salmonella mutagenicity assay, using Salmonella typhimurium strain TA98 (with and without metabolic activation). In parallel to the laboratory experiments, a theoretical study was conducted to rationalize the formation of NPAH isomers based on the thermodynamic stability of OH-PAH intermediates, formed from OH-radical-initiated reactions. NO2 and NO3/N2O5 were effective oxidizing agents in transforming PAHs to NPAHs, with BaP-d12 being the most readily nitrated. Reaction of BaP-d12, BkF-d12 and BghiP-d12 with NO2 and NO3/N2O5 resulted in the formation of more than one mono-nitro isomer product, while the reaction of DaiP-d14 and DalP resulted in the formation of only one mono-nitro isomer product. The direct-acting mutagenicity increased the most after NO3/N2O5 exposure, particularly for BkF-d12 in which di-NO2-BkF-d10 isomers were measured. The deuterium isotope effect study suggested that substitution of deuterium for hydrogen lowered both the direct and indirect acting mutagenicity of NPAHs and may result in an underestimation of the mutagencity of the novel NPAHs identified in this study. PMID:24350894
NSDL National Science Digital Library
Utah Geological Survey's Web site, Utah Geology, offers a variety of interesting geological information about the state. Good descriptions, illustrations, and photographs can be accessed on earthquakes and hazards, dinosaurs and fossils, rocks and minerals, oil and energy, and more. For example, the Rocks and Minerals page contains everything from how to stake a mining claim to downloadable summaries of mineral activity in the state. There is quite a bit of information within the site, and anyone interested in geology will find themselves exploring these pages for quite a while.
Geologic Controls Influencing CO2 Loss from a Leaking Well
NASA Astrophysics Data System (ADS)
Klise, K. A.; Martinez, M. J.; McKenna, S. A.; Hopkins, P. L.
Injection of CO2 into formations containing brine is proposed as a long-term sequestration solution. A significant obstacle to sequestration performance is the presence of existing wells providing a transport pathway out of the sequestration formation. To understand how heterogeneity impacts the leakage rate, we employ two dimensional models of the CO2 injection process into a sandstone aquifer with shale inclusions to examine the parameters controlling release through an existing well. This scenario is modeled as a constant-rate injection of super-critical CO2 into the existing formation where buoyancy effects, relative permeabilities, and capillary pressures are employed. Three geologic controls are considered: stratigraphic dip angle, shale inclusion size and shale fraction. In this study, we examine the impact of heterogeneity on the amount and timing of CO2 released through a leaky well. Sensitivity analysis is performed to classify how various geologic controls influence CO2 loss. A ōDesign of Experimentsö approach is used to identify the most important parameters and combinations of parameters to control CO2 migration while making efficient use of a limited number of computations. Results are used to construct a low-dimensional description of the transport scenario. The goal of this exploration is to develop a small set of parametric descriptors that can be generalized to similar scenarios. Results of this work will allow for estimation of the amount of CO2 that will be lost for a given scenario prior to commencing injection. Additionally, two-dimensional and three-dimensional simulations are compared to quantify the influence that surrounding geologic media has on the CO2 leakage rate. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company for the U.S. Department of EnergyÆs National Nuclear Security Administration under contract DE-AC04-94AL85000.
Stochastic Representation of Sedimentary Geology
NASA Astrophysics Data System (ADS)
Elmouttie, M. K.; Krõhenb³hl, G.; Poropat, G. V.; Kelso, I.
Discrete fracture network representations of discontinuities in rock masses have been shown to be useful in capturing heterogeneity in rock mass properties. Providing computational efficiency in the resulting simulations and analyses is attained, these fracture representations can be combined with structural modelling and sampling algorithms. Multiple fracture network realisations can be generated and the resulting rock mass properties interrogated. Statistical analyses based on fracture connectivity, block size distribution and slope stability can be performed and provide results defined in terms of confidence intervals. For sedimentary geology consisting of dense bedding, equivalent medium continuum methods have traditionally been used in preference to discrete fracture representations due to the large numbers of structures involved and resulting computational complexity. In this paper, it is shown that stochastic representation of these layers can be employed. An analytical solution to accommodate bedding given an assumed block size distribution has been derived. Using this formulation, polyhedral modelling has been used to investigate the influence of bedding on block formation and block size distributions using field data. It is shown that the analysis is both computationally efficient and can capture truncation of size distribution by such layers without numerical methods.
North Cascades Geology: Geologic Time
NSDL National Science Digital Library
This article describes the period of geologic time spanned by the rocks of the North Cascades area of Washington. Users can access a simplified geologic time scale that provides links to geologic events in the North Cascades region. These include the deposition of various terranes, periods of intrusion and metamorphism, the beginning of the Cascade volcanic arc, and periods of major glaciation. Links to related materials are also provided.
NASA Astrophysics Data System (ADS)
McKeown, M. H.; Beason, S. C.
The geological gyrocompass is an accurate, portable instrument useful for geologic mapping and surveying which employs an aircraft gyrocompass, strike reference bars, a pair of sights and levelling devices for horizontally levelling the instrument. A clinometer graduated in degrees indicates the dip of the surface being measured.
NSDL National Science Digital Library
The National Park Service maintains the Yosemite National Park Web site and the corresponding Geology page. This Web site gives an overview of the geologic history of the site, tells how the Sierra Nevada range formed, explains the basics of granitic rock, shows how glaciers carved out the canyons, and much more.[JAB
A Mechanism for the Formation and Evolution of Tharsis as a Consequence of Mantle Overturn: Large Scale Lateral Heterogeneity in a Stably Stratified Mantle
E. M. Parmentier; S. E. Zaranek; L. T. Elkins-Tanton
Tharsis is considered a consequence of melting of a large scale mantle heterogeneity following mantle overturn after fractional magma ocean solidification. Long-lived volcanism does not require a long term heat flux from the core or magnetic field.
Geology Programs and Disciplinary Accreditation
NSDL National Science Digital Library
Robert Corbett
This report raises the question of whether accreditation may be coming to the geology discipline, and attempts to quantify the positions on accreditation of academic department heads/chairs. The study makes a distinction between institutional and specialized (or disciplinary) accreditation and explores attitudes toward both types. Results of the analysis are presented with a discussion of two methods of data interpretation, a multivariate analysis technique and the Chi square test for heterogeneity or independence. The report concludes that there is currently insufficient support for establishing disciplinary accreditation in geology.
NSDL National Science Digital Library
William L. Newman
The Earth is very old -- 4.5 billion years or more -- according to recent estimates. This vast span of time, called geologic time by earth scientists, is difficult to comprehend in the familiar time units of months and years, or even centuries. How then do scientists reckon geologic time, and why do they believe the Earth is so old? A great part of the secret of the Earth's age is locked up in its rocks, and our centuries-old search for the key led to the beginning and nourished the growth of geologic science.
Newman, William L.
The Earth is very old 4 1/2 billion years or more according to recent estimates. This vast span of time, called geologic time by earth scientists, is difficult to comprehend in the familiar time units of months and years, or even centuries. How then do scientists reckon geologic time, and why do they believe the Earth is so old? A great part of the secret of the Earth's age is locked up in its rocks, and our centuries-old search for the key led to the beginning and nourished the growth of geologic science.
NSDL National Science Digital Library
Philip Medina
This unit introduces younger students to the concept of relative versus absolute time and how geologists determine the age of geologic events and features. Topics include the laws that determine relative age (superposition, cross-cutting relationships, included fragments, and others), and how to re-construct the geologic history of an area using these relationships. There is also information on geologic correlation and the use of index fossils to determine relative age. The section on absolute time discusses some ways of measurement (tree rings, radioactive dating) and introduces the concepts of natural selection and mass extinctions. A vocabulary and downloadable, printable student worksheets are provided.
NSDL National Science Digital Library
This set of lessons provides teachers with ideas on how to turn their schoolyards into a rich geologic experience that students will find familiar, easily accessible, and personally relevant. The three lesson plans feature materials on mapping, rock descriptions and geologic interpretations, ages of rocks, and dinosaur tracks. Lesson 1, "Map Your Schoolyard," teaches students what maps are, what they are used for, and some symbols used on maps (north arrow, scale bar, legend, etc.). Lesson 2, "Rock Stories," illustrates how to make geologic observations and what important properties of rocks to look for. Lesson 3, "GeoSleuth Schoolyard," teaches students that geology is a lot like detective work, in which geologists infer the sequence and timing of events by collecting evidence and making observations. Relevant California state science standards are also listed.
Scale Length of Mantle Heterogeneities: Helium Diffusion Constraints
S. Hart; M. Kurz; Z. Wang
While Earth's mantle is unequivocally heterogeneous, the size, formation and distribution of these geochemical heterogeneities remain enigmatic. Following the veined mantle proposals of Hanson (1977) and Wood (1979), various postulates of mesoscale lithologic heterogeneities (veins, pods, layers, plums) have been advanced. However, the issue remains contentious, and no smoking gun has survived scrutiny. Do the heterogeneities reflect large scale (tens
Borehole geological assessment
NASA Technical Reports Server (NTRS)
Spuck, W. H., III (inventor)
A method and apparatus are discussed for performing geological assessments of a formation located along a borehole, and a boring tool that bores a pair of holes into the walls of the borehole and into the surrounding strata along with a pair of probes which are installed in the holes. One of the probes applies an input such as a current or pressured fluid, and the other probe senses a corresponding input which it receives from the strata.
NSDL National Science Digital Library
Visitors to this site can learn about the theory of plate tectonics, the history of its development, and the mechanisms that drive the formation, movement, and destruction of continents and tectonic plates. A selection of animations depicts the movements of crustal plates and continents through time. Each animation is accompanied by an interactive time scale that provides links to descriptions of the geology and paleontology of the selected era or period.
Digitizing rocks standardizing the geological description process using workstations
Saunders, M.R. (EXLOG (Services), Windsor, Berkshire (United Kingdom)); Shields, J.A. (EXLOG North Sea, Aberdeen (United Kingdom)); Taylor, M.R. (EXLOG, Inc., Houston, TX (United States))
The preservation of geological knowledge in a standardized digital form presents a challenge. Data sources, inherently fuzzy, range in scale from the macroscopic (e.g., outcrop) through the mesoscopic (e.g., hand-specimen) core and sidewall core, to the microscopic (e.g., drill cuttings, thin sections, and microfossils). Each scale change results in increased heterogeneity and potentially contradictory data and the providers of such data may vary in experience level. To address these issues with respect to cores and drill cuttings, a geological description workstation has been developed and is undergoing field trials. Over 1000 carefully defined geological attributes are currently available within a depth-indexed, relational database. Attributes are stored in digital form, allowing multiple users to select familiar usage (e.g., diabase vs. dolerite). Data can be entered in one language and retrieved in other languages. The database structure allow groupings of similar elements (e.g., rhyolites in acidic, igneous or volcanics subgroups or the igneous rock group) permitting different uses to analyze details appropriate to the scale of the usage. Data entry uses a graphical user interface, allowing the geologist to make quick, logical selections in a standardized or custom-built format with extensive menus, on-screen graphics and help screens available. Description ranges are permissible. Entries for lithology, petrology, structures (sedimentary, organic and deformational), reservoir characteristics (porosity and hydrocarbon shows), and macrofossils are available. Sampling points for thin sections, core analysis, geochemistry, or micropaleontology studies are also recorded. Using digital data storage, geological logs using graphical, alphanumeric and symbolic depictions are possible. Data can be integrated with drilling and mud gas data, MWD and wireline data and off well-site analyses to produced composite formation evaluation logs and interpretational crossplots.
NASA Astrophysics Data System (ADS)
Weber, John; Frankel, Kurt L.
Structural geology and continental tectonics were ushered in to the modern quantitative age of geosciences with the arrival of the global plate tectonics paradigm (circa 1968), derived using new data from the oceans' depths, and John Ramsay's 1967 seminal work, Folding and Fracturing of Rocks. Fossen is to be applauded for crafting a unique, high-caliber, and accessible undergraduate textbook on structural geology that faithfully reflects this advance and the subsequent evolution of the discipline. This well-written text draws on Fossen's wealth of professional experience, including his broad and diverse academic research and experience in the petroleum industry. This book is beautifully illustrated, with excellent original color diagrams and with impressive color field photographs that are all keyed to locations and placed into geologic context.
Geological map of the future: digital, interactive, and 3D
NASA Astrophysics Data System (ADS)
Thorleifson, H.
Geological survey agencies are developing methods for government geological mapping in the post-paper map era. Surficial and bedrock maps are being digitized and reconciled, while multiple generations of legends are being made accessible in a categorized format. Regional 3D geological models that integrate soils and geology, surficial and bedrock geology, as well as onshore and offshore are increasingly in demand as the information, technology, and protocols to build them progress. Applications such as regional groundwater modelling require digitizing, reconciliation, and assembly of a digital elevation model, bathymetry, offshore geology, soils, surficial geology, public domain drillhole and geophysical data, bedrock maps, and existing stratigraphic models typically expressed as structure contours. New stratigraphic modelling, particularly required for surficial unconsolidated deposits in many regions, requires information from cored holes logged by geologists as well as geophysical surveys. These high-quality results are extrapolated laterally using drill hole data, commonly large quantities of water well data of varying resolution and reliability. Much effort is required to adequately georeference the drillhole data, and to parse large numbers of unique lithological descriptions. Stratigraphic modelling methods ideally use all data and an approach that permits judgement in the acceptance or rejection of data, while interpolation and extrapolation are guided by genetic insights. Models are best captured as a grid of predicted stratigraphy profiles that convey expert opinion on interpolation and extrapolation from the data points. Reconciliation of mapping with that of neighbouring jurisdictions is a key step, as is balancing subjective definition of strata with more objective geostatistical approaches to characterizing the heterogeneous physical properties of the strata. Progress is readily achievable in undeformed strata, while deformed strata present far greater challenges. Increasingly, databases of observations and measurements are being retained alongside the interpreted model, and models are being assigned varying confidence levels such that the result is seen not as an end but a means for prioritizing new mapping. Current activity is broadening our reliance not only from paper maps to digital models, but also from plan view maps, to drillhole databases, to 3D models, to dynamic models such as groundwater flow models. Pressing user requirements demand that geological survey work rapidly advance along this progression.
Upper Cenozoic Geologic Map, Yellowstone Plateau Volcanic Field
NSDL National Science Digital Library
Christiansen Robert
This geologic map shows Tertiary and Quaternary rock formations, volcanic and surficial deposits, faults, contacts, and other geologic features in Yellowstone National Park. The map is freely downloadable as a PDF file.
Testing the Injectivity of CO2 in a Sub-surface Heterogeneous Reservoir
NASA Astrophysics Data System (ADS)
Sundal, A.; Nystuen, J.; Dypvik, H.; Aagaard, P.
This case study on subsurface reservoir characterization, considers the effect of geological heterogeneities on the storage capacity and injectivity of the Johansen Formation, which is a deep, saline aquifer underlying the Troll Gas Field off the Norwegian coast. The Johansen Formation has been interpreted as a sandy, prograding unit, deposited in a shallow marine environment during Early Jurassic time, and is overlain by a shaly unit; the Amundsen Formation. It appears as a wedge shaped sandstone body, up to 140m thick, with an areal extent in the order of 10 000 km2. The Johansen Formation is currently being considered for large scale CO2 storage from two gas power plants situated on the west coast of Norway, both of which will operate with full scale CO2 handling, as proposed by Norwegian authorities. The storage capacity needed is in the order of 3 Mt CO2/year. With access to a new 3D seismic survey (Gassnova, 2010), and based on existing well log data from 25 penetrating wells, we have studied large scale geometries and intra-formational features, and built a geo-conceptual model of the Johansen Formation. The reservoir is heterogeneous, with distinct permeability zonation within clinothems separated by less permeable layers. In order to obtain better understanding of crucial reservoir parameters and supplement limited data, comparison of data from easily accessible analogue rock units is useful. For this purpose the unit should be well exposed and thoroughly documented, such as the Panther Tongue Member (Star Point Formation, Mesa Verde Group) in Book Cliffs, from which we have collected some comparable permeability estimates for the model. On a micro scale, mineralogy, grain size/shape and pore geometry constitue major controls on reservoir porosity and permeability. Direct geological information is at this point in time limited to a few meters of core, from which detailed mineralogical information has been derived (optical microscopy, SEM, XRD), and some additional data from side wall cores and cuttings. From this we evaluate facies dependence related to observed diagenetic features and compositional variations due to burial depth (2-4km), mainly considering chlorite coatings (preserving porosity) and cementation (calcite and quartz). Using Schlumberger soft-wares; Petrel (reservoir) and Eclipse (fluid flow), we are testing injection scenarios (one point, several points, bleeding wells) in several intra-formational geological settings. These results will be evaluated relative to the distribution of facies and heterogeneities in the reservoir, considering multiphase flow given the local pressure regime.
Geology and petrology of the Hormuz dolomite, InfraCambrian: Implications for the formation of the salt-cored Halul and Shraouh islands, Offshore, State of Qatar
Sobhi Nasir; Hamad Al-Saad; Abudlrazak Alsayigh; Oliver Weidlich
Geological investigations of the Halul and the Shraouh islands, offshore Qatar, indicate that most of their calcareous rocks, which display abundant stromatolitic bedding, belong to the Infra-Cambrian Hormuz Series. Mineralogical, petrological, and geochemical analyses show that these calcareous rocks consist dominantly of dolomite and have formed in a reducing depositional environment. Faint laminations and small streaks of organic matter furnish
Geologic and hydrologic controls critical to coalbed methane producibility and resource assessment: Williams Fork Formation, Piceance Basin, Northwest Colorado. Topical report, December 1, 1993-November 30, 1995
Tyler, R.; Scott, A.R.; Kaiser, W.R.; Nance, H.S.; McMurry, R.G.
The objectives of this report are: To further evaluate the interplay of geologic and hydrologic controls on coalbed methane production and resource assessment; to refine and validate our basin-scale coalbed methane producibility model; and to analyze the economics of coalbed methane exploration and development in the Piceance Basin.
Geological processes and evolution
Head, J.W.; Greeley, R.; Golombek, M.P.; Hartmann, W.K.; Hauber, E.; Jaumann, R.; Masson, P.; Neukum, G.; Nyquist, L.E.; Carr, M.H.
Geological mapping and establishment of stratigraphic relationships provides an overview of geological processes operating on Mars and how they have varied in time and space. Impact craters and basins shaped the crust in earliest history and as their importance declined, evidence of extensive regional volcanism emerged during the Late Noachian. Regional volcanism characterized the Early Hesperian and subsequent to that time, volcanism was largely centered at Tharsis and Elysium, continuing until the recent geological past. The Tharsis region appears to have been largely constructed by the Late Noachian, and represents a series of tectonic and volcanic centers. Globally distributed structural features representing contraction characterize the middle Hesperian. Water-related processes involve the formation of valley networks in the Late Noachian and into the Hesperian, an ice sheet at the south pole in the middle Hesperian, and outflow channels and possible standing bodies of water in the northern lowlands in the Late Hesperian and into the Amazonian. A significant part of the present water budget occurs in the present geologically young polar layered terrains. In order to establish more firmly rates of processes, we stress the need to improve the calibration of the absolute timescale, which today is based on crater count systems with substantial uncertainties, along with a sampling of rocks of unknown provenance. Sample return from carefully chosen stratigraphic units could calibrate the existing timescale and vastly improve our knowledge of Martian evolution.
NSDL National Science Digital Library
Timothy Heaton
This site contains 24 questions on the topic of geologic time, which covers dating techniques and unconformities. This is part of the Principles of Earth Science course at the University of South Dakota. Users submit their answers and are provided immediate feedback.
NSDL National Science Digital Library
Humans use soil for their daily needs but do not sufficiently take account of its slow formation and fast loss. Discover the amazing geology of soil formation and the basic rock and soil types.Although soil seems the end product from weathering rocks, it is merely a stage in the gigantic cycle of mineral recycling by the movement of tectonic plates.
Integrating geology and perforating
Araujo, P.F. de [Petrobras, Rio de Janeiro (Brazil); Souza Padilha, S.T.C. de [Schlumberger Wireline and Testing, Rio de Janeiro (Brazil)
Perforating is a very common well completion operation. Usually, it is considered to be as simple as making holes in casing. Actually, perforating is one of the most critical tasks for establishing a path from reservoir rock to borehole form which hydrocarbons can flow to surface. The objective of this article is to relate perforating technology with geological aspects and completion type to determine the best shooting equipment (gun type, charge and differential pressure) to perform the most efficient perforating job. Several subjects related to formation geology are taken into account for a shooting job, such as: compressive strength, reservoir pressure and thickness, lithology type, porosity and permeability, ratio between horizontal and vertical permeabilities, and fluid type. Gun geometry used in the oil industry incorporates several parameters, including shot density, hole entrance diameter, gun phase and jet penetration. API tests are done on perforating guns to define applicability and performance. A new geometrical parameter is defined as the relative angle of the jet, which is the angle between the jet tunnel and formation dip. GEOCAN is a methodology which relates geology to gun geometry and type to define the most efficient gun system for perforated completions. It uses the intelligent perforating technique with the SPAN (Schlumberger Perforating Analysis) program to confirm optimum gun choice.
Modeling Supercritical Carbon Dioxide Injection in Heterogeneous Porous Media
Doughty, Christine; Pruess, Karsten
We investigate the physical processes that occur during the sequestration of carbon dioxide (CO2) in liquid-saturated, brine-bearing geologic formations using the numerical simulator TOUGH2. CO2 is injected in a supercritical state that has a much lower density and viscosity than the liquid brine it displaces. In situ, the supercritical CO2 forms a gas-like phase, and also partially dissolves in the aqueous phase, creating a multi-phase, multi-component environment that shares many important features with the vadose zone. The flow and transport simulations employ an equation of state package that treats a two-phase (liquid, gas), three-component (water, salt, CO2) system. Chemical reactions between CO2 and rock minerals that could potentially contribute to mineral trapping of CO2 are not included. The geological setting considered is a fluvial/deltaic formation that is strongly heterogeneous, making preferential flow a significant effect, especially when coupled with the strong buoyancy forces acting on the gas-like CO2 plume. Key model development issues include vertical and lateral grid resolution, grid orientation effects, and the choice of characteristic curves.
Method of analysis at the U.S. Geological Survey California Water Science Center, Sacramento Laboratory - determination of haloacetic acid formation potential, method validation, and quality-control practices
Zazzi, Barbara C.; Crepeau, Kathryn L.; Fram, Miranda S.; Bergamaschi, Brian A.
An analytical method for the determination of haloacetic acid formation potential of water samples has been developed by the U.S. Geological Survey California Water Science Center Sacramento Laboratory. The haloacetic acid formation potential is measured by dosing water samples with chlorine under specified conditions of pH, temperature, incubation time, darkness, and residual-free chlorine. The haloacetic acids formed are bromochloroacetic acid, bromodichloroacetic acid, dibromochloroacetic acid, dibromoacetic acid, dichloroacetic acid, monobromoacetic acid, monochloroacetic acid, tribromoacetic acid, and trichloroacetic acid. They are extracted, methylated, and then analyzed using a gas chromatograph equipped with an electron capture detector. Method validation experiments were performed to determine the method accuracy, precision, and detection limit for each of the compounds. Method detection limits for these nine haloacetic acids ranged from 0.11 to 0.45 microgram per liter. Quality-control practices include the use of blanks, quality-control samples, calibration verification standards, surrogate recovery, internal standard, matrix spikes, and duplicates.
The geologically recent giant impact basins at Vesta's south pole.
Schenk, Paul; O'Brien, David P; Marchi, Simone; Gaskell, Robert; Preusker, Frank; Roatsch, Thomas; Jaumann, Ralf; Buczkowski, Debra; McCord, Thomas; McSween, Harry Y; Williams, David; Yingst, Aileen; Raymond, Carol; Russell, Chris
Dawn's global mapping of Vesta reveals that its observed south polar depression is composed of two overlapping giant impact features. These large basins provide exceptional windows into impact processes at planetary scales. The youngest, Rheasilvia, is 500 kilometers wide and 19 kilometers deep and finds its nearest morphologic analog among large basins on low-gravity icy satellites. Extensive ejecta deposits occur, but impact melt volume is low, exposing an unusual spiral fracture pattern that is likely related to faulting during uplift and convergence of the basin floor. Rheasilvia obliterated half of another 400-kilometer-wide impact basin, Veneneia. Both basins are unexpectedly young, roughly 1 to 2 billion years, and their formation substantially reset Vestan geology and excavated sufficient volumes of older compositionally heterogeneous crustal material to have created the Vestoids and howardite-eucrite-diogenite meteorites. PMID:22582256
Geology Fieldnotes: Capitol Reef National Park, Utah
NSDL National Science Digital Library
This Capitol Reef National Park site contains park geology information, park maps, photographs, visitor information, and a teacher feature (resources for teaching geology with National Park examples). Geologic data includes descriptions of the Waterpocket Fold, a monocline formed in the Laramide Orogeny and made of sedimentary rock. Also covered is erosion, and details about the Cathedral Valley outcrop of gypsum. This formation is Permian to Cretaceous in age (270-80 million years old).
NSDL National Science Digital Library
The study of geology at the University of Colorado has a long and distinguished history, and in recent years they have also become increasingly interested in providing online teaching resources in the field. Educators will be glad to learn about this site's existence, as they can scroll through a list of interactive demonstrations that can be utilized in the classroom. Specifically, these demonstrations include a shaded interactive topographical map of the western United States, a magnetic field of the Earth, and several animated maps of various National Park sites. The site comes to a compelling conclusion with the inclusion of the geology department's slide library, which can be used without a password or registration.
NSDL National Science Digital Library
Stephen Nelson
This Tulane University course covers the nature of the Earth, the development of its surficial features, and the results of the interaction of chemical, physical, and biological factors on the planet. Lecture notes are about energy and minerals; igneous, metamorphic and sedimentary rocks; weathering and soils; geologic time; mass wasting; streams; groundwater; wind action and deserts; oceans; deformation of rock; earthquakes and the interior of the Earth; global tectonics; planetary changes; and glaciers.
Geology Fieldnotes: Isle Royale National Park, Michigan
NSDL National Science Digital Library
This National Park Service (NPS) website examines the geology of Isle Royale National Park in Michigan. It looks at the geologic history of this archipelago, beginning 1.2 billion years ago and progressing through volcanics, rock formations and copper deposits, to the Ice Age. There are links to park maps, visitor information, and additional resources.
Geology Fieldnotes: Zion National Park, Utah
NSDL National Science Digital Library
Annabelle Foos
Zion is located on the edge of the Colorado Plateau, and is part of a formation known as the Grand Staircase (Bryce Canyon and the Grand Canyon are also part of this formation). The site discusses the formation of the park, from sedimentation 240 million years ago (Triassic), to lithification, uplift, and erosion. Visible formations include the Navajo sandstone and the Kaibab formation. Additional resources include visitor information, maps, photographs, and a teacher feature (lessons for teaching geology with National Parks as examples).
Formation of magmatic crust at the Andean continental margin during early Mesozoic: a geological and thermal model of the North Chilean Coast Range
NASA Astrophysics Data System (ADS)
Lucassen, F.; Fowler, C. M. R.; Franz, G.
The Pacific margin of South America has existed since at least the Early Paleozoic, developing a diversified continental crust. In the Triassic and Jurassic, mantle-derived plutonic and volcanic rocks, formed a ca. 100-km-wide belt of new magmatic crust in the coast range of northern Chile. The tectonic regime was extensional Surface geology, seismic velocities and the gravity field indicate that the magmatic rocks in the upper 20 km of the crust have a mainly basic composition. The Pre-Andean continental crust is only preserved in isolated small areas, but the rifting had no proveable influence on the surface elevation of the area, which was always above or close to sea level. The coastal magmatic belt marks the onset of the Andean Cycle and was its most intensive phase of magmatic additons to the crust. Numerical experiments were performed using a two-dimensional finite difference grid, with spatial relations derived from the geological model. The duration of two phases of extension and contemporaneous compensation of the crustal thinning by magmatic accretion and the location of the extension in the lithosphere were varied in order to evaluate the duration of the tectonic-magmatic phases, and to distinguish between the effects of tectonic movements and magmatic additions on temperature gradient and elevation. The effect of these two first order heat advection processes on the thermal structure of the lithosphere depends on their duration. It is possible to set reasonable constraints on the duration of extension by comparing calculated temperature distributions with geological data. The temperature distribution in the crust is dominated by processes in the crust and only to a minor extent by deep-seated thermal anomalies. Surface elevation is largely controlled by deep-seated thermal anomalies in the mantle if the thickness of the crust is held constant by magmatic accretion during extension. The time scale of the tectonic-magmatic processes has minor influence on the calculated elevation.
Historical Geology Online Laboratory Manual
NSDL National Science Digital Library
Pamela Gore
The laboratories in this manual cover the following topics: rocks and minerals, weathering of rocks and the formation of sediment, sedimentary rocks and structures, depositional sedimentary environments, sand sieve analysis, relative dating, stratigraphy and lithologic correlation, fossils on the Internet, invertebrate macrofossils, microfossils, preservation, biostratigraphy, evolution, vertebrate paleontology, and interpreting geologic history from maps.
NASA Technical Reports Server (NTRS)
Yingst, R. A.; Mest, S. C.; Berman, D. C.; Garry, W. B.; Williams, D. A.; Buczkowski, D.; Jaumann, R.; Pieters, C. M.; De Sanctis, M. C.; Frigeri, A.; Le Corre, L.; Preusker, F.; Raymond, C. A.; Reddy, V.; Russell, C. T.; Roatsch, T.; Schenk, P. M.
We report on a preliminary global geologic map of Vesta, based on data from the Dawn spacecraft's High- Altitude Mapping Orbit (HAMO) and informed by Low-Altitude Mapping Orbit (LAMO) data. This map is part of an iterative mapping effort; the geologic map has been refined with each improvement in resolution. Vesta has a heavily-cratered surface, with large craters evident in numerous locations. The south pole is dominated by an impact structure identified before Dawn's arrival. Two large impact structures have been resolved: the younger, larger Rheasilvia structure, and the older, more degraded Veneneia structure. The surface is also characterized by a system of deep, globe-girdling equatorial troughs and ridges, as well as an older system of troughs and ridges to the north. Troughs and ridges are also evident cutting across, and spiraling arcuately from, the Rheasilvia central mound. However, no volcanic features have been unequivocally identified. Vesta can be divided very broadly into three terrains: heavily-cratered terrain; ridge-and-trough terrain (equatorial and northern); and terrain associated with the Rheasilvia crater. Localized features include bright and dark material and ejecta (some defined specifically by color); lobate deposits; and mass-wasting materials. No obvious volcanic features are evident. Stratigraphy of Vesta's geologic units suggests a history in which formation of a primary crust was followed by the formation of impact craters, including Veneneia and the associated Saturnalia Fossae unit. Formation of Rheasilvia followed, along with associated structural deformation that shaped the Divalia Fossae ridge-and-trough unit at the equator. Subsequent impacts and mass wasting events subdued impact craters, rims and portions of ridge-and-trough sets, and formed slumps and landslides, especially within crater floors and along crater rims and scarps. Subsequent to the formation of Rheasilvia, discontinuous low-albedo deposits formed or were emplaced; these lie stratigraphically above the equatorial ridges that likely were formed by Rheasilvia. The last features to be formed were craters with bright rays and other surface mantling deposits. Executed progressively throughout data acquisition, the iterative mapping process provided the team with geologic proto-units in a timely manner. However, interpretation of the resulting map was hampered by the necessity to provide the team with a standard nomenclature and symbology early in the process. With regard to mapping and interpreting units, the mapping process was hindered by the lack of calibrated mineralogic information. Topography and shadow played an important role in discriminating features and terrains, especially in the early stages of data acquisition.
NASA Astrophysics Data System (ADS)
Yingst, R. A.; Mest, S. C.; Berman, D. C.; Garry, W. B.; Williams, D. A.; Buczkowski, D.; Jaumann, R.; Pieters, C. M.; De Sanctis, M. C.; Frigeri, A.; Le Corre, L.; Preusker, F.; Raymond, C. A.; Reddy, V.; Russell, C. T.; Roatsch, T.; Schenk, P. M.
We report on a preliminary global geologic map of Vesta, based on data from the Dawn spacecraft's High-Altitude Mapping Orbit (HAMO) and informed by Low-Altitude Mapping Orbit (LAMO) data. This map is part of an iterative mapping effort; the geologic map has been refined with each improvement in resolution. Vesta has a heavily-cratered surface, with large craters evident in numerous locations. The south pole is dominated by an impact structure identified before Dawn's arrival. Two large impact structures have been resolved: the younger, larger Rheasilvia structure, and the older, more degraded Veneneia structure. The surface is also characterized by a system of deep, globe-girdling equatorial troughs and ridges, as well as an older system of troughs and ridges to the north. Troughs and ridges are also evident cutting across, and spiraling arcuately from, the Rheasilvia central mound. However, no volcanic features have been unequivocally identified. Vesta can be divided very broadly into three terrains: heavily-cratered terrain; ridge-and-trough terrain (equatorial and northern); and terrain associated with the Rheasilvia crater. Localized features include bright and dark material and ejecta (some defined specifically by color); lobate deposits; and mass-wasting materials. No obvious volcanic features are evident. Stratigraphy of Vesta's geologic units suggests a history in which formation of a primary crust was followed by the formation of impact craters, including Veneneia and the associated Saturnalia Fossae unit. Formation of Rheasilvia followed, along with associated structural deformation that shaped the Divalia Fossae ridge-and-trough unit at the equator. Subsequent impacts and mass wasting events subdued impact craters, rims and portions of ridge-and-trough sets, and formed slumps and landslides, especially within crater floors and along crater rims and scarps. Subsequent to the formation of Rheasilvia, discontinuous low-albedo deposits formed or were emplaced; these lie stratigraphically above the equatorial ridges that likely were formed by Rheasilvia. The last features to be formed were craters with bright rays and other surface mantling deposits. Executed progressively throughout data acquisition, the iterative mapping process provided the team with geologic proto-units in a timely manner. However, interpretation of the resulting map was hampered by the necessity to provide the team with a standard nomenclature and symbology early in the process. With regard to mapping and interpreting units, the mapping process was hindered by the lack of calibrated mineralogic information. Topography and shadow played an important role in discriminating features and terrains, especially in the early stages of data acquisition.
Xu, Tianfu
Human activities are increasingly altering the Earth's climate. A particular concern is that atmospheric concentrations of carbon dioxide (CO{sub 2}) may be rising fast because of increased industrialization. CO{sub 2} is a so-called ''greenhouse gas'' that traps infrared radiation and may contribute to global warming. Scientists project that greenhouse gases such as CO{sub 2} will make the arctic warmer, which would melt glaciers and raise sea levels. Evidence suggests that climate change may already have begun to affect ecosystems and wildlife around the world. Some animal species are moving from one habitat to another to adapt to warmer temperatures. Future warming is likely to exceed the ability of many species to migrate or adjust. Human production of CO{sub 2} from fossil fuels (such as at coal-fired power plants) is not likely to slow down soon. It is urgent to find somewhere besides the atmosphere to put these increased levels of CO{sub 2}. Sequestration in the ocean and in soils and forests are possibilities, but another option, sequestration in geological formations, may also be an important solution. Such formations could include depleted oil and gas reservoirs, unmineable coal seams, and deep saline aquifers. In many cases, injection of CO2 into a geological formation can enhance the recovery of hydrocarbons, providing value-added byproducts that can offset the cost of CO{sub 2} capture and sequestration. Before CO{sub 2} gas can be sequestered from power plants and other point sources, it must be captured. CO{sub 2} is also routinely separated and captured as a by-product from industrial processes such as synthetic ammonia production, H{sub 2} production, and limestone calcination. Then CO{sub 2} must be compressed into liquid form and transported to the geological sequestration site. Many power plants and other large emitters of CO{sub 2} are located near geological formations that are amenable to CO{sub 2} sequestration.
Analysis of 3d complex structure and heterogeneity effects on formation and propagation of regional phases in Eurasia. Final report, 15 August 1992-30 September 1994
Lay, T.; Wu, R.S.
This document is the final report for this grant to develop new three-dimensional wave propagation techniques for high frequency waves in heterogeneous media. The report is divided into four sections, each being a published paper sponsored by this grant. In the first section we formulate a one-way wide-angle elastic wave propagation method for arbitrarily heterogeneous media in both the space and wavenumber domains using elastic Rayleigh integrals and local elastic Born scattering theory. In the second section this complex phase screen method is compared with fourth-order finite differences and exact eigenfunction expansion calculations for two-dimensional inhomogeneous media to assess the accuracy of the one-way propagation algorithm. In the third section, an observational study of continental margin structure influence on Lg propagation is presented, using data from the former Soviet stations for nuclear explosions at Novaya Zemlya. We find that bathymetric features can be correlated with energy levels of Lg, suggesting that waveguide structure influences regional phase energy partitioning. This idea is pursued in the fourth section, using Eurasian earthquake and nuclear explosion data along with information about the crustal structure in Eurasia. We develop empirical relations that reduce the scatter in the P/Lg discriminant at low frequency.
Well-Production Data and Gas-Reservoir Heterogeneity -- Reserve Growth Applications
Dyman, Thaddeus S.; Schmoker, James W.
Oil and gas well production parameters, including peakmonthly production (PMP), peak-consecutive-twelve month production (PYP), and cumulative production (CP), are tested as tools to quantify and understand the heterogeneity of reservoirs in fields where current monthly production is 10 percent or less of PMP. Variation coefficients, defined as VC= (F5-F95)/F50, where F5, F95, and F50 are the 5th, 95th, and 50th (median) fractiles of a probability distribution, are calculated for peak and cumulative production and examined with respect to internal consistency, type of production parameter, conventional versus unconventional accumulations, and reservoir depth. Well-production data for this study were compiled for 69 oil and gas fields in the Lower Pennsylvanian Morrow Formation of the Anadarko Basin, Oklahoma. Of these, 47 fields represent production from marine clastic facies. The Morrow data were supplemented by data from the Upper Cambrian and Lower Ordovician Arbuckle Group, Middle Ordovician Simpson Group, Middle Pennsylvanian Atoka Formation, and Silurian and Lower Devonian Hunton Group of the Anadarko Basin, one large gas field in Upper Cretaceous reservoirs of north-central Montana (Bowdoin field), and three areas of the Upper Devonian and Lower Mississippian Bakken Formation continuous-type (unconventional) oil accumulation in the Williston Basin, North Dakota and Montana. Production parameters (PMP, PYP, and CP) measure the net result of complex geologic, engineering, and economic processes. Our fundamental hypothesis is that well-production data provide information about subsurface heterogeneity in older fields that would be impossible to obtain using geologic techniques with smaller measurement scales such as petrographic, core, and well-log analysis. Results such as these indicate that quantitative measures of production rates and production volumes of wells, expressed as dimensionless variation coefficients, are potentially valuable tools for documenting reservoir heterogeneity in older fields for field redevelopment and risk analysis.
NSDL National Science Digital Library
This Classroom Connectors lesson plan discusses the characteristics of geologic time, including the law of superposition, fossil preservation, casts and molds, and various events through the history of the Earth. The site provides goals, objectives, an outline, time required, materials, activities, and closure ideas for the lesson. The Classroom Connectors address content with an activity approach while incorporating themes necessary to raise the activity to a higher cognition level. The major motivation is to employ instructional strategies that bring the students physically and mentally into touch with the science they are studying.
Geology Fieldnotes: Grand Teton National Park, Wyoming
NSDL National Science Digital Library
This National Park Service resource includes information about geology, park maps, visitor information, photographs, and links to other sites about this park. Geologic information spans the entire history of the park, beginning 2.5 billion years ago (Precambrian) to the present. Details about the different rock types and their formation, mountain building through plate tectonics and the Laramide Orogeny, formation of valleys and canyons, volcanism in the area, and erosion by glaciers are all covered.
Method of Analysis by the U.S. Geological Survey California District Sacramento Laboratory?Determination of Trihalomethane Formation Potential, Method Validation, and Quality-Control Practices
Crepeau, Kathryn L.; Fram, Miranda S.; Bush, Noel
An analytical method for the determination of the trihalomethane formation potential of water samples has been developed. The trihalomethane formation potential is measured by dosing samples with chlorine under specified conditions of pH, temperature, incubation time, darkness, and residual-free chlorine, and then analyzing the resulting trihalomethanes by purge and trap/gas chromatography equipped with an electron capture detector. Detailed explanations of the method and quality-control practices are provided. Method validation experiments showed that the trihalomethane formation potential varies as a function of time between sample collection and analysis, residual-free chlorine concentration, method of sample dilution, and the concentration of bromide in the sample.
Illinois State Geological Survey
NSDL National Science Digital Library
The Illinois State Geological Survey (ISGS) homepage provides information on geologic mapping, earthquakes, fossils, groundwater, wetlands, glacial geology, bedrock geology, and Lake Michigan geology. Educational materials include field trip guides, short publications on Illinois geology for students and teachers, online tours, single-page maps, and a geologic column. Other materials include databases and collections of GIS data, well records, drill cores, and mining information; a bibliography of Illinois geology; online maps and data; and information on water and land use, resource development, and geologic hazards.
Geology Fieldnotes: Sleeping Bear Dunes National Lakeshore, Michigan
NSDL National Science Digital Library
The Sleeping Bear Dunes National Lakeshore site contains park geology information, park maps, photographs, related links, and visitor information. The park geology section discusses the geologic history of the region and formation of Sleeping Bear Dunes through westerly winds from Lake Michigan. The park maps section includes a map of the Sleeping Bear Dunes National Lakeshore and the surrounding area.
Excerpts from selected LANDSAT 1 final reports in geology
NASA Technical Reports Server (NTRS)
Short, N. M.; Smith, A.; Baker, R.
The standard formats for the summaries of selected LANDSAT geological data are presented as checklists. These include: (1) value of LANDSAT data to geology, (2) geologic benefits, (3) follow up studies, (4) cost benefits, (5) optimistic working scales, (6) statistical analysis, and (7) enhancement effects.
Unraveling Geological History: Glaciers and Faults at Discovery Park, Seattle
NSDL National Science Digital Library
Trileigh Tucker
This introductory geology field exercise asks students to make individual observations about parts of an outcrop, then combine their observations in larger teams to interpret the overall geological history of the exposure. Content learning includes stratigraphy, faulting, and local geologic history; process learning includes data gathering and recording, hypothesis formation, and outlining helpful evidence that could be gathered in the future.
The Necessity of Geologic Disposal
R. Linden
Nuclear wastes are the radioactive byproducts of nuclear power generation, nuclear weapons production, and other uses of nuclear material. Experts from around the world agree that deep geologic disposal of nuclear waste in a mined repository is the most environmentally sound means of removing these potential sources of radiation from interaction with the biosphere. Of the 360 millirem of background radiation received annually by the average American, from both natural and man-made sources, less than 1 millirem results from the nuclear fuel cycle. Spent nuclear fuel and high-level radioactive waste, destined for geologic disposal, are located at 126 sites in 39 states. The proposed repository site at Yucca Mountain, Nevada, is far more isolated from the general population than any sites where these radioactive materials are presently located. Only solid forms of high-level wastes will be transported for disposal in a geologic repository. For more than 50 years, nuclear materials have been safely transported in North America, Europe, and Asia, without a single significant radiation release. Since the 1950s, select panels from the National Academy of Sciences-National Research Council and interagency advisory groups, and international experts selected by the OECD/Nuclear Energy Agency, have examined the environmental, ethical, and intergenerational aspects of nuclear waste disposal, plus alternatives to geologic disposal. All have concluded that deep geologic disposal in a mined repository is clearly the preferred option. The concept of deep geologic disposal is based on the analogy to ore deposits, which are formed deep within the Earth's crust, commonly remain isolated from the biosphere for millions to billions of years, and are, generally, extremely difficult to detect. Before selecting the unsaturated tuffs at Yucca Mountain, DOE evaluated salt formations, basalts, and both crystalline and sedimentary rocks. Other nations generating nuclear power also plan to use deep geologic disposal, and are evaluating sites in granites, argillaceous rocks, and salt formations.
The Geologic Story of Yosemite Valley
NSDL National Science Digital Library
N. Huber
This website of the United States Geological Survey (USGS) and the National Park Service (NPS) discusses the geology of Yosemite Valley in California, beginning 100 million years ago with the formation of the granite rocks found in this park and continuing with jointing, exfoliation, and erosion through ice and water. Bedrock Geology includes details about the formation, classification, and descriptions of the plutonic bedrock. It also discusses the relationship of landforms to rock composition and structure and their role in shaping the Yosemite valley.
Mineralization and other geologic factors related to the Morrison Formation in particular the northern two-thirds of the Colorado Plateau region; basic data and factor-analysis results
Cadigan, Robert Allen
A vanadium-mercury mineralization factor and five other significant geologic factors were determined by multivariate factor analysis of data for Morrison Formation rock samples from the Colorado Plateau region. The data presented in the report were obtained from an agglomeration of 876 samples which yielded a correlation matrix of 44 variables. The variables consisted of geochemical, petrographic, and geographic location parameters. Mineralization factor scores demonstrate the relative intensity of mineralization in rock samples collected in and around uranium-vanadium ore deposits. The factors affecting composition and texture of the rocks identified from the analysis are: (1) metalliferous mudstones; (2) interstitial carbonate cements; (3) competing sources of different composition; (4) heavy mineral sources; (5) vanadium mineralization; and (6) regional and stratigraphic sampling bias.
Coal geology of the Paleocene-Eocene Calvert Bluff Formation (Wilcox Group) and the Eocene Manning Formation (Jackson Group) in east-central Texas; field trip guidebook for the Society for Organic Petrology, Twelfth Annual Meeting, The Woodlands, Texas, August 30, 1995
Warwick, Peter D.; Crowley, Sharon S.
The Jackson and Wilcox Groups of eastern Texas (fig. 1) are the major lignite producing intervals in the Gulf Region. Within these groups, the major lignite-producing formations are the Paleocene-Eocene Calvert Bluff Formation (Wilcox) and the Eocene Manning Formation (Jackson). According to the Keystone Coal Industry Manual (Maclean Hunter Publishing Company, 1994), the Gulf Coast basin produces about 57 million short tons of lignite annually. The state of Texas ranks number 6 in coal production in the United States. Most of the lignite is used for electric power generation in mine-mouth power plant facilities. In recent years, particular interest has been given to lignite quality and the distribution and concentration of about a dozen trace elements that have been identified as potential hazardous air pollutants (HAPs) by the 1990 Clean Air Act Amendments. As pointed out by Oman and Finkelman (1994), Gulf Coast lignite deposits have elevated concentrations of many of the HAPs elements (Be, Cd, Co, Cr, Hg, Mn, Se, U) on a as-received gm/mmBtu basis when compared to other United States coal deposits used for fuel in thermo-electric power plants. Although regulations have not yet been established for acceptable emissions of the HAPs elements during coal burning, considerable research effort has been given to the characterization of these elements in coal feed stocks. The general purpose of the present field trip and of the accompanying collection of papers is to investigate how various aspects of east Texas lignite geology might collectively influence the quality of the lignite fuel. We hope that this collection of papers will help future researchers understand the complex, multifaceted interrelations of coal geology, petrology, palynology and coal quality, and that this introduction to the geology of the lignite deposits of east Texas might serve as a stimulus for new ideas to be applied to other coal basins in the U.S. and abroad.
Subsurface geology and porosity distribution, Madison Limestone and underlying formations, Powder River basin, northeastern Wyoming and southeastern Montana and adjacent areas
Peterson, James A.
To evaluate the Madison Limestone and associated rocks as potential sources for water supplies in the Powder River Basin and adjacent areas, an understanding of the geologic framework of these units, their lithologic facies patterns, the distribution of porosity zones, and the relation between porosity development and stratigraphic facies is necessary. Regionally the Madison is mainly a fossiliferous limestone. However, in broad areas of the eastern Rocky Mountains and western Great Plains, dolomite is a dominant constituent and in places the Madison is almost entirely dolomite. Within these areas maximum porosity development is found and it seems to be related to the coarser crystalline dolomite facies. The porosity development is associated with tabular and fairly continuous crystalline dolomite beds separated by non-porous limestones. The maximum porosity development in the Bighorn Dolomite, as in the Madison, is directly associated with the occurrence of a more coarsely crystalline sucrosic dolomite facies. Well data indicate, however, that where the Bighorn is present in the deeper parts of the Powder River Basin, it may be dominated by a finer crystalline dolomite facies of low porosity. The 'Winnipeg Sandstone' is a clean, generally well-sorted, medium-grained sandstone. It shows good porosity development in parts of the northern Powder River Basin and northwestern South Dakota. Because the sandstone is silica-cemented and quartzitic in areas of deep burial, good porosity is expected only where it is no deeper than a few thousand feet. The Flathead Sandstone is a predominantly quartzose, slightly feldspathic sandstone, commonly cemented with iron oxide. Like the 'Winnipeg Sandstone,' it too is silica-cemented and quartzitic in many places so that its porosity is poor in areas of deep burial. Illustrations in this report show the thickness, percent dolomite, and porosity-feet for the Bighorn Dolomite and the Madison Limestone and its subdivisions. The porosity-feet for the 'Winnipeg' and Flathead Sandstones and four regional geologic sections are also shown.
NSDL National Science Digital Library
This document describes how geologic time is approached in discussions of geologic topics. The uses of relative time and absolute time are compared, and a geologic time scale is provided to represent both concepts. References are provided.
Geologic Technician New Curriculum
ERIC Educational Resources Information Center
Karp, Stanley E.
Describes a developing two-year geologic technician program at Bakersfield College in which a student may major in five areas - geologic drafting, land and legal, geologic assistant, engineering or paleontology. (RR)
The proposed activities will yield the formulation of parameterizations that can be incorporated into SOA models that will lead to improvement in the ability to simulate isoprene SOA formation in the southeastern U. S. Specific results include: (1) characterization of reaction...
Geologic structure and altitude of the top of the Minnelusa Formation, northern Black Hills, South Dakota and Wyoming, and Bear Lodge Mountains, Wyoming
Peter, Kathy D.; Kyllonen, David P.; Mills, K.R.
Beginning in 1981, a 3-yr project was conducted to determine the availability and quality of groundwater in the sedimentary bedrock aquifers in the Black Hills of South Dakota and Wyoming. The project was limited to three bedrock units in order of increasing age: the Cretaceous Inyan kara Group, Permian and Pennsylvanian Minnelusa Formation, and Mississippian Madison (or Pahasapa) Limestone. This map shows the altitude of the top of the Minnelusa Formation in the northern Black Hills, and shows the configuration of the structural features in the northern part of the Black Hills and the eastern part of the Bear Lodge Mountains. In general, the Minnelusa Formation dips away from the Black Hills uplift, either to the northeast and the Williston Basin or, south of the Bear Lodge Mountains, to the southwest and the Powder River basin, which is outside the map area. In the map area, the upper beds of the Minnelusa Formation are an aquifer and the lower beds are a confining or semi-confining unit. The upper part of the Minnelusa Formation has a greater percentage of coarse-grained sandstone beds than the lower part. Furthermore, solution and removal of anhydrite, brecciation, and solution of cement binding the sandstone grains may have increased the permeability of the upper part of the Minnelusa Formation in the Black Hills. Wells completed in the upper part of the Minnelusa have yields that exceed 100 gal/min in some areas and at least one large diameter well is reported to flow 1,000 gal/min in some areas and at least one large diameter well is reported to flow 1,000 gal/min. Flowing wells have been completed in the Minnelusa aquifer in most of the study area in South Dakota and in about the northern one-half of Crook County, Wyoming. (Lantz-PTT)
Geology Fieldnotes: Carlsbad Caverns National Park, New Mexico
NSDL National Science Digital Library
Carlsbad Caverns National Park has been designated as a world heritage site because of its unique and surprising geology. Site features include park geology information, maps, photographs, related links, and visitor information. The park geology section discusses the caverns' geologic history, mineral formations, and preservation. The maps section includes a map of the Carlsbad Caverns National Park itself and a link to a map of the surrounding area.
NSDL National Science Digital Library
Germari De Villiers
This lab is part of a Lunar and Planetary Geology course offered to both geology and non-geology majors, and it involves basic geological mapping of an area within the Tyrrhena Patera region on Mars. Students are encouraged to work in groups to prepare a geological map from a photomosaic map and to interpret the geologic stratigraphy from a geological map of the greater area. This activity reinforces mapping skills as well as group work skills, and aims to teach students more about Martian stratigraphy and geology through a hands-on activity.
Detailed geologic field mapping and radiometric dating of the Abanico Formation in the Principal Cordillera, central Chile: Evidence of protracted volcanism and implications for Cenozoic tectonics
NASA Astrophysics Data System (ADS)
Mosolf, J.; Gans, P. B.; Wyss, A. R.; Cottle, J. M.
Many aspects of the long-term evolution of intra-arc processes remain poorly understood, including temporal trends in magmatism, temporal and spatial patterns of volcanism, and styles of arc deformation. The Abanico Formation in the Principal Cordillera of central Chile is a thick, well-exposed section of volcanogenic strata providing a superb locale for the investigation of continental arc dynamics over a 60+ myr timescale. In this study, eight new litho-stratigraphic members of the Abanico Formation are described and mapped in the RĒo Tinguiririca river area. Mapping and field observations show the Abanico Formation measures up to ~2.5 km in composite stratigraphic thickness. The lower ~1.1 km of the section (> 46 Ma) is dominated by andesitic breccias interbedded with andesite, basaltic andesite, and olivine basalt lavas. The upper 1.4 km of the section (< 46 Ma) consists of volcaniclastic sandstone interbedded with abundant dacitic tuffs and minor andesite, basaltic andesite, and basalt flows. Nineteen new LA-MC-ICPMS U-Pb zircon ages and ten new 40Ar/39Ar whole rock and plagioclase ages obtained for the Abanico Formation clarify ambiguous field relationships and provide a robust chrono-stratigraphic framework spanning ~72 to 11 Ma; these new ages significantly revise the maximum mid-Tertiary age for the Abanico Formation previously established by the mammal fossil record. The map units are cut by numerous dacitic to gabbroic dikes and sills with ages spanning the Eocene to Pliocene. The Abanico Formation is overlain in angular unconformity by Pliocene and Quaternary volcanics composed mainly of andesite, basaltic andesite, and basalt lavas. A strong deformational overprint has tilted, folded, and faulted the Abanico map units. Fold axes and reverse faults, both east and west directed, are generally N-S trending. Reverse faults achieve up to ~50 Ma of stratigraphic separation, placing Campanian strata on Miocene rocks with up to ~2 km of vertical throw. The Abanico Formation is also offset by numerous steeply-dipping, oblique-slip faults with 100+ meters of slip. The Abanico Formation is interpreted to have been emplaced within an active arc, with progressively more evolved material being erupted up section during the Campanian to Miocene, followed by more mafic volcanism during the Pliocene and Quaternary. Radiometric ages bounding intra-formational unconformities imply that shortening commenced no later than the early Miocene, with an older deformational episode possibly preceding it. Results of this study clearly demonstrate the age of the Abanico Formation extends from Campanian to Miocene, requiring a significant revision of the current mid-Tertiary age paradigm for the Abanico Formation in addition to the revision of the prevailing tectonic models for the Principal Cordillera, including the timing of eastward arc migration.
Prototype of Partial Cutting Tool of Geological Map Images Distributed by Geological Web Map Service
NASA Astrophysics Data System (ADS)
Nonogaki, S.; Nemoto, T.
Geological maps and topographical maps play an important role in disaster assessment, resource management, and environmental preservation. These map information have been distributed in accordance with Web services standards such as Web Map Service (WMS) and Web Map Tile Service (WMTS) recently. In this study, a partial cutting tool of geological map images distributed by geological WMTS was implemented with Free and Open Source Software. The tool mainly consists of two functions: display function and cutting function. The former function was implemented using OpenLayers. The latter function was implemented using Geospatial Data Abstraction Library (GDAL). All other small functions were implemented by PHP and Python. As a result, this tool allows not only displaying WMTS layer on web browser but also generating a geological map image of intended area and zoom level. At this moment, available WTMS layers are limited to the ones distributed by WMTS for the Seamless Digital Geological Map of Japan. The geological map image can be saved as GeoTIFF format and WebGL format. GeoTIFF is one of the georeferenced raster formats that is available in many kinds of Geographical Information System. WebGL is useful for confirming a relationship between geology and geography in 3D. In conclusion, the partial cutting tool developed in this study would contribute to create better conditions for promoting utilization of geological information. Future work is to increase the number of available WMTS layers and the types of output file format.
Geology Fieldnotes: Wind Cave National Park South Dakota
NSDL National Science Digital Library
Wind Cave National Park includes one of the world's longest and most complex caves and 28,295 acres of mixed-grass prairie, ponderosa pine forest, and associated wildlife. The cave is well known for its outstanding display of boxwork, an unusual cave formation composed of thin calcite fins resembling honeycombs. Features include park geology information, maps, photographs of cave formations, related links, and visitor information. The park geology section discusses geologic history, structural geology, cave formations, and history of exploration of the region. The park maps section includes an area map of Wind Cave National Park and a detailed cave map.
NASA Technical Reports Server (NTRS)
2003-01-01[figure removed for brevity, see original site] Released 28 May 2003Mangala Vallis one of the large outflow channels that channeled large quantities of water into the northern lowlands, long ago on geological timescales. This valley is one of the few in the southern hemisphere, as well as one of the few west of the Tharsis bulge. A closer look at the channel shows more recent weathering of the old water channel: the walls of the channel show small, dark slope streaks that form in dusty areas; and much of the surrounding terrain has subtle linear markings trending from the upper left to the lower right, which are probably features sculpted and streamlined by the wind. Geology still shapes the surface of Mars today, but its methods over the eons have changed.Image information: VIS instrument. Latitude -6, Longitude 209.6 East (150.4 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.
NSDL National Science Digital Library
The Colorado Geological Survey (CGS) is an agency of state government within the Department of Natural Resources whose mission is to help reduce the impact of geologic hazards on the citizens of Colorado, to promote the responsible economic development of mineral and mineral fuel resources, to provide geologic insight into water resources, and to provide geologic advice and information to a variety of constituencies. This site contains extensive information about Colorado geology such as maps, a geologic time scale for the state, program information, and state field trip information. This site hosts the Avalanche Information Center which contains avalanche forecasting and education center details. Publications report on geologic hazards, land use, environmental geology, mineral resources, oil, gas, coal, geologic mapping and earthquake information for the state. There are online editions of RockTalk, which is a quarterly newsletter published by the Colorado Geological Survey dealing with all aspects of geology throughout the state of Colorado. Links are provided for more resources.
NSDL National Science Digital Library
In this activity students study a map of bedrock geology which describes the types of rocks that exist in a given area. It shows these rock units as well as their known and inferred contacts. Consideration is also given to folding, faulting, unconformities, and similar rock relationships. These features are often included in bedrock geology maps. Students study the legend and scale and become aware of the other information that is included on the map such as the stratigraphic column, list of formations, and inset map of metamorphic grade. Students then locate their city or town and draw a 40-mile diameter circle around it and identify all the symbols inside the circle and the age of the various rocks. Student question sheets are available at this site. Although this activity was written for a map of Maine, it will work in any state where geological maps are available.
Geology of the northern Cleft segment, Juan de Fuca Ridge: Recent lava flows, sea-floor spreading, and the formation of megaplumes
Embley, R.W. (NOAA, Newport, OR (United States)); Chadwick, W. (Oregon State Univ., Newport (United States)); Perfit, M.R. (Univ. of Florida, Gainesville (United States)); Baker, E.T. (Pacific Marine Environmental Lab., Seattle, WA (United States))
Geologic mapping and lava sampling were carried out after the discovery of large bursts of hydrothermal fluids (megaplumes) over the southern Juan de Fuca Ridge in 1986 and 1987. These investigations of the northernmost section of the Cleft segment have discovered: (1) semicontinuous low-temperature venting and one major high-temperature vent site along 17 km of the neovolcanic zone and (2) very glassy, lightly sedimented sheet flows and pillow mounds superimposed on older terrain over about 24 km along the northern-most part. The pillow mounds are documented to have erupted between 1981 and 1987. The occurrence of the megaplumes during this same time period strengthens the hypothesis that megaplumes are caused by sea-floor extension events. Although the basalts from the entire length of the neovolcanic zone of the Cleft segment appear to have been derived from the same mantle source, a systematic northward increase in Mg number along the segment within the neovolcanic zone indicates less shallow-level differentiation to the north, possibly related to the development of new magma chambers during the recent phase of sea-floor spreading that has occurred there.
Ray Lemoine, Cedar Bluffs Public Schools, Cedar Bluffs, NE 2008 Geologic Time
Frank, Tracy D.
Ray Lemoine, Cedar Bluffs Public Schools, Cedar Bluffs, NE ┬® 2008 Geologic Time Materials: Geologic Time Scale Map of Nebraska Bedrock Geology Web access Background: This would make a great introductory lesson to Geologic Time. Students should understand rock formation and weathering. The primary
Geologic Sequestration Studies with Hawaiian Picrites
K. T. Johnson; B. P. McGrail; H. T. Schaef
Capturing and storing anthropogenic carbon dioxide in deep geologic formations is a potential CO2 mitigation solution being studied to reduce adverse effects of increasing greenhouse gas concentrations on the global climate. Basalt formations, widespread globally, are currently being considered as a long term storage option. Because combustion gas streams often contain impurities, it is also important to consider contaminants (e.g.,
Marine geology: A planet earth perspective
Anderson, R.N.
This text provides coverage of the basic geology of the marine development. It starts with the formation of the oceans using plate tectonics, continues with discussions of the mid-ocean ridges, and concludes with coverage of the formation and deformation of the continents.
NSDL National Science Digital Library
This portal provides access to resources on geologic mapping, and to sources of geologic maps. There is an introduction to geologic mapping, which summarizes its principles and practices, and a history of United States Geological Survey (USGS) mapping activities from 1879 to the present, as well as links to papers on the values and hazards associated with geologic maps and mapping. Online sources of maps include the USGS Geologic Map Database, other federal map products (FEDMAP), state geological survey products (STATEMAP), and university map products (EDMAP).
NSDL National Science Digital Library
This is the homepage of the Geology Division of the Tennessee Department of Environment and Conservation. It provides information on the division's programs, including geologic hazards research, public service, education programs, basic and applied research on geology and mineral resources, publication of geologic information, permitting of oil and gas wells, and regulation of Tennessee's oil and gas industry. Materials include a catalog of publications, maps, geologic bulletins, and the Public Information series of pamphlets; the Geology Division Newsletter; and information on the state's mineral industry. There is also a section on the Gray Fossil Site, an unusual assemblage of fossils and sedimentary geology encountered during road construction near the town of Gray, Tenessee.
NSDL National Science Digital Library
The Vermont Geological Survey, also known as the Division of Geology and Mineral Resources in the Department of Environmental Conservation, conducts surveys and research relating to the geology, mineral resources and topography of the State. This site provides details about the states geology with a downloadable state geologic map and key, state rock information, gold in Vermont, fossils found in the state, bedrock mapping details, stream geomorphology, the Champlain thrust fault, earthquakes, radioactive waste and links for additional information.
Toward a quantitative characterization of heterogeneous ice formation with lidar/radar: Comparison of CALIPSO/CloudSat with ground-based observations
NASA Astrophysics Data System (ADS)
B³hl, J.; Ansmann, A.; Seifert, P.; Baars, H.; Engelmann, R.
We analyze and compare the different sensitivities of aerosol/cloud lidar and 35-GHz cloud radar to detect ice formation in midlevel clouds in order to harmonize mixed phase cloud observations performed with lidar and radar. We found good agreement between spaceborne Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO)/CloudSat and ground-based lidar/radar observations at Leipzig, Germany. However, large differences were found to a previous study with an 11-year cloud statistics solely based on lidar observations which is caused by significantly higher sensitivity of the cloud radar to detect ice crystals. By introducing a lidar detection threshold for the ice water content of 10-6kgm-3, we find that lidar and radar cloud statistics become increasingly similar.
Godiva Rim Member: A new stratigraphic unit of the Green River Formation in southwest Wyoming and northwest Colorado. Geology of the Eocene Wasatch, Green River, and Bridger (Washakie) Formations, Greater Green River Basin, Wyoming, Utah, and Colorado. Professional paper
Roehler, H.W.
The report names and describes the Godiva Rim Member of the Green River Formation in the eastern part of the Washakie basin in southwest Wyoming and the central part of the Sand Wash basin in northwest Colorado. The Godiva Rim Member comprises lithofacies of mixed mudflat and lacustrine origin situated between the overlying lacustrine Laney Member of the Green River Formation and the underlying fluvial Cathedral Bluffs Tongue of the Wasatch Formation. The Godiva Rim Member is laterally equivalent to and grades westward into the LaClede Bed of the Laney Member. The Godiva Rim Member of the Green River Formation was deposited along the southeast margins of Lake Gosiute and is correlated to similar lithologic units that were deposited along the northeast margins of Lake Uinta in the Parachute Creek Member of the Green River Formation. The stratigraphic data presented provide significant evidence that the two lakes were periodically connected around the east end of the Uinta Mountains during the middle Eocene.
Modeling geologic storage of carbon dioxide: Comparison ofnon-hysteretic chracteristic curves
Doughty, Christine
TOUGH2 models of geologic storage of carbon dioxide (CO2) in brine-bearing formations use characteristic curves to represent the interactions of non-wetting-phase CO2 and wetting-phase brine. When a problem includes both injection of CO2 (a drainage process) and its subsequent post-injection evolution (a combination of drainage and wetting), hysteretic characteristic curves are required to correctly capture the behavior of the CO2 plume. In the hysteretic formulation, capillary pressure and relative permeability depend not only on the current grid-block saturation, but also on the history of the saturation in the grid block. For a problem that involves only drainage or only wetting, a nonhysteretic formulation, in which capillary pressure and relative permeability depend only on the current value of the grid-block saturation, is adequate. For the hysteretic formulation to be robust computationally, care must be taken to ensure the differentiability of the characteristic curves both within and beyond the turning-point saturations where transitions between branches of the curves occur. Two example problems involving geologic CO2 storage are simulated using non-hysteretic and hysteretic models, to illustrate the applicability and limitations of non-hysteretic methods: the first considers leakage of CO2 from the storage formation to the ground surface, while the second examines the role of heterogeneity within the storage formation.
Seismic Determination of Reservoir Heterogeneity: Application to the Characterization of Heavy Oil Reservoirs
Imhof, Matthias G.; Castle, James W.
The objective of the project was to examine how seismic and geologic data could be used to improve characterization of small-scale heterogeneity and their parameterization in reservoir models. The study was performed at West Coalinga Field in California.
NSDL National Science Digital Library
Marshak, Stephen
From subduction to the world of hot spot volcanoes, this online resource for students and teachers of geology will please users with its fun and useful animations, crossword puzzles, and well-written articles. The site was designed to complement a textbook created by W.W. Norton, but many of the materials can be used as stand-alone exercises. Visitors will want to begin by looking through the visually enticing animations, which cover the Earth's magnetic field, the spread of the sea floor, and the formation of ocean crust. All told, there are over sixty animations, and teachers may wish to recommend them to students. Additionally, visitors should note that they can also browse through the materials offered on the site by clicking on the chapter listings located near the top of the screen. It's hard to pass up a crossword puzzle, and visitors may find themselves spending more time there than at any other part of the site.
Closed-loop Aquifer Management for Geological Carbon Sequestration
NASA Astrophysics Data System (ADS)
Cameron, D. A.; Durlofsky, L. J.
We present a general 'closed-loop' framework that uses prior geological information and measured data to model and periodically optimize (in the sense of risk minimization) CO2 storage operations. The overall goal of the methodology is to determine optimal well locations and settings (e.g., CO2 injection rates for multiple horizontal wells as a function of time) such that an appropriate measure of the risk of leakage is minimized. Here we minimize the fraction of mobile CO2 in the formation, since CO2 in this form may pose the greatest risk of leakage, though other risk measures could be readily considered. We begin with a prior (geostatistical) model of the aquifer. Using multiple realizations sampled from the prior distribution, we determine the optimal well locations, and initial estimates for the optimal time-varying CO2 injection rates, for a set of wells. We also present a procedure for determining the optimal locations of some number of observation wells. Optimality in this context entails placing observation wells such that the expected error in the prediction of the CO2 plume location over a particular time frame is minimized. Data assimilation is accomplished using a Karhunen-Loeve (essentially a principal component analysis) parameterization of the geological model. Our approach thus provides geological models that yield simulation results in close agreement with data from CO2 injectors and observation wells, and also honor the specified geostatistical spatial correlation structure. Noninvasive derivative-free techniques, such as pattern search and particle swarm optimization, are used for the optimization and data assimilation steps. The overall set of procedures is applied to a synthetic heterogeneous aquifer model that includes many of the complexities of a realistic application. Results are presented for the individual modules (minimization of mobile CO2 with prescribed geology, data assimilation) and for the overall closed-loop approach. We show that the use of optimized well locations and settings results in lower mobile CO2 fractions than a heuristic approach. We additionally demonstrate the substantial benefits of 'brine cycling' in which brine is produced and re-injected into the formation at particular (optimized) times. The ability of our data assimilation procedure to provide models in close agreement with observed data of various types is also demonstrated. Finally, we apply the overall closed-loop procedure to illustrate the many benefits of using a data-driven approach for managing CO2 storage operations.
Regional geology of Pierce member of upper Morrow formation in Anadarko basin, with a detailed look at South Dempsey field in Roger Mills County, Oklahoma
Johnson, B.S. (AnSon Gas Co., Oklahoma City, OK (USA))
The members of the upper Morrow formation in the deep Anadarko basin are extremely prolific but elusive targets. The high reserve potential attributable to these reservoirs has been responsible for the ranking of Roger Mills County, Oklahoma, as the leading gas-producing county in the state. The deposition of the Pierce, one of the oldest members of the upper Morrow, was a result of upward movement, during the late Morrowan, of Mississippian Meramec-Osage age sediments along the Amarillo-Wichita uplift, that were unroofed by erosion and deposited as coastal alluvial fans. High-energy traction currents, associated with fluvial channels, carried sediments 10-17 mi northeast, away from the mountain front, and deposited them in sinuous to braided patterns. Textural interpretations from core data of the Pierce show an immature, very poorly sorted conglomerate consisting of medium to coarse-grained quartz sand with pebble to cobble-sized angular and subrounded chert clasts. The Pierce has productive thicknesses ranging from 8 to 60 ft with porosities of 9 to 15% and estimated per-well reserves from 8 to 30 bcf of gas. Although the irregular depositional patterns associated with the Pierce present a challenge to the explorationist, the accompanying prolific production, characteristic of this reservoir, has made it one of the more rewarding targets in Oklahoma. Further understanding of the petrology and depositional environment of the Pierce will aid in the delineation of future exploration plays within both this unit and other members of the upper Morrow formation deposited under similar conditions.
Volcanic geology of Tyrrhena Patera, Mars
NASA Astrophysics Data System (ADS)
Greeley, R.; Crown, D. A.
Consideration is given to the geology of Tyrrhena Patera, a large low-relief volcano in the southern cratered highlands of Mars. The general geology of Tyrrhena Patera is outlined and models for the formation of the volcano are described. Models derived from studies of terrestrial pyroclastic flows are applied to deposits at Tyrrhena Patera, showing that the characteristics of the deposits are consistent with an origin by the emplacement of gravity-driven ash flows generated by hydromagmatic or magmatic explosive eruptions.
Problems of the chemical physics of heterogeneous catalysis
NASA Astrophysics Data System (ADS)
Krylov, Oleg V.
A series of fundamental problems of the chemical physics of heterogeneous catalysis are considered: new methods for investigating the mechanism of heterogeneous catalysis making it possible to study the reaction in situ with a high degree of time resolution; the dynamics of the elementary step, including energy and electron exchange processes in catalysis; macrodynamics of heterogeneous catalysis, including the formation of dissipative structure; chain mechanisms; heterogeneous-homogeneous catalysis and the role of a multiphase structure in heterogeneous catalysis. The bibliography includes 245 references.
Hanford Site Guidelines for Preparation and Presentation of Geologic Information
Lanigan, David C.; Last, George V.; Bjornstad, Bruce N.; Thorne, Paul D.; Webber, William D.
A complex geology lies beneath the Hanford Site of southeastern Washington State. Within this geology is a challenging large-scale environmental cleanup project. Geologic and contaminant transport information generated by several U.S. Department of Energy contractors must be documented in geologic graphics clearly, consistently, and accurately. These graphics must then be disseminated in formats readily acceptable by general graphics and document producing software applications. The guidelines presented in this document are intended to facilitate consistent, defensible, geologic graphics and digital data/graphics sharing among the various Hanford Site agencies and contractors.
Lattice Boltzmann simulation of immiscible fluid displacement in porous media: Homogeneous versus heterogeneous pore network
NASA Astrophysics Data System (ADS)
Liu, Haihu; Zhang, Yonghao; Valocchi, Albert J.
Injection of anthropogenic carbon dioxide (CO2) into geological formations is a promising approach to reduce greenhouse gas emissions into the atmosphere. Predicting the amount of CO2 that can be captured and its long-term storage stability in subsurface requires a fundamental understanding of multiphase displacement phenomena at the pore scale. In this paper, the lattice Boltzmann method is employed to simulate the immiscible displacement of a wetting fluid by a non-wetting one in two microfluidic flow cells, one with a homogeneous pore network and the other with a randomly heterogeneous pore network. We have identified three different displacement patterns, namely, stable displacement, capillary fingering, and viscous fingering, all of which are strongly dependent upon the capillary number (Ca), viscosity ratio (M), and the media heterogeneity. The non-wetting fluid saturation (Snw) is found to increase nearly linearly with logCa for each constant M. Increasing M (viscosity ratio of non-wetting fluid to wetting fluid) or decreasing the media heterogeneity can enhance the stability of the displacement process, resulting in an increase in Snw. In either pore networks, the specific interfacial length is linearly proportional to Snw during drainage with equal proportionality constant for all cases excluding those revealing considerable viscous fingering. Our numerical results confirm the previous experimental finding that the steady state specific interfacial length exhibits a linear dependence on Snw for either favorable (M ? 1) or unfavorable (M < 1) displacement, and the slope is slightly higher for the unfavorable displacement.
A theoretical framework for modeling dilution enhancement of non-reactive solutes in heterogeneous porous media.
de Barros, F P J; Fiori, A; Boso, F; Bellin, A
Spatial heterogeneity of the hydraulic properties of geological porous formations leads to erratically shaped solute clouds, thus increasing the edge area of the solute body and augmenting the dilution rate. In this study, we provide a theoretical framework to quantify dilution of a non-reactive solute within a steady state flow as affected by the spatial variability of the hydraulic conductivity. Embracing the Lagrangian concentration framework, we obtain explicit semi-analytical expressions for the dilution index as a function of the structural parameters of the random hydraulic conductivity field, under the assumptions of uniform-in-the-average flow, small injection source and weak-to-mild heterogeneity. Results show how the dilution enhancement of the solute cloud is strongly dependent on both the statistical anisotropy ratio and the heterogeneity level of the porous medium. The explicit semi-analytical solution also captures the temporal evolution of the dilution rate; for the early- and late-time limits, the proposed solution recovers previous results from the literature, while at intermediate times it reflects the increasing interplay between large-scale advection and local-scale dispersion. The performance of the theoretical framework is verified with high resolution numerical results and successfully tested against the Cape Cod field data. PMID:25795562
Impact of Large-scale Geological Architectures On Recharge
NASA Astrophysics Data System (ADS)
Troldborg, L.; Refsgaard, J. C.; Engesgaard, P.; Jensen, K. H.
Geological and hydrogeological data constitutes the basis for assessment of ground- water flow pattern and recharge zones. The accessibility and applicability of hard ge- ological data is often a major obstacle in deriving plausible conceptual models. Nev- ertheless focus is often on parameter uncertainty caused by the effect of geological heterogeneity due to lack of hard geological data, thus neglecting the possibility of alternative conceptualizations of the large-scale geological architecture. For a catchment in the eastern part of Denmark we have constructed different geologi- cal models based on different conceptualization of the major geological trends and fa- cies architecture. The geological models are equally plausible in a conceptually sense and they are all calibrated to well head and river flow measurements. Comparison of differences in recharge zones and subsequently well protection zones emphasize the importance of assessing large-scale geological architecture in hydrological modeling on regional scale in a non-deterministic way. Geostatistical modeling carried out in a transitional probability framework shows the possibility of assessing multiple re- alizations of large-scale geological architecture from a combination of soft and hard geological information.
NSDL National Science Digital Library
This page from Iowa State University presents a general glossary of geologic terms. The site would be a good reference for geology coursework. This glossary of geologic terms is based on the glossary in Earth: An Introduction to Geologic Change, by S. Judson and S.M. Richardson (Englewood Cliffs, NJ, Prentice Hall, 1995). Where possible, definitions conform generally, and in some cases specifically, to definitions given in Robert L Bates and Julia A Jackson (editors), Glossary of Geology, 3rd ed., American Geological Institute, Alexandria, Virginia, 1987.
A Fundamental Study of Convective Mixing of CO2 in Layered Heterogeneous Saline Aquifers with Low Permeability Zones using Surrogate Fluids and Numerical Modeling
NASA Astrophysics Data System (ADS)
Agartan, E.; Illangasekare, T. H.; Cihan, A.; Birkholzer, J. T.; Zhou, Q.; Trevisan, L.
Dissolution trapping is one of the primary mechanisms contributing to long-term and stable storage of supercritical CO2 (scCO2) in deep saline geologic formations. When entrapped scCO2 dissolves in formation brine, density-driven convective fingers are expected to be generated due to the higher density of the solution compared to brine. These fingers enhance mixing of dissolved scCO2 in brine (Ennis-King & Paterson, 2003). The goal of this study is to evaluate the contribution of convective mixing to dissolution trapping of CO2 in naturally layered heterogeneous formations with low permeability zones via experimental and numerical analyses. To understand the fundamental process of dissolution trapping in the laboratory under ambient pressure and temperature conditions, a group of surrogate fluids were selected according to their density and viscosity values before and after dissolution. Fluids were tested in a variety of porous media systems. After selection of the appropriate fluid mixture based on the closest behavior to scCO2 brine systems, a set of experiments in a small homogeneously packed test tank was performed to analyze the fingering behaviors. A second set of experiments was conducted in the same test tank with layered soil systems to study the effects of formation heterogeneity on convective mixing. A finite volume method based numerical code was developed to capture the dominant processes observed in the experiments. This model was then used to simulate more complex heterogeneous systems that were not represented in the limited set of experiments. Results of these analyses suggest that convective fingers developed in homogeneous formations may not be significantly contributing to mixing and hence dissolution trapping in heterogeneous formations depending on the permeability contrasts and thickness of the low permeability layers.
Geologic characterization and coalbed methane occurrence: Williams Fork Formation, Piceance Basin, Northwest Colorado. Annual report, December 1, 1993-November 30, 1994
Tyler, R.; Kaiser, W.R.; McMurry, R.G.; Nance, H.S.; Scott, A.R.
The coal-bearing Upper Cretaceous Williams Fork Formation, 1,200 to 2,500 ft thick, is operationally defined on the basis of correlation with the Sand Wash Basin. Net coal thickness is typically 80 to 120 ft and is thickest in a north-south belt west of the Divide Creek Anticline. Depositional setting and thrust faults cause coals along the Grand Hogback and in the subsurface to be in modest to poor hydraulic communication. Thus, meteoric recharge and flow basinwind is restricted. Face cleats of Late Cretaceous age strike east-northeast and west-northwest in the southern and northern parts of the basin, respectively, normal to the Hogback thrust front. Parallelism between face-cleat strike and present-day maximum horizontal stress direction may enhance coal permeability in the north. The most productive wells are on structural terraces and anticlines or correspond to Cameo sandstone development, reflecting fracture-enhanced permeability. As predicted, from an evolving coalbed methane producibility model, extraordinary coal-gas production is precluded by the absence of dynamic ground-water flow. The best potential for coal-gas production may lie in conventional traps basinward of where outcrop and subsurface coals are in good hydraulic communication.
Geology and paleoecology of the Cottonwood Creek delta in the Eocene Tipton Tongue of the Green River Formation and a mammalian fauna from the Eocene Cathedral Bluffs Tongue of the Wasatch Formation, Southeast Washakie Basin, Wyoming
Roehler, H.W.; Hanley, J.H.; Honey, J.G.
Nonmarine mollusks are used to interpret paleoenvironments and patterns of sedimentation of a fan delta on the east margin of Eocene Lake Gosiute. The delta is composed of a lens of quartzose sandstone intertongued with oil shale. Delta morphology is illustrated by cross sections and paleogeographic maps. A fossil fauna representing five mammalian orders is described and used to establish the age of parts of the Wasatch and Green River formations. There are three chapters in this bulletin.
Andrei borisovich vistelius: a dominant figure in 20th century mathematical geology
Merriam, D.F.
Andrei Borisovich Vistelius (1915-1995), along with William Christian Krumbein (1902-1979) and John Cedric Griffiths (1912-1992), were dominant figures in the formative and development years of mathematical (or quantitative) geology as a subdiscipline of geology.
Monocyte and macrophage heterogeneity
Philip R. Taylor; Siamon Gordon
Heterogeneity of the macrophage lineage has long been recognized and, in part, is a result of the specialization of tissue macrophages in particular microenvironments. Circulating monocytes give rise to mature macrophages and are also heterogeneous themselves, although the physiological relevance of this is not completely understood. However, as we discuss here, recent studies have shown that monocyte heterogeneity is conserved
Principles of Historical Geology Geology 331
Kammer, Thomas
of a valley can be correlated. Ę This principle is used to trace coal seams from one mountain to the next in West Virginia. #12;Original Lateral Continuity #12;Geology Field Camp in the Badlands of South Dakota Rocks #12;James Hutton, 18th Century founder of Geology #12;Siccar Point, Scotland, where Hutton
Utah Geological Survey: Teaching Geology Resources
NSDL National Science Digital Library
From Arches National Park to the towering cliffs at Castle Rock Campground, Utah has some remarkable geology on display. The Utah Geological Survey decided to draw on these fantastic "outdoor laboratories" and create a set of resources designed for science educators. While some of the resources are geared towards users in Utah, many of the sections contain helpful overviews that will help all educators remain on a steady foundation of geologic knowledge. One key area on the site is the "Earthquakes & Geologic Hazards" section. Here, visitors can find well-composed and straight forward summaries on topics like liquefaction, ground cracks, and fault lines. Moving on to the "Teacher Resources" area, visitors will find the delightful "Glad You Asked" articles and the very useful "Teacher's Corner" column which provides information on reading a stone wall and geologic stretching.
NSDL National Science Digital Library
This Geological Society of America (GSA) site contains a detailed geologic time scale as an educational resource. It may be downloaded to a larger size, and includes all Eras, Eons, Periods, Epochs and ages as well as magnetic polarity information.
Geophysics & Geology Inspected.
ERIC Educational Resources Information Center
Neale, E. R. W.
Summarizes findings of a recently published report of the Canadian Geoscience Council, which includes the following topics regarding college geology: facilities; teaching; undergraduate enrollments; postgraduate enrollments; geologic research; and integration of Canadian geoscience with other countries. (CS)
Thiessen, R.L.; Eliason, J.R.
This report describes the development of geologic spatial analysis research which focuses on conducting comprehensive three-dimensional analysis of regions using geologic data sets that can be referenced by latitude, longitude, and elevation/depth. (CBS)
Seismic response interpretation for heterogeneous reservoir models
Fichtl, P.; Fournier, F. [Institut Francais du Petrole, Rueil-Malmaison (France)
Seismic information is crucial to constrain the reservoir image between wells. However, in heterogeneous environments, it is often difficult to interpret the seismic response of the reservoir, especially with limited well control. Analyses of synthetic seismic responses of typical reservoir models are helpful for defining the geological information contained in the seismic data. We propose a geological interpretation of seismic responses of various models in the frame of fluvio-deltaic deposits. The first model is the intermediate unit of the Mesa Verde outcrop, whose seismic response was computed by elastic wave modelling, after assignment of elastic parameters constant by lithofacies. The other models correspond to stochastic lithofacies simulations with different geostatistical characteristics. Their seismic responses were computed with 1D modelling (convolution). The geological interpretation carried out on those synthetic seismic data is based on a calibration of the seismic parameters in terms of probabilities of encountering the different lithofacies. The technique we use is a non parametric discriminant analysis. The seismic parameters are the amplitudes for the convolution models or impedances and reflection coefficients for the first model for which a post-stack stratigraphic inversion was carried out. We compare the seismic derived lithofacies to the true ones to determine the potential of the seismic data for describing the reservoir heterogeneities. We use the different models to discuss: the impact of the spatial distribution of heterogeneities on the geological interpretation of the seismic data; the influence of the seismic lateral filtering on the interpretation the influence of the number of wells, used in the interpretation, on the final results.
South Dakota Geological Survey
NSDL National Science Digital Library
The mission of the geological survey is to conduct geologic studies, hydrologic studies, and research, and to collect, correlate, preserve, interpret, and disseminate information, leading to a better understanding of the geology and hydrology of South Dakota. Information includes maps of relief, geology, ground water, and earthquakes; projects such as well testing, hydrology, and aquifers; and searchable databases, such as lithologic logs, digital base, and water quality. Links are provided for more information.
NSDL National Science Digital Library
The Louisiana Geological Survey, located at Louisiana State University, developed this website to promote its goal to provide geological and environmental data that will allow for environmentally sound natural resource development and economic decisions. Users can find general information about the Survey's mission, staff, plan, and history. The website features the research and publications of the Basin Research, Cartographic, Coastal, Geologic Mapping, and Water and Environmental sections. Researchers can discover stratigraphic charts of Louisiana, information on lignite resources, and other geologic data.
South Carolina Geological Survey
NSDL National Science Digital Library
The South Carolina Geological Survey (SCGS) homepage contains information about state mapping, education and outreach programs, and recent news. For educators, there is the Earth Science education series of publications which includes presentations and page-size graphics on such topics as earthquakes, plate tectonics, geologic time, fossils, and others. Other materials include information on mineral resources, links to organizations in and about South Carolina geology, the South Carolina core repository, the Geologic Map of South Carolina, and others.
NSDL National Science Digital Library
The Iowa Geological Survey Bureau (GSB) homepage contains: general information about the geology of Iowa; the Natural Resources Geographic Information System, which is a collection of databases on geology and water wells; and information about GSB staff, geologic studies, water monitoring programs, and services. There are maps, photographs, general interest articles, technical abstracts, lists of available publications, and an on-line book about the natural resource history of Iowa.
Predictive uncertainty analysis of plume distribution for geological carbon sequestration using sparse-grid Bayesian method
NASA Astrophysics Data System (ADS)
Shi, X.; Zhang, G.
Because of the extensive computational burden, parametric uncertainty analyses are rarely conducted for geological carbon sequestration (GCS) process based multi-phase models. The difficulty of predictive uncertainty analysis for the CO2 plume migration in realistic GCS models is not only due to the spatial distribution of the caprock and reservoir (i.e. heterogeneous model parameters), but also because the GCS optimization estimation problem has multiple local minima due to the complex nonlinear multi-phase (gas and aqueous), and multi-component (water, CO2, salt) transport equations. The geological model built by Doughty and Pruess (2004) for the Frio pilot site (Texas) was selected and assumed to represent the 'true' system, which was composed of seven different facies (geological units) distributed among 10 layers. We chose to calibrate the permeabilities of these facies. Pressure and gas saturation values from this true model were then extracted and used as observations for subsequent model calibration. Random noise was added to the observations to approximate realistic field conditions. Each simulation of the model lasts about 2 hours. In this study, we develop a new approach that improves computational efficiency of Bayesian inference by constructing a surrogate system based on an adaptive sparse-grid stochastic collocation method. This surrogate response surface global optimization algorithm is firstly used to calibrate the model parameters, then prediction uncertainty of the CO2 plume position is quantified due to the propagation from parametric uncertainty in the numerical experiments, which is also compared to the actual plume from the 'true' model. Results prove that the approach is computationally efficient for multi-modal optimization and prediction uncertainty quantification for computationally expensive simulation models. Both our inverse methodology and findings can be broadly applicable to GCS in heterogeneous storage formations.
Geological and production characteristics of strandplain/barrier island reservoirs in the United States
Cole, E.L.; Fowler, M.; Jackson, S.; Madden, M.P.; Reeves, T.K.; Salamy, S.P.; Young, M.A.
The Department of Energy`s (DOE`s) primary mission in the oil research program is to maximize the economically and environmentally sound recovery of oil from domestic reservoirs and to preserve access to this resource. The Oil Recovery Field Demonstration Program supports DOE`s mission through cost-shared demonstrations of improved Oil Recovery (IOR) processes and reservoir characterization methods. In the past 3 years, the DOE has issued Program Opportunity Notices (PONs) seeking cost-shared proposals for the three highest priority, geologically defined reservoir classes. The classes have been prioritized based on resource size and risk of abandonment. This document defines the geologic, reservoir, and production characteristics of the fourth reservoir class, strandplain/barrier islands. Knowledge of the geological factors and processes that control formation and preservation of reservoir deposits, external and internal reservoir heterogeneities, reservoir characterization methodology, and IOR process application can be used to increase production of the remaining oil-in-place (IOR) in Class 4 reservoirs. Knowledge of heterogeneities that inhibit or block fluid flow is particularly critical. Using the TORIS database of 330 of the largest strandplain/barrier island reservoirs and its predictive and economic models, the recovery potential which could result from future application of IOR technologies to Class 4 reservoirs was estimated to be between 1.0 and 4.3 billion barrels, depending on oil price and the level of technology advancement. The analysis indicated that this potential could be realized through (1) infill drilling alone and in combination with polymer flooding and profile modification, (2) chemical flooding (sufactant), and (3) thermal processes. Most of this future potential is in Texas, Oklahoma, and the Rocky Mountain region. Approximately two-thirds of the potentially recoverable resource is at risk of abandonment by the year 2000.
NSDL National Science Digital Library
If your research or interests lie in the geology of South Dakota, then the state's Geological Survey Program Web site is for you. Offered are online publications and maps, a geologic reference database, a lithologic logs database, digital base maps, a water quality database, and several other quality information sources worth checking out.
The heterogeneous reaction of particle-phase methyl esters and ozone elucidated by photoelectron resonance capture ionization: Direct products of ozonolysis and secondary reactions leading to the formation of ketones
James Zahardis; Brian W. LaFranchi; Giuseppe A. Petrucci
Photoelectron resonance capture ionization aerosol mass spectrometry (PERCI-AMS) facilitates the measurement of heterogeneous particle-gas phase reactions of relevance to atmospheric chemistry. This methodology, which has been demonstrated to have analytical merit for single component particles, such as oleic acid, has been extended to heterogeneous reactions of binary and ternary particle systems. Herein is described the direct measurement of unambiguous products
Fight or flight: plastic behavior under self-generated heterogeneity
TomᚠHerben; Ariel Novoplansky
Plants are able to plastically respond to their ubiquitously heterogeneous environments; however, little is known about the\\u000a conditions under which plants are expected to avoid or confront their neighbors in dense stands, where heterogeneity is self-generated\\u000a by non-uniform growth and feedback between plant interactions and stand heterogeneity. We studied the role of plasticity for\\u000a spatial pattern-formation and the resulting stand-level
Wave Propagation in Jointed Geologic Media
Antoun, T
Predictive modeling capabilities for wave propagation in a jointed geologic media remain a modern day scientific frontier. In part this is due to a lack of comprehensive understanding of the complex physical processes associated with the transient response of geologic material, and in part it is due to numerical challenges that prohibit accurate representation of the heterogeneities that influence the material response. Constitutive models whose properties are determined from laboratory experiments on intact samples have been shown to over-predict the free field environment in large scale field experiments. Current methodologies for deriving in situ properties from laboratory measured properties are based on empirical equations derived for static geomechanical applications involving loads of lower intensity and much longer durations than those encountered in applications of interest involving wave propagation. These methodologies are not validated for dynamic applications, and they do not account for anisotropic behavior stemming from direcitonal effects associated with the orientation of joint sets in realistic geologies. Recent advances in modeling capabilities coupled with modern high performance computing platforms enable physics-based simulations of jointed geologic media with unprecedented details, offering a prospect for significant advances in the state of the art. This report provides a brief overview of these modern computational approaches, discusses their advantages and limitations, and attempts to formulate an integrated framework leading to the development of predictive modeling capabilities for wave propagation in jointed and fractured geologic materials.
NSDL National Science Digital Library
The Arkansas Geological Survey (AGS) homepage aims to develop and provide knowledge of the geology and hydrogeology of the State, and to stimulate development and effective management and utilization of the mineral, fossil-fuel, and water resources of Arkansas while protecting the environment. The AGC collects and disperses geologic data consisting of geologic maps, historical data concerning resources, and various datasets concerning water, fossil-fuel, and mineral resources of Arkansas. The site contains publications that can be ordered, sections about Arkansas geology, a list of mineral producers of Arkansas, and reports on mineral resources.
NSDL National Science Digital Library
At virtual-geology.info, Roger Suthren, a professor at Oxford Brookes University, offers educational materials on geologic phenomena throughout the world. Users can take virtual field trips to study the geology of Scotland, Alaska, and France. In the Regional Geology link, visitors can view wonderful pictures of the volcanoes of Germany, Italy, France, and Greece. Educators can find images of sediments and sedimentary rocks which can be used in a variety of classroom exercises. The website supplies descriptions and additional educational links about sedimentology and environmental geology.
NSDL National Science Digital Library
This website contains geologic maps of Kentucky, with a discussion of geologic time in regards to the rocks, minerals, fossils, and economic deposits found there. There are also sections that describe strata and geologic structures beneath the surface (faults, basins, and arches), the structural processes (folding and faulting) that create stratigraphic units, the geomorphology of the state, geologic information by county, a general description of geologic time, fossil, rocks, and minerals of Kentucky, and a virtual field trip through Natural Bridges State Park. Links are provided for further information.
Abbreviations used in publications of the United States Geological Survey
U.S. Geological Survey
The use of abbreviations in publications of the Geological Survey is determined by several forces working in different directions. Pulling in the direction of greater condensation and the freer use of abbreviations and symbols is the desire to achieve greater economy in publications. Working in the opposite direction is the desire to have the publications used more conveniently by an increasingly heterogeneous public.
Maintenance of ventricular fibrillation in heterogeneous ventricle.
Arevalo, Hamenegild J; Trayanova, Natalia A
Although ventricular fibrillation (VF) is the prevalent cause of sudden cardiac death, the mechanisms that underlie VF remain elusive. One possible explanation is that VF is driven by a single robust rotor that is the source of wavefronts that break-up due to functional heterogeneities. Previous 2D computer simulations have proposed that a heterogeneity in background potassium current (IK1) can serve as the substrate for the formation of mother rotor activity. This study incorporates IK1 heterogeneity between the left and right ventricle in a realistic 3D rabbit ventricle model to examine its effects on the organization of VF. Computer simulations show that the IK1 heterogeneity contributes to the initiation and maintenance of VF by providing regions of different refractoriness which serves as sites of wave break and rotor formation. A single rotor that drives the fibrillatory activity in the ventricle is not found in this study. Instead, multiple sites of reentry are recorded throughout the ventricle. Calculation of dominant frequencies for each myocardial node yields no significant difference between the dominant frequency of the LV and the RV. The 3D computer simulations suggest that IK1 spatial heterogeneity alone can not lead to the formation of a stable rotor. PMID:17947061
NSDL National Science Digital Library
This is the homepage of the Ohio Geological Survey. Materials available through the site include a variety of publications, particularly the Survey's reports, bulletins, information circulars, guidebooks, and many others. There is an extensive selection of maps, including topographic maps in several scales, and downloadable geologic maps of several themes (drift thickness, bedrock geology, karst areas, glacial geology, and many others), as well as digital maps and data. The interactive maps section features online map viewers of abandoned mines, earthquake epicenters, surficial geology, geology of Lake Erie, and others. The educational resources page has links to the 'Hands On Earth' series of activities, GeoFacts (short bulletins on Ohio geological topics), nontechnical educational leaflets, field guides, and links to other publications, rock and mineral clubs, educational associations, and related websites. There is also a link to the Ohio Seismic Network, a network of seismograph stations located at colleges, universities, and other institutions that collects and disseminates information about earthquakes in Ohio.
A LONG, LONG time ago: geologic timescales
NSDL National Science Digital Library
Elizabeth Johnson
Each student randomly picks a card with a geologic event (written description and an image) on it. A timeline has 11 events, not including the formation of the Earth and today. Students attach their event where they think it should go on a 45.5' timeline (in the hallway) made out of paper adding tape and mark the location on the timeline. They return to the classroom and receive a list of age dates for each event. Each group figures out the scale (1 foot = 100 million years) and then moves their events to the correct locations. Students are asked how the position of the events changed, and answer other questions that reinforce the difference between human timescales and geologic timescales. The powerpoint file below contains a template for making geologic event labels for the index cards. Instructors can tailor the geologic event list to fit their course.
Forming Heterogeneous Groups for Intelligent Collaborative Learning Systems with Ant
of the unsuccessful outcomes of group work stem from the formation process (e.g., [14], [18]). Although group as well as the performance level to form heterogeneous groups. The research work has two main goalsForming Heterogeneous Groups for Intelligent Collaborative Learning Systems with Ant Colony
Heterogeneous Catalysis: On Bathroom Mirrors and Boiling Stones
ERIC Educational Resources Information Center
Philipse, Albert P.
Though heterogeneous nucleation of liquid droplets on a smooth surface (such as a bathroom mirror) is a classical topic in nucleation theory, it is not well-known that this topic is actually a pedagogical example of heterogeneous catalysis: the one and only effect of the surface is to lower the activation Gibbs energy of droplet formation. Inģ
Heterogeneous Chemistry Related to Stratospheric Aircraft
NASA Technical Reports Server (NTRS)
Tolbert, Margaret A.
Emissions from stratospheric aircraft that may directly or indirectly affect ozone include NO(y), H2O, soot and sulfuric acid. To fully assess the impact of such emissions, it is necessary to have a full understanding of both the homogeneous and heterogeneous transformations that may occur in the stratosphere. Heterogeneous reactions on stratospheric particles play a key role in partitioning ozone-destroying species between their active and reservoir forms. In particular, heterogeneous reactions tend to activate odd chlorine while deactivating odd nitrogen. Accurate modeling of the net atmospheric effects of stratospheric aircraft requires a thorough understanding of the competing effects of this activation/deactivation. In addition, a full understanding of the potential aircraft impacts requires that the abundance, composition and formation mechanisms of the particles themselves be established. Over the last three years with support from the High Speed Research Program, we have performed laboratory experiments to determine the chemical composition, formation mechanism, and reactivity of stratospheric aerosols.
Water Challenges for Geologic Carbon Capture and Sequestration
Robin L. Newmark; Samuel J. Friedmann; Susan A. Carroll
Carbon capture and sequestration (CCS) has been proposed as a means to dramatically reduce greenhouse gas emissions with the continued use of fossil fuels. For geologic sequestration, the carbon dioxide is captured from large point sources (e.g., power plants or other industrial sources), transported to the injection site and injected into deep geological formations for storage. This will produce new
Generalized Geologic Map of the Conterminous United States
NSDL National Science Digital Library
This site from the USGS features a geologic map of the United States using data prepared for publication in the National Atlas of the United States. There are explanations, documentations, and PDF files presenting the geologic map and a map unit chart, plus archives of ArcInfo files in several formats.
Geologic map of the Patagonia Mountains, Santa Cruz County, Arizona
Graybeal, Frederick T.; Moyer, Lorre A.; Vikre, Peter; Dunlap, Pamela; Wallis, John C.
Several spatial databases provide data for the geologic map of the Patagonia Mountains in Arizona. The data can be viewed and queried in ArcGIS 10, a geographic information system; a geologic map is also available in PDF format. All products are available online only.
The chapter discusses subsurface property rights as they apply to geologic sequestration (GS) of carbon dioxide (CO2). GS projects inject captured CO2 into deep (greater than ~1 km) geologic formations for the explicit purpose of avoiding atmospheric emission of CO2. Because of t...
The paper discusses subsurface property rights as they apply to geologic sequestration (GS) of carbon dioxide (CO2). GS projects inject captured CO2 into deep (greater than ~1 km) geologic formations for the explicit purpose of avoiding atmospheric emission of CO2. Because of the...
The paper discusses subsurface property rights as they apply to geologic sequestration (GS) of carbon dioxide (CO2). GS projects inject captured CO2 into deep (greater than ~1 km) geologic formations for the explicit purpose of avoiding atmospheric emission of CO2. Because of the...
Heterogeneous anchoring in dichotomous choice valuation framework
Paris-Sud XI, Universitķ de
Heterogeneous anchoring in dichotomous choice valuation framework by Emmanuel Flachaire Ces of anchoring in contingent valuation surveys that use the double-bounded elicitation format. Anchoring occurs when responses to the follow-up dichotomous choice valuation question are influenced by the bid
Endothelial Cell Heterogeneity
Aird, William C.
The endothelial lining of blood vessels shows remarkable heterogeneity in structure and function, in time and space, and in health and disease. An understanding of the molecular basis for phenotypic heterogeneity may provide important insights into vascular bed-specific therapies. First, we review the scope of endothelial heterogeneity and discuss its proximate and evolutionary mechanisms. Second, we apply these principles, together with their therapeutic implications, to a representative vascular bed in disease, namely, tumor endothelium. PMID:22315715
Structure, Thermodynamics and Kinetics of Chemically Heterogeneous Interfaces
Palafox Hernandez, Jesus Pablo
), and a metal alloy interface (Cu-Pb). In both systems, interfacial prefreezing (crystal formation above the melting point of the fluid) was observed and this prefreezing was seen to promote heterogeneous nucleation, when the systems were cooled below...
Geology Before Pluto: Pre-encounter Considerations
NASA Technical Reports Server (NTRS)
Moore, Jeffrey M.
Pluto, its large satellite Charon, and its four known satellites represent the first trans-Neptunian Kuiper Belt objects populating the outer-most solar system beyond the gas giant planets to be studied in detail from a spacecraft (New Horizons). A complete picture of the solar nebula, and solar system formation cannot be confidently formulated until representatives of this group of bodies at the edge of solar space have been examined. The Pluto system is composed of unique lunar- and intermediate-sized objects that can tell us much about how objects with volatile icy compositions evolve. Modeling of the interior suggests that geologic activity may have been to some degree, and observations of frost on the surface could imply the need for a geologic reservoir for the replenishment of these phases. However, the putative indicators of Pluto's geologic history are inconclusive and unspecific. Detailed examination of Pluto's geologic record is the only plausible means of bridging the gap between theory and observations. In this talk I will examine the potential importance of these tentative indications of geologic activity and how specific spacecraft observations have been designed and used to constrain the Pluto system's geologic history. The cameras of New Horizons will provide robust data sets that should be immanently amenable to geological analysis of the Pluto System's landscapes. In this talk, we begin with a brief discussion of the planned observations by New Horizons' cameras that will bear most directly on geological interpretability. Then I will broadly review major geological processes that could potentially operate of the surfaces of Pluto and its moons. I will first survey exogenic processes (i.e., those for which energy for surface modification is supplied externally to the planetary surface): impact cratering, sedimentary processes (including volatile migration) and the work of wind. I will conclude with an assessment of prospects for endogenic activity in the form of tectonics and cryo-volcanism.
Geology Before Pluto: Pre-encounter Considerations
NASA Astrophysics Data System (ADS)
Moore, J. M.
Pluto, its large satellite Charon, and its four small known satellites represent the first trans-Neptunian Kuiper Belt objects populating the outer-most solar system beyond the gas giant planets to be studied in detail from a spacecraft (New Horizons). A complete picture of the solar nebula and solar system formation cannot be confidently formulated until representatives of this group of bodies at the edge of solar space have been examined. The Pluto system is composed of unique, lunar- and intermediate-sized objects that can tell us much about how objects with volatile icy compositions evolve. Modeling of the interior suggests that geologic activity may have been significant to some degree, and observations of frost on the surface could imply the need for a geologic reservoir for the replenishment of these phases. However, these putative indicators of Pluto's geologic history are inconclusive and unspecific. Detailed examination of Pluto's geologic record is the only plausible means of bridging the gap between theory and observation. In this talk I will examine the potential importance of these tentative indications of geologic activity and how specific spacecraft observations have been designed and used to constrain the Pluto system's geologic history. The cameras of New Horizons will provide robust data sets that should be immanently amenable to geological analysis of the Pluto system's landscapes. In this talk, we begin with a brief discussion of the planned observations by the New Horizons cameras that will bear most directly on geological interpretability. Then I will broadly review major geological processes that could potentially operate on the surfaces of Pluto and its moons. I will first survey exogenic processes (i.e., those for which energy for surface modification is supplied externally to the planetary surface): impact cratering, sedimentary processes (including volatile migration), and the work of wind. I will conclude with an assessment of the prospects for endogenic activity in the form of tectonics and cryovolcanism.
Physical and geological processes of delta formationĀ
Bates, Charles Carpenter
(Jbc, lM55MW-4y 0T2-4-4y 28 24 Pi-20-M4 D21s0 Bhs0sMTM5My9^ 20 0gs n4-isT8-09 M6 SM.0gsT4 D25-6MT4-2 BEM8 P4ys5s8^ 241 0gs n4-isT8-09 M6 Dg-r2yMf gs yT21.20s1 W-0g 1-80-4r0-M4 241 W28 rMuu-88-M4s1 28 2 SsrM41 E-s.0s4240 -4 h29f t(J)7 P-T lMTrs 288-y4us... dYAP Dg2T5s8 D2TFs40sT R20s8 W28 oMT4 -4 G2TT-8M4f Y55-4M-8 M4 NMisuosT ttf t(taf Gs 200s41s1 Hs O2.W n4-isT8-09 -4 VTss4r2805sf Y41-242 28 2 Csr0MT SrgM52T 6TMu t()p 0M t()(m u2wMT-4y -4 ysM5My9, nFM4 Tsrs-i-4y W-0g 1-80-4r0-M4 0gs P, R, 1sy...
Physical and geological processes of delta formation
Bates, Charles Carpenter
g O200sT4 R28s1 M4 AgsMTs0-r25 DM4rsF08 M6 l5 MW 6TMu 24 L.05s0 -4 0gs OTs8 s 4rs M6 2 E-00MT25 D.TTs40, ttJ DGPOAIC d ? G?HCPnEYDS Ll SACIPh lELx YN PEEndYPE DGPNNIES NIPC AGI SIP cJf G91T2.5-r8 M6 l5 MW -4 S 5MF-4y N20.T25 Dg244s58 -4 P55.i...(Jbc, lM55MW-4y 0T2-4-4y 28 24 Pi-20-M4 D21s0 Bhs0sMTM5My9^ 20 0gs n 4-isT8-09 M6 SM.0gsT4 D25-6MT4-2 BEM8 P4ys5 s 8^ 241 0gs n 4-isT8-09 M6 Dg-r2yMf gs yT21.20s1 W-0g 1-80-4r0-M4 241 W28 rMuu-88-M4 s1 28 2 SsrM41 E-s.0s4240 -4 h29f t(J)7 P-T lMTrs 288-y4us...
12.001 Introduction to Geology, Spring 2011
Perron, Taylor
This course introduces students to the basics of geology. Through a combination of lectures, labs, and field observations, we will address topics ranging from formation of the elements, mineral and rock identification, and ...
4th Grade Geology Lesson Plans
NSDL National Science Digital Library
This site has a lesson plan for a class activity on mountain building and graben and horst formation. This particular lesson is number 14, at the top of the page. There are a few other geology lesson plans also listed on this site.
Connecting Soils and Glacial Geology
NSDL National Science Digital Library
Holly Dolliver
The goal of this activity is to provide students an opportunity to connect soil science to surficial geology by using a Soil Surveys. By the end of the activity, students should be able to use a Soil Survey to identify and interpret landforms and surficial features. This activity can be adapted to variety of process (ex. eolian deposits, glacial deposits, bedrock weathering, etc.). County-level soil surveys are available in both paper and online formats for the majority of the United States. Designed for a geomorphology course Has minimal/no quantitative component
Ore metals through geologic history.
Meyer, C
The ores of chromite, nickel, copper, and zinc show a wide distribution over geologic time, but those of iron, titanium, lead, uranium, gold, silver, molybdenum, tungsten, and tin are more restricted. Many of the limitations to specific time intervals are probably imposed by the evolving tectonic history of Earth interacting with the effects of the biomass on the evolution of the earth's s surface chemistry. Photosynthetic generation of free oxygen and "carbon" contributes significantlly to the diversity of redox potentials in both sedimentary and igneous-related processes of ore formation, influencing the selection of metals at the source, during transport, and at the site of ore deposition. PMID:17777763
Youash, Y.
The extremely large oil reserves in Kuwait result from the presence of all conditions necessary for hydrocarbon generation, migration, entrapment, and preservation, which can be ascribed to an exceptionally large trap volume in a simple geological setting and a late expulsion and migration from a huge area of thermally mature source rocks. The Lower and middle Cretaceous sequence of Kuwait is among the world's richest hydrocarbon habitats. The depositional history is dominated by sedimentation on a very stable broad platform characterized by quiescence as reflected by a continuous deposition in a slowly subsiding sea bottom. The reservoirs are composed of thick sandstone of the Wara, Burgan, and Zubar formations. In addition to these, Mauddud Limestone forms a good reservoir in the northern fields and, in the south, the oolitic limestone of the Lower Cretaceous in Greater Burgan, Umm Gudair, and Minagish fields contains substantial hydrocarbon deposits. The sandstone reservoirs are the world's largest over 1,500 ft (450 m) in thickness of perfect reservoir quality and composed of well-sorted, medium to coarse-grained sands that were deposited in a littoral or on the edge of a deltaic and coastal environment. The source rocks are mostly likely the same reservoir rocks, particularly with downdip more shaly development of widespread thermally mature organic rich facies juxataposed with a carbonate-sandstone shelf.
NSDL National Science Digital Library
Offered by the United States Geological Survey (USGS) as a general interest publication, this site is an online edition of a text by the same name, offering a concise overview of the concepts associated with the age of the Earth. The online edition was revised in October of 1997 to reflect current thinking on this topic. Section headers are Geologic Time, Relative Time Scale, Major Divisions of Geologic Time, Index Fossils, Radiometric Time Scale, and Age of the Earth.
NSDL National Science Digital Library
From the College of William of Mary Department of Geology comes the Geology of Virginia Web site. From the Appalachian Plateau to the coastal plain, visitors can explore the geology and physical characteristics of the diverse landscape of the commonwealth of Virginia through simple descriptions and well designed graphics. Even if you don't live in the area, the site does a good job of capturing the interest of anyone looking for quality material on the presented subjects.
NSDL National Science Digital Library
Allen Glazner
These images of geologic phenomena are used to supplement introductory geology classes at the University of North Carolina at Chapel Hill. The images are categorized under plutonic, volcanic and sedimentary rocks; structural geology; weathering; and coastlines. There are photographs of different kinds of volcanoes; lavas and pyroclastic rocks; volcanic hazards; different types of sedimentary rocks and sedimentary structures; folds and faults; beach processes; and barrier islands.
Sedimentology and petroleum geology
Bjorlykke, K.O. (Oslo Univ. (Norway))
This book presents an introduction to sedimentology as well as petroleum geology. It integrates both subjects, which are closely related but mostly treated separately. The author covers the basic aspects of sedimentology, sedimentary geochemistry and diagenesis. Principles of stratigraphy, seismic stratigraphy and basin modelling forms the base for the part on petroleum geology. Subjects discussed include the composition of kerogen and hydrocarbons, theories of migration and trapping of hydrocarbons and properties of reservoir rocks. Introductions to well logging and production geology are given.
Final Technical Report - Investigation into the Relationship between Heterogeneity and Heavy-Tailed Solute Transport
Weissmann, Gary S
The objective of this project was to characterize the influence that naturally complex geologic media has on anomalous dispersion and to determine if the nature of dispersion can be estimated from the underlying heterogeneous media. The UNM portion of this project was to provide detailed representations of aquifer heterogeneity through producing highly-resolved models of outcrop analogs to aquifer materials. This project combined outcrop-scale heterogeneity characterization (conducted at the University of New Mexico), laboratory experiments (conducted at Sandia National Laboratory), and numerical simulations (conducted at Sandia National Laboratory and Colorado School of Mines). The study was designed to test whether established dispersion theory accurately predicts the behavior of solute transport through heterogeneous media and to investigate the relationship between heterogeneity and the parameters that populate these models. The dispersion theory tested by this work was based upon the fractional advection-dispersion equation (fADE) model. Unlike most dispersion studies that develop a solute transport model by fitting the solute transport breakthrough curve, this project explored the nature of the heterogeneous media to better understand the connection between the model parameters and the aquifer heterogeneity. We also evaluated methods for simulating the heterogeneity to see whether these approaches (e.g., geostatistical) could reasonably replicate realistic heterogeneity. The UNM portion of this study focused on capturing realistic geologic heterogeneity of aquifer analogs using advanced outcrop mapping methods.
Geologic input to enhanced oil recovery project planning in south Oman
Watts, N.L.; Ellis, D.; Heward, A.P.; Maier, G.; Marks, G.P.
South Oman clastic reservoirs contain a combined stock-tank oil in place of more than 1.9 billion m/sup 3/ of predominantly heavy oil distributed in almost 40 fields of varying size. Successful early application of such enhanced oil recovery (EOR) methods as steam flood, polymer drive, and steam soak could realize undiscounted incremental recoveries of 244 million m/sup 3/ of oil. Target oil is contained in three reservoir intervals with distinct characteristics relevant to EOR. (1) The Cambrian-Ordovician Haima Group is a thick monotonous sequence of continental and coastal sands; major problems are steam-rock reactions, recovery factors, effective kv/kh (ratio of vertical to horizontal permeability), and aquifer strength. (2) The Permian-Carboniferous Al Khlata Formation is a glacial package showing severe heterogeneity, strong permeability anisotropy, and poor predictability. (3) The Permian Gharif Formation is a coastal to fluvial sequence with isolated and multilayer channel sands, smectitic clays, and anomalous primary production performance. Several EOR pilot projects are either ongoing or in preparation as part of a longer term EOR strategy. Geologic input is important at four essential stages of pilot planning: initial project ranking, optimization of pilot location, definition of pilot size, and predictive/history match simulations. Each stage is illustrated using a specific project example from south Oman to show the diverse geologic and logistic problems of the area. Although geologic aspects are highlighted, EOR project planning in south Oman is multidisciplinary, with integration being aided by a dedicated EOR coordination department.
NSDL National Science Digital Library
Cara Burberry
This is an exercise in which students are reintroduced to geologic maps and encouraged to "deconstruct" the map into constituent elements in order to understand the geologic history of the area. The preceding lectures in the course have recapitulated material that the students have covered in Introduction to Physical Geology. During class, the students work through the maps that were part of lab exercises in the Intro level course, so that basic concepts are recalled (superposition, cross-cutting relationships, basic faults and folds). The final product is a geologic history of this map area.
NSDL National Science Digital Library
Andrew Smith
This exercise is designed to simulate how a basic geological investigation of a site takes place. A basic geological investigation includes familiarizing yourself with the unconsolidated sediments, rocks, structural geology, and groundwater present at your site. As part of this exercise you will have to properly identify a variety of rock types and sediments, create maps that represent data you collected at each location, and complete a basic report of your findings (optional). Once completed, this exercise should give students a basic understanding of how the various concepts used throughout the semester are applied in the real world in the form of a geological investigation.
Heterogeneous Semantics in Ptolemy
California at Irvine, University of
Modeling Heterogeneous Semantics in Ptolemy with Modular Actor Interfaces Chris Shaver working analyses and forms of verification that cross the boundaries of heterogeneous composition. #12;Ptolemy II be understood in clear mathematical terms. From "A Modular Formal Semantics for Ptolemy", Tripakis et al
Hydrogeochemical modeling of a thermal system and lessons learned for CO 2 geologic storage
L. F. Auquķ; P. Acero; M. J. Gimeno; J. B. G¾mez; M. P. Asta
Geological storage of carbon dioxide is presently considered to be one of the main strategies to mitigate the impact of the emissions of this gas on global warming. Among the various alternatives considered for CO2 geological storage, one of the main geological candidates for hosting injected CO2 in the long term are deep porous reservoir rock formations saturated with brackish
Nievita F. Bueno Watts; Steven Semken; Monica Pineda; Cheryl Alvarado
When observing the natural landscape at National Parks, how do visitors make meaning of the geology? Interpretative geologic displays and programs here are typically uninformed by knowledge of visitor conceptions. Visitors' ideas about geological processes and landscape formation at Petrified Forest National Park in Arizona were investigated by interviewing 80 visitor groups (N= 235) at a landscape overlook and analyzing
NSDL National Science Digital Library
First, researchers at the University of California, San Diego discuss the importance of studying earthquakes on the moon, also known as moonquakes, and the Apollo Lunar Seismic Experiment (1). Users can discover the problems scientists must deal with when collecting the moon's seismic data. The students at Case Western Reserve University created the second website to address three missions the Institute of Space and Astronautical Science (ISAS) has planned between now and 2010, including a mission to the moon (2). Visitors can learn about the Lunar-A probe that will be used to photograph the surface of the moon, "monitor moonquakes, measure temperature, and study the internal structure." Next, the Planetary Data Service (PDS) at the USGS offers users four datasets that they can use to create an image of a chosen area of the moon (3). Each dataset can be viewed as a basic clickable map; a clickable map where users can specify size, resolution, and projection; or an advanced version where visitors can select areas by center latitude and longitude. The fourth site, produced by Robert Wickman at the University of North Dakota, presents a map of the volcanoes on the moon and compares their characteristics with those on earth (4). Students can learn how the gravitational forces on the Moon affect the lava flows. Next, Professor Jeff Ryan at the University of South Florida at Tampa supplies fantastic images and descriptive text of the lunar rocks obtained by the Apollo missions (5). Visitors can find links to images of meteorites, terrestrial rocks, and Apollo landings as well. At the Science Channel website, students and educators can find a video clip discussing the geologic studies on the moon along with videos about planets (6). Users can learn about how studying moon rocks help scientists better understand the formation of the earth. Next, the Smithsonian National Air and Space Museum presents its research of "lunar topography, cratering and impacts basins, tectonics, lava flows, and regolith properties" (7). Visitors can find summaries of the characteristics of the moon and the main findings since the 1950s. Lastly, the USGS Astrogeology Research Program provides archived lunar images and data collected between 1965 and 1992 by Apollo, Lunar Orbiter, Galileo, and Zond 8 missions (8). While the data is a little old, students and educators can still find valuable materials about the moon's topography, chemical composition, and geology.
Comprehensive geological history of asteroid Vesta
NASA Astrophysics Data System (ADS)
Marchi, S.; Williams, D. A.; McSween, H. Y.; Jaumann, R.; Raymond, C. A.; Russell, C. T.
In this paper, we present a time-stratigraphic scheme and geologic time scale for the asteroid Vesta, based on global geologic mapping and other analyses of NASA Dawn spacecraft data, supplemented with insights gained from laboratory studies of howardite-eucrite-diogenite (HED) meteorites and geophysical modeling. We identify four geologic time periods for Vesta, associated with the formation of major impacts: Pre-Veneneian, Veneneian, Rheasilvian, and Marcian. The Pre-Veneneian period covers the time from the formation of Vesta (a few Myr after the formation of the first solids in the proto-solar disk that took place at ś4.57 Gyr ago) up to the Veneneia impact event. The Veneneian period covers the time between the Veneneia and Rheasilvia impact events. The Rheasilvian period covers the time between the formation of Rheasilvia and Marcia craters, and the Marcian period covers the time between the formation of Marcia crater until the present. Absolute ages for the boundaries of these periods have been derived by applying two crater chronologies, one based on the current understanding on asteroidal impact rate at Vesta and its evolution over time; the other is based on an extrapolated version of the lunar crater chronology. While the ages and durations of the various periods change considerably depending on which chronology is applied, the relative age of the Veneneia and Rheasilvia impacts is unambiguously determined by superposition relationships, while the formation of the Marcia crater clearly represents the youngest major geologic event on Vesta. Absolute model ages allow us to relate Vesta geologic time periods to key features of the main asteroid belt, such as the formation of the large vestan dynamical family. The formation ages of the Vesta's family can be assessed with independent means, such as by measuring the spreading of the family members in orbital space, and therefore provide a benchmark for both theoretical models of asteroid family evolution and crater chronology. Absolute ages also provide an important framework to interpret impact-generated radiometric ages of HEDs. Our proposed four-period geologic time scale for Vesta is consistent with those developed for other terrestrial bodies, such as the Moon, Mars, Earth, and Mercury, and allow us to place Vesta in the context of major phases of the evolution of the solar system, such as the Late Heavy Bombardment, a period of intense bombardment in the inner solar system triggered by the migration of the giant planets.
Structural geology of the Earth's exterior*
Burchfiel, B. C.
Plate tectonics offers an explanation for the present motions and heterogeneity of the rocks that form the external part of the Earth. It explains the origin of the first-order heterogeneity of oceanic and continental lithospheres. Furthermore, it explains the youth and simplicity of the oceanic lithosphere and offers the potential to explain the antiquity, complexity, and evolution of the continental lithosphere. The framework of plate tectonics must be used carefully, because there are geological features within continents, particularly in the more ancient rocks, that may require alternative explanations. The task of understanding lithospheric motions through geologic time must be focused on the continents, where the major evidence for 95% of Earth history resides. In interpreting earth motions from the geologic record, three needs seem paramount: (i) to develop a three-dimensional understanding of the kinematics, dynamics, and thermal structure of modern plate boundary systems and at the same time to recognize those geological and geophysical features that are unrelated to plate interaction; (ii) to use this understanding to reconstruct the extent and evolution of ancient systems that form the major elements of continental crust; and (iii) to determine the dynamics and evolution of systems that have no modern analogs. Decoupling along subhorizontal zones within the lithosphere may be widespread in all types of plate boundary systems. Thus, in order to interpret the motion and dynamics of the mantle correctly, it is important to know if upper lithospheric motion within boundary systems is controlled directly or indirectly by or is independent of deeper mantle motions. PMID:16592704
NASA Technical Reports Server (NTRS)
Woronow, A. (editor)
This second issue in a new series intended to serve the planetary geology community with a form for quick and thorough communications includes (1) a catalog of terrestrial craterform structures for northern Europe; (2) abstracts of results of the Planetary Geology Program, and (3) a list of the photographic holdings of regional planetary image facilities.
P. F. Burollet; A. B. Ferjami; F. Mejri
Recent discoveries and important oil shows have proven the existence of hydrocarbons in newly identified depocenters and reservoirs. In general, except for some areas around the producing fields, Tunisia is largely underdrilled. The national company ETAP has decided to release data and to publish a synthesis on the petroleum geology of Tunisia. The geology of Tunisia provides a fine example
External Resource: Geologic Time
NSDL National Science Digital Library
This NASA sponsored webpage, Center for Educational Technologies, teaches students about Geologic Time. The age of Earth is so long compared to all periods of time that we humans are familiar with, it has been given a special name: Geologic time. The age
U.S. Geological Survey
This bookmark, designed for use with U.S. Geological Survey activities at the 2nd USA Science and Engineering Festival (April 26¢29, 2012), is adapted from the more detailed Fact Sheet 2010¢3059 "Divisions of Geologic Time." The information that it presents is widely sought by educators and students.
ERIC Educational Resources Information Center
Dillon, William P.; And Others
Describes some of the geologic characteristics of the Caribbean region. Discusses the use of some new techniques, including broad-range swath imaging of the sea floor that produces photograph-like images, and satellite measurement of crustal movements, which may help to explain the complex geology of the region. (TW)
California Geological Survey - Landslides
NSDL National Science Digital Library
California Geological Survey
This page from the CA Geological Survey (CGS) presents information on landslides as well as maps and products of various past and present CGS programs to map and respond to landslides in the state of California, including the Forest and Watershed Geology Program, the Seismic Hazards Zonation Program, the Caltrans Highway Corridor Mapping project, and the Landslide Map Index.
Kurapov, Alexander
Earth Sciences with Geology Option Geological sciences focus on understanding the Earth, from its, mountain building, land surface evolution, and mineral resource creation over the Earth's 4.6 billion-year history. A geologist contributes to society through the discovery of earth resources, such as metals
NSDL National Science Digital Library
John Wagner
This classroom activity uses a cake to demonstrate geologic processes and introduce geologic terms. Students will learn how folds and faults occur, recognize the difference in behavior between brittle and ductile rocks, and attempt to predict structures likely to result from application of various forces to layered rocks. They will also attempt to interpret 'core samples' to determine subsurface rock structure.
NSDL National Science Digital Library
David Ozsvath
In this activity, students investigate the relationship between intensity of ground motion and type of rock or alluvium, as seen in the 1994 Northridge, California earthquake. They will examine a map of Mercalli intensity, a cross-section showing geologic structures and rock types, and a map of surficial geology, and answer questions pertaining to amplification of ground motion and S-wave velocities.
Bates, R.L.; Jackson, J.A.
This third edition of the Glossary of Geology contains approximately 37,000 terms, or 1,000 more than the second edition. New entries are especially numerous in the fields of carbonate sedimentology, hydrogeology, marine geology, mineralogy, ore deposits, plate tectonics, snow and ice, and stratigraphic nomenclature. Many of the definitions provide background information.
British Geological Survey: Learning
NSDL National Science Digital Library
The British Geological Survey (BGS) has a wealth of information about the earth sciences, and they are quite willing to share it with others. This page contains information and resources for anyone interested in geology for educational or leisure purposes, and it is contained with four sections. First up is "Popular geology", which includes "Britain beneath our feet", an interactive atlas of geology, resources, and land quality. This section also contains graphics about climate change and earthquakes. The second section is titled "Educational resources". Here visitors can ask scientists at the BGS specific questions and they can also download several free posters. The third section is called "Educational news and events" and it features upcoming events at the BGS and links to their free magazine, "Earthwise". The site is rounded out by the fourth section titled "From the BGS Archives". Here visitors can view historic geological photographs and also view field sketches and watercolors by Alexander Henry Green, the celebrated Victorian geologist.
Wyoming State Geological Survey
NSDL National Science Digital Library
This agency's mission is to study, examine, and seek an understanding of the geology, mineral resources, and physical features of the State; to prepare, publish, and distribute reports and maps of Wyoming's geology, mineral resources, and physical features; and to provide information, advice, and services related to the geology, mineral resources, and physical features of the State. This site contains details and reports about metals in Wyoming, earthquakes and other hazards, coal, industrial minerals, uranium, oil and gas. The field trip section contains details about various areas to visit with students and gives a general geologic description. There is also a searchable bibliography with publications about Wyoming geology. Links are provided for additional resources.
NSDL National Science Digital Library
This selection of slide shows provides a photographic tour of Maine geology. Users can choose slide shows on surficial, bedrock, and coastal geology; fossils, geologic hazards, groundwater and wells; or mineral collecting, mining, and quarrying.
Essential Elements of Geologic Reports.
ERIC Educational Resources Information Center
Webb, Elmer James
Described is a report outline for geologic reports. Essential elements include title; abstract; introduction; stratigraphy; petrography; geochemistry; petrology; geophysics; structural geology; geologic history; modeling; economics; conclusions; and recommendations. (Author/CW)
Roadside Geology of Yosemite Valley
NSDL National Science Digital Library
A virtual geology field trip to Yosemite Valley. Includes a geologic map of Yosemite, numerous large pictures of the area and discussion of geological events and natural disasters which have occurred in Yosemite.
Preliminary geologic mapping of Arsia Mons, Mars
NASA Technical Reports Server (NTRS)
Zimbelman, James R.
Geologic mapping of the Tharsis Montes at a scale of 1:500,000 was recently initiated as part of the Mars Geologic Mapping Program of NASA. Detailed mapping of the three large shield volcanoes and their surroundings will help to clarify the sequence of events which led to the formation of these features, as well as provide a basis for comparing the complex histories of the three related yet distinctive volcanic centers. Preliminary mapping of Arsia Mons at a scale of 1:2 M was carried out in preparation for detailed mapping. A map is presented along with a discussion of its contents.
Geologic map of Chickasaw National Recreation Area, Murray County, Oklahoma
Blome, Charles D.; Lidke, David J.; Wahl, Ronald R.; Golab, James A.
This 1:24,000-scale geologic map is a compilation of previous geologic maps and new geologic mapping of areas in and around Chickasaw National Recreation Area. The geologic map includes revisions of numerous unit contacts and faults and a number of previously ōundifferentiatedö rock units were subdivided in some areas. Numerous circular-shaped hills in and around Chickasaw National Recreation Area are probably the result of karst-related collapse and may represent the erosional remnants of large, exhumed sinkholes. Geospatial registration of existing, smaller scale (1:72,000- and 1:100,000-scale) geologic maps of the area and construction of an accurate Geographic Information System (GIS) database preceded 2 years of fieldwork wherein previously mapped geology (unit contacts and faults) was verified and new geologic mapping was carried out. The geologic map of Chickasaw National Recreation Area and this pamphlet include information pertaining to how the geologic units and structural features in the map area relate to the formation of the northern Arbuckle Mountains and its Arbuckle-Simpson aquifer. The development of an accurate geospatial GIS database and the use of a handheld computer in the field greatly increased both the accuracy and efficiency in producing the 1:24,000-scale geologic map.
Radionuclide migration in clayrock host formations for deep geological disposal of radioactive waste: advances in process understanding and up-scaling methods resulting from the EC integrated project `Funmig
NASA Astrophysics Data System (ADS)
Altmann, S.; Tournassat, C.; Goutelard, F.; Parneix, J. C.; Gimmi, T.; Maes, N.
One of the æpillars' supporting Safety Cases for deep geological disposal of radioactive waste in clayrock formations is the knowledge base regarding radionuclide (Rn) retention by sorption and diffusion-driven transport which is why the EC integrated project æFunmig' focused a major part of its effort on advancing understanding of these two macroscopic phenomena. This talk presents some of the main results of this four year effort (2005-2008). One of the keys to understanding diffusion-driven transport of anionic and cationic radionuclide species in clayrocks lies in a detailed understanding of the phenomena governing Rn total concentration and speciation (dissolved, adsorbed) in the different types of pore spaces present in highly-compacted masses of permanently charged clay minerals. Work carried out on a specifically synthesized montmorillonite (a model for the clay mineral fraction in clayrocks) led to development, and preliminary experimental validation, of a conceptually coherent set of theoretical models (molecular dynamics, electrostatic double layer, thermodynamic) describing dissolved ion and water solvent behavior in this material. This work, complemented by the existing state of the art, provides a sound theoretical basis for explaining such important phenomena as anion exclusion, cation exchange and the diffusion behavior of anions, weakly sorbing cations and water tracers. Concerning the behavior of strongly sorbing and/or redox-reactive radionuclides in clay systems, project research improved understanding of the nature of sorption reactions and sorbed species structure for key radioelements, or analogues (U, Se, Eu, Sm, Yb, Nd) on the basal surfaces and in the interlayers of synthetic or purified clay minerals. A probable mechanism for Se(IV) retention by reduction to Se░ in Fe2+-containing clays was brought to light; this same process was also studied on the Callovo-Oxfordien clayrock targeted by the French radwaste management program. The migration of most radionuclides in clayrocks, in particular the actinides, is limited by their strong sorption on rock mineral surfaces. Much effort was devoted in Funmig to improving understanding of this process on the clayrocks being studied in the Swiss, Belgian and French radwaste management programs. Specific attention was focused on (i) elucidating the effect of dissolved organic matter on Am(III), Th(IV), Eu(III) sorption on clayrock surfaces and (ii) determining the link between Kd measured on dispersed rock systems and the Kd operant in intact rock volumes, i.e. during diffusion. Regarding the latter question, results indicate that Kd values for ædispersed' and æintact' materials are quite similar for certain elements (Na, Sr, Cs, Co). On the other hand, Kd values obtained by modeling results of diffusion experiments involving strongly sorbing elements as Cs, Co and Eu were always significantly smaller than those predicted based on sorption data measured in corresponding batch systems. This is an area where additional research is being planned. A major effort was devoted to improving understanding of the effects of small-scale (?m to cm) clayrock structure and large-scale (dm to hm) mineralogical composition on radionuclide diffusion-retention. The program focusing on the small-scale produced a method for simulating the results of tracer diffusion in an intact rock based on the actual rock microstructure of the rock sample to be used in the diffusion experiment. This model was used to predict / inverse model the spatial distribution of highly sorbing tracers (Eu, Cu). This overall approach is also being used to understand how changes in mineralogical composition can affect the values of macroscopic diffusion parameters (De, tortuosity, anisiotropy). At a much larger scale, the results of (i) a geostatistical analysis of clayrock mineralogical variability and (ii) measurements of De and Kd dependence on mineralogy for Cs and Cl, were combined to create models of parameter variability at the formation scale. These models were used to evaluate t
A bibliography of planetary geology principal investigators and their associates, 1976-1978
NASA Technical Reports Server (NTRS)
This bibliography cites publications submitted by 484 principal investigators and their associates who were supported through NASA's Office of Space Sciences Planetary Geology Program. Subject classifications include: solar system formation, comets, and asteroids; planetary satellites, planetary interiors, geological and geochemical constraints on planetary evolution; impact crater studies, volcanism, eolian studies, fluvian studies, Mars geological mapping; Mercury geological mapping; planetary cartography; and instrument development and techniques. An author/editor index is provided.
Geologic map of the Dillon 1 degree by 2 degrees Quadrangle, Idaho and Montana
Ruppel, E.T.; Lopez, D.A.; O'Neill, J. M.
The digital ARC/INFO databases included in this website provide a GIS database for the geologic map of the Dillon 1 degree by 2 degree quadrangle of southwest Montana and east-central Idaho. The geologic map was originally published as U.S. Geological Survey Miscellaneous Investigations Series Map I-1803-H. This website directory contains ARC/INFO format files that can be used to query or display the geology of USGS Map I-1803-H with GIS software.
Development Plus Kinetic and Mechanistic Studies of a Prototype Supported-Nanoparticle Heterogeneous Catalyst Formation System in Contact with Solution: Ir(1,5-COD)Cl/ -Al2O3 and Its Reduction by H2 to Ir(0)n/?-Al2O3
Mondloch, J.; Wang, Q; Frenkel, A; Finke, R
An important question and hence goal in catalysis is how best to transfer the synthetic and mechanistic insights gained from the modern revolution in nanoparticle synthesis, characterization, and catalysis to prepare the next generation of improved, supported-nanoparticle heterogeneous catalysts. It is precisely this question and to-date somewhat elusive goal which are addressed by the present work. More specifically, the global hypothesis investigated herein is that the use of speciation-controlled, well-characterized, solid oxide supported-organometallic precatalysts in contact with solution will lead to the next generation of better composition, size- and shape-controlled, as well as highly active and reproducible, supported-nanoparticle heterogeneous catalysts-ones that can also be understood kinetically and mechanistically. Developed herein are eight criteria defining a prototype system for supported-nanoparticle heterogeneous catalyst formation in contact with solution. The initial prototype system explored is the precatalyst, Ir(1,5-COD)Cl/{gamma}-Al{sub 2}O{sub 3} (characterized via ICP, CO adsorption, IR, and XAFS spectroscopies), and the well-defined product, Ir(0){sub n}/{gamma}-Al{sub 2}O{sub 3} (characterized by reaction stoichiometry, TEM, and XAFS). The Ir(0){sub n}/{gamma}-Al{sub 2}O{sub 3} system proved to be a highly active and long-lived catalyst in the simple test reaction of cyclohexene hydrogenation and in comparison to two literature Ir(0){sub n}/Al{sub 2}O{sub 3} heterogeneous catalysts examined under identical conditions. High activity (2.2-4.8-fold higher than that of the literature Ir(0){sub n}/Al{sub 2}O{sub 3} catalysts tested under the same conditions) and good lifetime ({ge} 220,000 total turnovers of cyclohexene hydrogenation) are observed, in part by design since only acetone solvent, cyclohexene, and H{sub 2} are possible ligands in the resultant 'weakly ligated/labile-ligand' supported nanoclusters. Significantly, the Ir(1,5-COD)Cl/{gamma}-Al{sub 2}O{sub 3} + H{sub 2} {yields} Ir(0){sub n}/{gamma}-Al{sub 2}O{sub 3} heterogeneous catalyst formation kinetics were also successfully monitored using the cyclohexene hydrogenation reporter reaction method previously developed and applied to solution-nanoparticle formation. The observed sigmoidal supported-nanoparticle heterogeneous catalyst formation kinetics, starting from the Ir(1,5-COD)Cl/{gamma}-Al{sub 2}O{sub 3} precatalyst, are closely fit by the two-step mechanism of slow continuous nucleation (A {yields} B, rate constant k{sub 1} = 1.5(1.1) x 10{sup -3} h{sup -1}) followed by fast autocatalytic surface growth (A + B {yields} 2B, rate constant k{sub 2} = 1.6(2) x 10{sup 4} h{sup -1} M{sup -1}), where A is the Ir(1,5-COD)Cl/{gamma}-Al{sub 2}O{sub 3} precatalyst and B is the resultant Ir(0){sub n}/{gamma}-Al{sub 2}O{sub 3} catalyst. The kinetics are significant in establishing the ability to monitor the formation of supported-nanoparticle heterogeneous catalysts in contact with solution. They also suggest that the nine synthetic and mechanistic insights from the two-step mechanism of nanoparticle formation in solution should now apply also to the formation of supported-nanoparticle heterogeneous catalysts in contact with solution. The results open the door for new syntheses of supported-nanoparticle heterogeneous catalysts under nontraditional, mild, and flexible conditions where supported organometallics and other precursors are in contact with solution, so that additional variables such as the solvent choice, added ligands, solution temperature, and so on can be used to control the catalyst formation steps and, ideally, the resultant supported-nanoparticle heterogeneous catalyst composition, size, and shape.
Filtered density functions for solutes transported in heterogeneous aquifers
NASA Astrophysics Data System (ADS)
Sch³ler, Lennart; Suciu, Nicolae; Attinger, Sabine; Knabner, Peter
Geological formations are heterogeneous. Their properties are usually not measurable everywhere but only at some locations. This lack of knowledge implies uncertainty in aquifer parameters like hydraulic conductivity. As a consequence, transport of solutes through these formations is also uncertain and has to be described in a probabilistic sense. Mean and variance estimates of solute concentrations give some information on the probability distribution of concentrations. We present analytical results for the concentration variance in lowest order perturbation theory. Going beyond mean and variance estimates, we are able to state the transport equation for the whole probability density distribution of the concentration by adopting an approach first introduced in turbulence theory by Colucci et al. (1998), Phys. Fluids. However, we propose an alternative closure strategy and compare resulting effects on the probability density distribution. One prominent result is the temporal behavior of the solute concentration variance and its increase with distance from the injection point or with travel time. The generation of variance is balanced in the long time limit by a term that eliminates concentration variance. This balance indicates that the solute concentration is well described by its mean in the ergodic limit. In other words, only in the very long time limit the mean concentration is a good descriptor for the concentration. Hence, it is not sufficient to only use the mean to accurately describe the transport of a solute for earlier times. We propose to make use of spatial filtering and filtered density functions (FDF) to avoid these errors for finite times. The FDF evolution equations are similar in form with those of probability density functions, but their solutions are still random and depend on the width of the spatial filter. The filter is adjusted in order to minimize the produced concentration variance and thus the error introduced by averaging is minimized too.
Production Data Integration into High Resolution Geologic Models with Trajectory-based Methods and A Dual Scale Approach
Kim, Jong Uk
the essential features of the geologic model. To begin with, we sequentially coarsen the fine-scale geological model by grouping layers in such a way that the heterogeneity measure of an appropriately defined 'static' property is minimized within the layers...
Heterogeneity induces emergent functional networks for synchronization
NASA Astrophysics Data System (ADS)
Scafuti, Francesco; Aoki, Takaaki; di Bernardo, Mario
We study the evolution of heterogeneous networks of oscillators subject to a state-dependent interconnection rule. We find that heterogeneity in the node dynamics is key in organizing the architecture of the functional emerging networks. We demonstrate that increasing heterogeneity among the nodes in state-dependent networks of phase oscillators causes a differentiation in the activation probabilities of the links when a distributed local network adaptation strategy is used in an evolutionary manner. This, in turn, yields the formation of hubs associated to nodes with larger distances from the average frequency of the ensemble. Our generic local evolutionary strategy can be used to solve a wide range of synchronization and control problems.
Phenotypically heterogeneous populations in spatially heterogeneous environments.
Patra, Pintu; Klumpp, Stefan
The spatial expansion of a population in a nonuniform environment may benefit from phenotypic heterogeneity with interconverting subpopulations using different survival strategies. We analyze the crossing of an antibiotic-containing environment by a bacterial population consisting of rapidly growing normal cells and slow-growing, but antibiotic-tolerant persister cells. The dynamics of crossing is characterized by mean first arrival times and is found to be surprisingly complex. It displays three distinct regimes with different scaling behavior that can be understood based on an analytical approximation. Our results suggest that a phenotypically heterogeneous population has a fitness advantage in nonuniform environments and can spread more rapidly than a homogeneous population. PMID:24730780
Evidence of influence of regional and local heterogeneities within a chalk karst aquifer based on nitrates and chlorides analysis
NASA Astrophysics Data System (ADS)
El Janyani, S.; Dupont, J. P.; Massei, N.; D÷rfliger, N.
In Upper Normandy, a region located in the western Paris Basin, the main source of drinking water comes from the karst aquifer. Developing under the chalk plateaus, it is a covered aquifer overlaid by superficial formations of clay-with-flints and loess. Clay-with-flints result from chalk weathering whereas loess are wind periglacial deposits. The local geologic and hydrogelogic contexts are characterized by a mature development of sinkholes. The chalk karst is causing turbidity, often linked to the fast infiltration of surface water, carrying the products of river and slope erosion and associated contaminants into the aquifer through the sinkholes. Several authors have shown the potential of turbidity as a marker of suspended elements transport and karst conduits fast transport. In this study, we conducted monthly monitoring of 11 boreholes located in the upstream watershed near boreholes (surveyed by the French Geological Survey BRGM): Graveron-Semerville in the Southern department of Upper Normandy (Eure) and Rocquemont in the Norhtern department of Upper Normandy (Seine-Maritime). The monitoring carried out included water level and electrical conductivity (reflecting total water mineralization) measurements, and major elements analysis. In any case, the water levels are similar over time (in accordance with the reference borehole). High mineralizations are observed in the Eure boreholes with significant anomalies of nitrate (70 to 130 mg/l ) and chloride (35 to 90 mg/l). For the Seine Maritime boreholes, no anomalies in nitrates and chlorides were found. To explain such differences, the agricultural activities are not sufficiently different from the study site. The explanation would then come from different reservoirs involved in water storage: loessic formations, thicker and more spreaded in the Seine Maritime department and clay with flints, of significantly higher thickness on average in the Eure department. We also discuss the influence of the drainage network (input karst more or less connected to output karst) on the water ressource heterogeneity, including storage of contaminants (nitrates and chlorides) within the saturated zone of the chalk aquifer. This demonstrates two scales of heterogeneities in the chalk aquifer water masses at work in the ground water flow and transport: (i) the regional scale linked to the geological context and (ii) the watershed scale linked to the influence of the karst network. Accounting for these heterogeneities in the framework of a regional conceptual model will give a better understanding of the hydrological functioning of the chalk aquifer. This model will also serve as a basis for the parametrization of a physically-based numerical groundwater flow model presently under development. Keywords: Clay-with-Flints, loess, chalk aquifer, sinkholes, nitrates, chlorides, Upper Normandy.
NADM Conceptual Model 1.0 -- A Conceptual Model for Geologic Map Information
North American Geologic Map Data Model (NADM) Steering Committee Data Model Design Team
Executive Summary -- The NADM Data Model Design Team was established in 1999 by the North American Geologic Map Data Model Steering Committee (NADMSC) with the purpose of drafting a geologic map data model for consideration as a standard for developing interoperable geologic map-centered databases by state, provincial, and federal geological surveys. The model is designed to be a technology-neutral conceptual model that can form the basis for a web-based interchange format using evolving information technology (e.g., XML, RDF, OWL), and guide implementation of geoscience databases in a common conceptual framework. The intended purpose is to allow geologic information sharing between geologic map data providers and users, independent of local information system implementation. The model emphasizes geoscience concepts and relationships related to information presented on geologic maps. Design has been guided by an informal requirements analysis, documentation of existing databases, technology developments, and other standardization efforts in the geoscience and computer-science communities. A key aspect of the model is the notion that representation of the conceptual framework (ontology) that underlies geologic map data must be part of the model, because this framework changes with time and understanding, and varies between information providers. The top level of the model distinguishes geologic concepts, geologic representation concepts, and metadata. The geologic representation part of the model provides a framework for representing the ontology that underlies geologic map data through a controlled vocabulary, and for establishing the relationships between this vocabulary and a geologic map visualization or portrayal. Top-level geologic classes in the model are Earth material (substance), geologic unit (parts of the Earth), geologic age, geologic structure, fossil, geologic process, geologic relation, and geologic event.
NSDL National Science Digital Library
From the University of Chicago Press's Journals Division, the Journal of Geology is currently available online free of charge (note: subscription fees may soon apply, but no initiation date is provided). This first-rate technical journal, which publishes "research and theory in geophysics, geochemistry, sedimentology, geomorphology, petrology, plate tectonics, volcanology, structural geology, mineralogy, and planetary sciences" has been in print form since 1893. All of the 1999 issues of the Journal of Geology electronic edition are available here. Internet users can access full-text articles with internal links to references and figures (html, .pdf. .ps).
Digital geologic map of Yellowstone National Park, Idaho, Montana, Wyoming and vicinity
Christiansen, Robert L.; Wahl, Ronald R.
The geology coverage was developed from the 1972 USGS Geologic Map of Yellowstone National Park. It contains polygons of bedrock formations, dikes, and faults. Errors in the 1972 map were corrected and an area outside the Park boundary on the west and south was added. Attributes attached to each polygon include a formation code, formation name, formation age, and a generalized unit name. Line attributes include water, contacts, and faults. Updated information includes a break down of Tertiary, and Quaternary volcanic rock units.
NSDL National Science Digital Library
The link between geology and human health may not seem obvious, but it many ways geology can affect public health in a variety of crucial ways. Certainly, the relationship between geological factors and water and air quality is one that continues to interest policy makers and others. This site explores these issues, and it was created by the people at Carleton College's Professional Development for Geoscience Faculty initiative. Here visitors can make use of a wide range of educational and supporting materials, including classroom activities, key visualizations, and collections of external links. First-time users may wish to start at the "Resources for Educators" area, which includes a brief overview titled "Essential components of geology and human health" and several helpful posters. The remaining materials can be viewed in sections that include "Bookshelf", "Visualizations", and "Internet Resources".
Bedrock Geology Mapping Exercise
NSDL National Science Digital Library
Jim Miller
This field mapping and map-making exercise is a capstone project for a course on Geological Maps. Over a weekend (~12 hours of field work), students collect lithologic and structural data from outcrops scattered over a one square mile area. Back in the classroom, students digitally compile their field data (outcrop, structure measurements, traverse locations) into ArcMAP. They infer geologic linework (faults and contacts) and units from this data in ArcMAP and then export these data layers into Illustrator. In Illustrator, they add ancillary map components (a cross section, description of map units, correlation diagram, map symbol legend,...) to create a final map at a 1:10,000 scale. Their maps are printed out on 11"x17" paper and saved as a pdf file. This exercise helps the students to appreciate how field data is collected and how these geologic facts are interpretively organized into a four-dimensional picture that is a geologic map.
Experiencing Structural Geology
ERIC Educational Resources Information Center
Davis, George H.
Describes an undergraduate structural geology course that incorporates field lab time and research. Lectures, outside readings, and in-class experimentation are coordinated with the field work to prepare a scientific report. (MA)
Stratigraphy and structural geology
NASA Technical Reports Server (NTRS)
Carr, M. H.; Wilhelms, D. E.; Greeley, R.; Guest, J. E.
The immediate goal of stratigraphy and structural geology is to reduce the enormous complexity of a planetary surface to comprehensible proportions by dividing the near-surface rocks into units and mapping their distribution and attitude.
Economic Geology and Education
ERIC Educational Resources Information Center
Geotimes, 1971
Presents tabulated data of questionnaire responses from 207 colleges. More than 30 groups of data are included relating to various aspects of geology programs including enrollment, student and faculty data and courses. (PR)
External Resource: Geology Jeopardy
NSDL National Science Digital Library
This interactive Geology Jeopardy game can by used by the individual to review concepts in earth science or in the classroom as a classroom activity. Topics: rocks, minerals, topography, plate tectonics, weathering, erosion, astronomy, meteorology.
North Dakota Geological Survey
NSDL National Science Digital Library
This is the homepage of the North Dakota Geological Survey. Site materials include information on the state's oil, gas and coal resources, maps, publications, and regulations. The paleontology page features educational articles, information on fossil collecting, articles about fossil exhibits, and information on the state fossil collection. The state GIS hub creates and distributes digital spatial data that conforms to national mapping standards. The teaching tools page includes illustrations and descriptions of rocks and minerals found in the state, as well as information on meteorites and newsletter articles about teaching North Dakota geology. There are also links to landslide maps, surficial geology maps, and links to other survey publications such as reports, bulletins, field studies, other geological and topographic maps, and information on groundwater resources.
Interactive Geologic Timeline Activity
NSDL National Science Digital Library
Environmental Literacy and Inquiry Working Group at Lehigh University
In this learning activity, students use a web-based geologic timeline to examine temperature, CO2 concentration, and ice cover data to investigate how climate has changed during the last 715 million years.
NSDL National Science Digital Library
If you have ever wanted to learn about the geology of Idaho, this site is a great way to explore everything from Coeur d'Alene to the Sawtooth Mountains. This digital version of a course offered at Idaho State University systematically divides Idaho geology into a set of different teaching modules. The modules cover topics like the Idaho Batholith, the Columbia River Basalts, and the Lake Bonneville Flood. Each module contains maps, charts, diagrams, and photographs that illuminate the various geological processes that have formed, and continue to form, in each region of the state. Many of the modules also have fly-throughs that superimpose color-coded geology on 3-D topographic maps to provide a graphic visualization Idaho's rivers. Additionally, the site contains slide shows and a set of teaching exercises.
NSDL National Science Digital Library
The Geologic Hazards section of the US Geological Survey (USGS) conducts research into the causes of geological phenomena such as landslides and earthquakes. The homepage connects visitors to the Geologic Hazards team's three main areas of endeavor. Geomagnetism provides links to the National Geomagnetic Information Center; Magnetic Observatories, Models, and Charts; and the Geomagnetic Information Node, which receives geomagnetic observatory data from around the world. The Landslide group studies the "causes and mechanisms of ground failure" to prevent "long-term losses and casualties." Their section provides links to the program and information center, publications, events, and current projects. The Earthquakes department hosts a wealth of information, including neotectonics, engineering seismology, and paleoseismology. Interactive maps are also provided.
Abstracts of the Annual Meeting of Planetary Geologic Mappers, Flagstaff, AZ, 2010
NASA Technical Reports Server (NTRS)
Bleamaster, Leslie F., III (Editor); Tanaka, Kenneth L. (Editor); Kelley, Michael S. (Editor)
Topics covered include: Detailed Analysis of the Intra-Ejecta Dark Plains of Caloris Basin, Mercury; The Formation and Evolution of Tessera and Insights into the Beginning of Recorded History on Venus: Geology of the Fortuna Tessera Quadrangle (V-2); Geologic Map of the Snegurochka Planitia Quadrangle (V-1): Implications for the Volcanic History of the North Polar Region of Venus; Geological Map of the Fredegonade (V-57) Quadrangle, Venus: Status Report; Geologic Mapping of V-19; Geology of the Lachesis Tessera Quadrangle (V-18), Venus; Comparison of Mapping Tessera Terrain in the Phoebe Regio (V-41) and Tellus Tessera (V-10) Quadrangles; Geologic Mapping of the Devana Chasma (V-29) Quadrangle, Venus; Geologic Mapping of the Aristarchus Plateau Region on the Moon; Geologic Mapping of the Lunar South Pole Quadrangle (LQ-30); The Pilot Lunar Geologic Mapping Project: Summary Results and Recommendations from the Copernicus Quadrangle; Geologic Mapping of the Nili Fossae Region of Mars: MTM Quadrangles 20287, 20282, 25287, 25282, 30287, and 30282; Geologic Mapping of the Mawrth Vallis Region, Mars: MTM Quadrangles 25022, 25017, 25012, 20022, 20017, and 20012; Evidence for an Ancient Buried Landscape on the NW Rim of Hellas Basin, Mars; New Geologic Map of the Argyre Region of Mars: Deciphering the Geologic History Through Mars Global Surveyor, Mars Odyssey, and Mars Express Data; Geologic Mapping in the Hesperia Planum Region of Mars; Geologic Mapping of the Meridiani Region of Mars; Geologic Mapping in Southern Margaritifer Terra; Geology of -30247, -35247, and -40247 Quadrangles, Southern Hesperia Planum, Mars; The Interaction of Impact Melt, Impact-Derived Sediment, and Volatiles at Crater Tooting, Mars; Geologic Map of the Olympia Cavi Region of Mars (MTM 85200): A Summary of Tactical Approaches; Geology of the Terra Cimmeria-Utopia Planitia Highland Lowland Transitional Zone: Final Technical Approach and Scientific Results; Geology of Libya Montes and the Interbasin Plains of Northern Tyrrhena Terra, Mars: First Year Results and Second Year Work Plan; Mars Global Geologic Mapping Progress and Suggested Geographic-Based Hierarchal Systems for Unit Grouping and Naming; Progress in the Scandia Region Geologic Map of Mars; Geomorphic Mapping of MTMS -20022 and -20017; Geologic Mapping of the Medusae Fossae Formation, Mars, and the Northern Lowland Plains, Venus; Volcanism on Io: Results from Global Geologic Mapping; Employing Geodatabases for Planetary Mapping Conduct - Requirements, Concepts and Solutions; and Planetary Geologic Mapping Handbook - 2010.
NSDL National Science Digital Library
This site offers materials on Manitoba geology and minerals, mining and mineral exploration, a Digital Elevation Model of Southern Manitoba (DEMSM) landforms including oblique views, an interactive GIS map gallery of minerals and geology, a study of paleofloods in the Red River Basin including photographs illustrating how scientists delineated the paleofloods, and information on the Manitoba Protected Areas Initiative. Some maps and reports are available to download.
Geologic Time Discussion Analogies
NSDL National Science Digital Library
Noah Fay
The slides provide a fun way of discussing the immensity of geologic time and help to grasp the age of the earth, the time gaps between major geologic events, and the relative minuteness of humans time on earth. After the discussion with the class, students are given opportunity to develop their own analogies using "everyday" things (other than the calendar and money examples used in this activity).
Interpreting Geologic Sections
NSDL National Science Digital Library
Paul Morris
Athro, Limited is a for-profit corporation that publishes high school and college level biology, earth science, and geology course supplements and independent learning materials on the Web. This site provides instruction in interpreting the order of events in three hypothetical and one real geological section. For each section there is a list of events and an animation of the history of the section once the student has decided on the order of events.
Separation of climate- and geology-induced variations in the hydrological response of a regional karstified aquifer: determination of a geologic transfer function
NASA Astrophysics Data System (ADS)
Slimani, S.; Massei, N.; Dupont, J.-P.; Mesquita, J.; Laignel, B.
Worldwide, karst hydrosystems represent a great potential in terms of water ressources. However, such heterogenous systems are characterized by a highly non-linear response to input signals. In the region of Upper Normandy (Northwestern France), where almost 100% of drinking water supply comes from ground water, the Chalk karst aquifer is characterized by the presence of a thick surficial formations cover which is unequally distributed over the area according to the regional geological context. This structural context also implies a significant spatial variability of the aquifer thickness. To assess the overall hydrologic variability of this aquifer, we use long-term hydraulic head and precipitation time series (20 years) to analyse their relationships according to such specific geological conditions. By continuous wavelet transform, the hydraulic head time series were found to exhibit long-term variations that represented a great amount of variance in some locations, what we could eventually relate to climate-induced oscillations. This was particularly the case of those locations where the aquifer thickness was important. The climate-induced oscillations found were of the order of 2-3-yr and 5-6-yr which would well correspond to some modes of oscillation linked to the positive/negative regimes of the North Atlantic Oscillation. In addition, the corresponding variations in hydrological time series exhibited a clear increase in the explanation of total variance from the early 90's up to the end of the series. In a second time, in order to assess the role of the geological medium in the precipitation/head relationship, we proposed to filter out those long-term spectral components inherent to climate fluctuations. This allowed identification of the head response to precipitation throughout the entire 20-yr period of study for short-term infra-annual time scales. Cross-correlation between the input and output signals after filtering out of long-term components showed that response times to precipitations ranged from a few days to 6 months, which was not detectable by performing the same analysis on raw time series. These response times, corresponding either to recharge time of the aquifer or to karst-network connections reactivity, are strongly related to the geological and geomorphological contexts (thickness of surficial formations, downstream parts of the aquifer near karst outlets in valleys). The cross-correlation functions would then be representative (with a precipitation white noise-like input) of a so-called geologic transfer function which is ensured to define the filtering properties of the medium and then display spatial variations in the region studied. Keywords: geologic structure, karstic chalk aquifer, Upper Normandy, cross-correlation analysis, continuous wavelet analysis, filtring, geologic transfer function, annual and multi-year variability.
Origins of Anomalous Transport in Heterogeneous Media: Structural and Dynamic Controls
NASA Astrophysics Data System (ADS)
Edery, Yaniv; Guadagnini, Alberto; Scher, Harvey; Berkowitz, Brian
Anomalous (or 'non-Fickian') transport is ubiquitous in the context of tracer migration in geological formations. We quantitatively identify the origin of anomalous transport in a representative model of a heterogeneous porous medium under uniform (in the mean) flow conditions; we focus on anomalous transport which arises in the complex flow patterns of lognormally distributed hydraulic conductivity (K) fields, with several decades of K values. Transport in the domains is determined by a particle tracking technique and characterized by breakthrough curves (BTCs). The BTC averaged over multiple realizations demonstrates anomalous transport in all cases, which is accounted for entirely by a power-law distribution ~ t-1-? of local transition times, contained in the probability density function ?(t) of transition times, using the framework of a continuous time random walk (CTRW). A unique feature of our analysis is the derivation of ?(t) as a function of parameters quantifying the heterogeneity of the domain. In this context, we first establish the dominance of preferential pathways across each domain, and characterize the statistics of these pathways by forming a particle-visitation weighted histogram Hw(K). By converting the ln(K) dependence of Hw(K) into time, we demonstrate the equivalence of Hw(K) and ?(t), and delineate the region of Hw(K) that forms the power law of ?(t). This thus defines the origin of anomalous transport. Analysis of the preferential pathways clearly demonstrates the limitations of critical path analysis and percolation theory as a basis for determining the origin of anomalous transport. Furthermore, we derive an expression defining the power law exponent ? in terms of the Hw(K) parameters. The equivalence between Hw(K) and ?(t) is a remarkable result, particularly given the nature of the K heterogeneity, the complexity of the flow field within each realization, and the statistics of the particle transitions.
Origins of anomalous transport in heterogeneous media: Structural and dynamic controls
NASA Astrophysics Data System (ADS)
Edery, Yaniv; Guadagnini, Alberto; Scher, Harvey; Berkowitz, Brian
Anomalous (or "non-Fickian") transport is ubiquitous in the context of tracer migration in geological formations. We quantitatively identify the origin of anomalous transport in a representative model of a heterogeneous porous medium under uniform (in the mean) flow conditions; we focus on anomalous transport which arises in the complex flow patterns of lognormally distributed hydraulic conductivity (K) fields, with several decades of K values. Transport in the domains is determined by a particle tracking technique and characterized by breakthrough curves (BTCs). The BTC averaged over multiple realizations demonstrates anomalous transport in all cases, which is accounted for entirely by a power law distribution śt-1-? of local transition times. The latter is contained in the probability density function ?(t) of transition times, embedded in the framework of a continuous time random walk (CTRW). A unique feature of our analysis is the derivation of ?(t) as a function of parameters quantifying the heterogeneity of the domain. In this context, we first establish the dominance of preferential pathways across each domain, and characterize the statistics of these pathways by forming a particle-visitation weighted histogram, Hw>(K>), of the hydraulic conductivity. By converting the ln(K) dependence of Hw>(K>) into time, we demonstrate the equivalence of Hw>(K>) and ?(t), and delineate the region of Hw>(K>) that forms the power law of ?(t). This thus defines the origin of anomalous transport. Analysis of the preferential pathways clearly demonstrates the limitations of critical path analysis and percolation theory as a basis for determining the origin of anomalous transport. Furthermore, we derive an expression defining the power law exponent ? in terms of the Hw>(K>) parameters. The equivalence between Hw>(K>) and ?(t) is a remarkable result, particularly given the nature of the K heterogeneity, the complexity of the flow field within each realization, and the statistics of the particle transitions.
NSDL National Science Digital Library
The US Geological Survey Geology in the Parks Web site is a cooperative project of the USGS Western Earth Surface Processes Team and the National Park Service. This extensive site covers geologic maps, plate tectonics, rocks and minerals, geologic time, US geologic provinces, park geology of the Mojave, Sunset Crater, Lake Mead, North Cascades, Death Valley, Yosemite National Park, and much more. Descriptions, graphics, photographs, and animations all contribute to this informative and interesting Web site making it a one stop, all encompassing, resource for everything geology and US national park related.
Illustrated Glossary of Geologic Terms
NSDL National Science Digital Library
Provided by the Geology Department at Iowa State University, this handy illustrated glossary of geological terms is an excellent quick reference resource for students. Continuously upgraded with links to illustrations and text, this geological lexicon is based on the glossary in the textbook Earth: An Introduction to Geological Change by S. Judson and S.M. Richardson. Alphabetical tabs and internal links to related terms let users move quickly around this useful aid for geology students.
A Stochastic Non-Gaussian Velocity Model for Tracer Dispersion in Heterogeneous Porous Media
NASA Astrophysics Data System (ADS)
Meyer, D. W.; Tchelepi, H. A.
To model tracer transport in porous media, computationally expensive Monte Carlo (MC) techniques or low-order approximation methods (LOAM) are applicable [1]. The latter are inexpensive but limited to relatively homogeneous media with low conductivity or transmissivity variations, and approximately Gaussian one-point velocity statistics. MC studies have shown that heterogeneous media lead to distinctly skewed non-Gaussian velocity distributions [2]. In addition to MC and LOAM, continuous time random walk (CTRW) or Lķvy motion (LM) approaches were proposed for the modeling of dispersion in highly heterogeneous media, e.g, fractured rock [3,4]. Both models involve discontinuous stochastic processes for the displacement of tracer particles. The parameters that determine these processes, however, are not always easy to identify. In this work, a new particle-based model for the simulation of tracer dispersion in homogeneous and heterogeneous porous media is presented. Other than in CTRW or LM models, a continuous stochastic process for the Lagrangian velocity of a tracer particle is formulated. The suggested formulation encompasses Gaussian and skewed velocity statistics, and the model parameters can be related more easily to medium characteristics. Numerical simulations of the tracer plume evolution in the Borden tracer experiment and of breakthrough curves in homogeneous and uniformly heterogeneous sand packs are successfully validated with experimental data [5,6]. Non-Fickian dispersion behavior resulting from the scale effect (plume-size dependent dispersivities) and skewed velocity statistics is demonstrated and analyzed. [1] Zhang, Y. K. and D. Zhang (2004). "Forum: The state of stochastic hydrology." Stochastic Environmental Research and Risk Assessment 18(4): 265-265. [2] Salandin, P. and V. Fiorotto (1998). "Solute transport in highly heterogeneous aquifers." Water Resources Research 34(5): 949-961. [3] Benson, D. A., R. Schumer, et al. (2001). "Fractional Dispersion, Lķvy Motion, and the MADE Tracer Tests." Transport in Porous Media 42(1): 211-240. [4] Berkowitz, B., A. Cortis, et al. (2006). "Modeling non-Fickian transport in geological formations as a continuous time random walk." Reviews of Geophysics 44(2). [5] Freyberg, D. L. (1986). "A Natural Gradient Experiment on Solute Transport in a Sand Aquifer. 2. Spatial Moments and the Advection and Dispersion of Nonreactive Tracers." Water Resources Research 22(13): 2031-2046. [6] Silliman, S. E. and E. S. Simpson (1987). "Laboratory Evidence of the Scale Effect in Dispersion of Solutes in Porous-Media." Water Resources Research 23(8): 1667-1673.
Geology and plate-tectonic development
Irwin, W.P.
The San Andreas fault is a transform fault along the boundary between the Pacific and North American plates. Bedrock along the fault includes various lithologic units that range in age from Precambrian to Tertiary and younger. Some bedrock units that can be matched across the fault suggest strike-slip displacement of as much as 560 km. This chapter describes geologic formations of northern and central California, including Franciscan rocks, Coast Range ophiolite, Great Valley sequence, Coast Range thrust, Salinian block, displacement of pre-Quaternary rocks by the San Andreas fault, and the relation of geologic structure to seismic behavior. Formations of southern California which are described are the Transverse Ranges and the Salton Trough and displacement of basement rocks by the San Andreas fault. Plate-tectonic development of the San Andreas fault is also discussed.
Medium Frequency Pseudo Noise Geological Radar
NASA Technical Reports Server (NTRS)
Arndt, G. Dickey (Inventor); Carl, James R. (Inventor); Byerly, Kent A. (Inventor); Amini, B. Jon (Inventor)
System and methods are disclosed for transmitting and receiving electromagnetic pulses through a geological formation. A preferably programmable transmitter having an all-digital portion in a preferred embodiment may be operated at frequencies below 1 MHz without loss of target resolution by transmitting and over sampling received long PN codes. A gated and stored portion of the received signal may be correlated with the PN code to determine distances of interfaces within the geological formation, such as the distance of a water interfaces from a wellbore. The received signal is oversampled preferably at rates such as five to fifty times as high as a carrier frequency. In one method of the invention, an oil well with multiple production zones may be kept in production by detecting an approaching water front in one of the production zones and shutting down that particular production zone thereby permitting the remaining production zones to continue operating.
Modeling the establishment of preferential flow during infiltration in a heterogeneous glaciofluvial deposit
NASA Astrophysics Data System (ADS)
Ben Slimene, Erij; Lassabatere, Laurent; Winiarski, Thierry; Gourdon, Remy
Large cities are mostly situated in areas close to water resources in order to meet the water needs of their populations. Alluvial soils harbor large aquifers that are used to supply water, the Rhone-Alpes region being a good illustration. However, the increase of soil sealing has led to the development of best management practices such as infiltration basins which are aimed at infiltrating stormwater in order to reduce the amount of water collected and treated in usual systems. Yet, these infiltration basins are mainly settled over highly permeable geologic formations so as to ensure water infiltration and a proper functioning of these infiltration basins. Most of these formations are strongly heterogeneous, since they are made of different materials with contrasting sedimentological properties (e.g. particle size distribution) and transfer properties. This paper addresses flow modeling during the infiltration phase in the vadose zone underneath infiltration basins settled over a strongly heterogeneous glaciofluvial deposit. In particular, we want to pinpoint numerically the worst conditions with regards to preferential flow, in terms of initial hydric conditions (initial water contents) and imposed flow rates. For this purpose, a numerical study is proposed on the basis of previous studies offering a sedimentological description of the subsoil with the detail of its architecture and a precise description of the different lithofacies and their hydraulic properties. Considering this, we worked on a section (13.5m long and 2.5m high) for which a complete sedimentological and hydraulic description had already been performed. Water infiltration was modeled for different initial and boundary conditions (mostly the values of the flux imposed at surface). At first, different numerical tests and adjustments have been made including mesh optimization with regards to both accuracy and computation time. Following these tests, the "tight" mesh has been validated since it proved to be necessary for the detection of preferential flow. Then, a sensitivity analysis addressed the role of initial and boundary conditions on the establishment of preferential flow. According to these conditions, the time required to reach steady state over the whole soil profile, wetting fronts and water fluxes during transient state and water fluxes at steady state were accurately characterized and compared to those of a uniform section. These results are quite counter-intuitive and suggest that unsaturated flow can favor preferential flow, mostly for low water fluxes imposed at surface. In addition, these results are relevant with regards to ongoing researches on the fate of pollutants into heterogeneous deposits. These data are of a great interest since they allow generating a conceptual and numerical model to better understand and predict the development of preferential flows and their impact on pollutant transfer in highly heterogeneous glaciofluvial deposits.
Role of Biofilms in Geological Carbon Sequestration
Robin Gerlach; Andrew C. Mitchell; Lee H. Spangler; Al B. Cunningham
Geologic sequestration of CO2 involves injection into underground formations including oil beds, deep un-minable coal seams, and deep saline aquifers with temperature and pressure conditions such that CO2 will likely be in the supercritical state. Supercritical CO2 (scCO2) is only slightly soluble in water (approximately 4%) and it is therefore likely that two fluid phases will develop in the subsurface,
Geologic effects of hurricanes
NASA Astrophysics Data System (ADS)
Coch, Nicholas K.
Hurricanes are intense low pressure systems of tropical origin. Hurricane damage results from storm surge, wind, and inland flooding from heavy rainfall. Field observations and remote sensing of recent major hurricanes such as Hugo (1989), Andrew (1992) and Iniki (1992) are providing new insights into the mechanisms producing damage in these major storms. Velocities associated with hurricanes include the counterclockwise vortex winds flowing around the eye and the much slower regional winds that steer hurricane and move it forward. Vectorial addition of theseof these two winds on the higher effective wind speed than on the left side. Coast-parallel hurricane tracks keep the weaker left side of the storm against the coast, whereas coast-normal tracks produce a wide swath of destruction as the more powerful right side of the storm cuts a swath of destruction hundreds of kilometers inland. Storm surge is a function of the wind speed, central pressure, shelf slope, shoreline configuration, and anthropogenic alterations to the shoreline. Maximum surge heights are not under the eye of the hurricane, where the pressure is lowest, but on the right side of the eye at the radius of maximum winds, where the winds are strongest. Flood surge occurs as the hurricane approaches land and drives coastal waters, and superimposed waves, across the shore. Ebb surge occurs when impounded surface water flows seaward as the storm moves inland. Flood and ebb surge damage have been greatly increased in recent hurricanes as a result of anthropogenic changes along the shoreline. Hurricane wind damage occurs on three scales Ś megascale, mesoscale and microscale. Local wind damage is a function of wind speed, exposure and structural resistance to velocity pressure, wind drag and flying debris. Localized extreme damage is caused by gusts that can locally exceed sustained winds by a factor of two in areas where there is strong convective activity. Geologic changes occuring in hurricanes include beach erosion, dune erosion, inlet formation from flood and ebb surge, landscape changes through tree destruction by wind and nearshore channeling and sedimentation resulting from ebb surge. Multi-decadal wet and dry cycles in West Africa seem to be associated with increases (wet periods) and decreases (dry periods) in the frequency of Atlantic Coast landfalling hurricanes. Coastalzone population and development has increased markedly in a time of low hurricane frequency in the 24 year dry cycle from1970 to the present. However, no previous climatic cycle in this century has exceeded 26 years. We may entering a multi-decadal cycle of greater hurricane activity, placing these highly urbanized shorelines in considerable danger.
Designing and implementing a geologic information system using a spatiotemporal ontology model for a geologic map of Korea
NASA Astrophysics Data System (ADS)
Hwang, Jaehong; Nam, Kwang Woo; Ryu, Keun Ho
A geologic information system was utilized for geologic mapping in Korea using a spatiotemporal ontology model. Five steps were required to make the GIS representation of the geologic map information. The first step was to limit the geologic mapping to Korean area. The second step was to extract the rock units with spatial objects from the geologic map and the geologic time units with temporal objects. The third step was to standardize the geologic terms in Korean and English for both the spatial and temporal objects. The fourth step was to conceptualize the classified objects in the geologic map units and the formation of guidelines for the specification of a spatiotemporal ontology model. Finally, we constructed a spatiotemporal retrieval system and an ontology system related to the geologic map of Korea, which were applied to the spatiotemporal ontology model. The spatiotemporal ontology model was defined as a sophisticated model that provides for the evolution from a data base to a knowledge base. This ontology model can be conceptualized as a well-defined set of terms used for expressing spatial objects in rock units and temporal objects in geologic time units, as well as a system of contents and structures. In addition, it includes symbology units such as color and pattern symbols mapped one-to-one with the spatiotemporal concepts. The existing information retrieval services provide information that is limited to the user's knowledge, whereas our geologic ontology system provides a broad range of information in graphical form, including locations and interrelationships. In this way, the information can be upgraded to the level of knowledge. A geologic term tree was designed, based on the existing classification schemes, with the goal of creating an accessible internet source.
Russia's contribution to regional geologic mapping of Venus
NASA Technical Reports Server (NTRS)
Burba, G. A.; Bobina, N. N.; Shashkina, V. P.
Geologic maps in Magellan C1-format were produced by six geologists and three cartographer in Russia during 1992. More sheets are in progress. The work is coordinated by Vernadsky Institute. The Magellan SRR images in form of C1-format photomaps were used as a base for geologic-geomorphic regional mapping of Venus at approximately 1:8,000,000 scale. This work took place in Russia at Vernadsky Institute and at the Department of Geology, Lomonosov Moscow University. The aim is to produce a preliminary geologic survey of Venus with the new high resolution images obtained by Magellan. It took place at the cartographic division, Laboratory of Comparative Planetology and Meteoritics, Vernadsky Institute, Russsia's Academy of Sciences.
Geologic and Mineral Resource Map of Afghanistan
Doebrich, Jeff L.; Wahl, Ronald R.; With Contributions by Ludington, Stephen D.; Chirico, Peter G.; Wandrey, Craig J.; Bohannon, Robert G.; Orris, Greta J.; Bliss, James D.; Wasy, Abdul; Younusi, Mohammad O.
Data Summary The geologic and mineral resource information shown on this map is derived from digitization of the original data from Abdullah and Chmyriov (1977) and Abdullah and others (1977). The U.S. Geological Survey (USGS) has made no attempt to modify original geologic map-unit boundaries and faults as presented in Abdullah and Chmyriov (1977); however, modifications to map-unit symbology, and minor modifications to map-unit descriptions, have been made to clarify lithostratigraphy and to modernize terminology. Labeling of map units has not been attempted where they are small or narrow, in order to maintain legibility and to preserve the map's utility in illustrating regional geologic and structural relations. Users are encouraged to refer to the series of USGS/AGS (Afghan Geological Survey) 1:250,000-scale geologic quadrangle maps of Afghanistan that are being released concurrently as open-file reports. The classification of mineral deposit types is based on the authors' interpretation of existing descriptive information (Abdullah and others, 1977; Bowersox and Chamberlin, 1995; Orris and Bliss, 2002) and on limited field investigations by the authors. Deposit-type nomenclature used for nonfuel minerals is modified from published USGS deposit-model classifications, as compiled in Stoeser and Heran (2000). New petroleum localities are based on research of archival data by the authors. The shaded-relief base is derived from Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) data having 85-meter resolution. Gaps in the original SRTM DEM dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). The marginal extent of geologic units corresponds to the position of the international boundary as defined by Abdullah and Chmyriov (1977), and the international boundary as shown on this map was acquired from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af) in September 2005. Non-coincidence of these boundaries is due to differences in the respective data sources and to inexact registration of the geologic data to the DEM base. Province boundaries, province capital locations, and political names were also acquired from the AIMS Web site in September 2005. The AIMS data were originally derived from maps produced by the Afghanistan Geodesy and Cartography Head Office (AGCHO). Version 2 differs from Version 1 in that (1) map units are colored according to the color scheme of the Commission for the Geological Map of the World (CGMW) (http://www.ccgm.org), (2) the minerals database has been updated, and (3) all data presented on the map are also available in GIS format.
Geology Before Pluto: Pre-encounter Considerations
NASA Astrophysics Data System (ADS)
Moore, Jeffrey
Jeffrey M. Moore (NASA Ames) and the New Horizons Science Team Pluto, its large satellite Charon, and its four small known satellites represent the first trans-Neptunian Kuiper Belt objects populating the outer-most solar system beyond the gas giant planets to be studied in detail from a spacecraft (New Horizons). A complete picture of the solar nebula and solar system formation cannot be confidently formulated until representatives of this group of bodies at the edge of solar space have been examined. The Pluto system is composed of unique, lunar- and intermediate-sized objects that can tell us much about how objects with volatile icy compositions evolve. Modeling of the interior suggests that geologic activity may have been significant to some degree, and observations of frost on the surface could imply the need for a geologic reservoir for the replenishment of these phases. However, these putative indicators of Pluto's geologic history are inconclusive and unspecific. Detailed examination of Pluto's geologic record is the only plausible means of bridging the gap between theory and observation. In this talk I will examine the potential importance of these tentative indications of geologic activity and how specific spacecraft observations have been designed and used to constrain the Pluto system's geologic history. The cameras of New Horizons will provide robust data sets that should be immanently amenable to geological analysis of the Pluto System's landscapes. In this talk, we begin with a brief discussion of the planned observations by the New Horizons cameras that will bear most directly on geological interpretability. Then I will broadly review major geological processes that could potentially operate on the surfaces of Pluto and its moons. I will first survey exogenic processes (i.e. those for which energy for surface modification is supplied externally to the planetary surface): impact cratering, sedimentary processes (including volatile migration), and the work of wind. I will conclude with an assessment of the prospects for endogenic activity in the form of tectonics and cryo-volcanism.
Water Challenges for Geologic Carbon Capture and Sequestration
Robin L. NewmarkSamuel; Samuel J. Friedmann; Susan A. Carroll
Carbon capture and sequestration (CCS) has been proposed as a means to dramatically reduce greenhouse gas emissions with the\\u000a continued use of fossil fuels. For geologic sequestration, the carbon dioxide is captured from large point sources (e.g.,\\u000a power plants or other industrial sources), transported to the injection site and injected into deep geological formations\\u000a for storage. This will produce new
William D. Heran; Gregory N. Green; Douglas B. Stoeser
This report consists of a compilation of twelve digital geologic maps provided in ARC\\/INFO interchange (e00) format for the state of Oklahoma. The source maps consisted of nine USGS 1:250,000-scale quadrangle maps and three 1:125,000 scale county maps. This publication presents a digital composite of these data intact and without modification across quadrangle boundaries to resolve geologic unit discontinuities. An
Mars Geologic Mapping: a Review and New Concepts
NASA Technical Reports Server (NTRS)
Scott, D. H.; Tanaka, K. L.
The final version of the 1.15 m scale geologic map of the western equatorial region of Mars based on Viking pictures has been completed in open file format. Geologic maps of the north and south polar regions were completed in provisional form. A map of the eastern equatorial region is in compilation. Evidences of erosion, water flooding, volcanic activity, and primary and satellite craters in these areas are discussed.
Cigeo, the French Geological Repository Project - 13022
Labalette, Thibaud; Harman, Alain; Dupuis, Marie-Claude; Ouzounian, Gerald [ANDRA, 1-7, rue Jean Monnet, 92298 Chatenay-Malabry Cedex (France)] [ANDRA, 1-7, rue Jean Monnet, 92298 Chatenay-Malabry Cedex (France)
The Cigeo industrial-scale geological disposal centre is designed for the disposal of the most highly-radioactive French waste. It will be built in an argillite formation of the Callovo-Oxfordian dating back 160 million years. The Cigeo project is located near the Bure village in the Paris Basin. The argillite formation was studied since 1974, and from the Meuse/Haute-Marne underground research laboratory since end of 1999. Most of the waste to be disposed of in the Cigeo repository comes from nuclear power plants and from reprocessing of their spent fuel. (authors)
What is a Geologic Map and How is it Used?
NSDL National Science Digital Library
G. Whittecar
In this activity students draw a geologic map based on a teacher-prepared terrain model with outcrops placed across the landscape according to a predetermined pattern to represent flat, tilted, folded, and/or faulted strata. Students will map the outcrops and indicate their strike, dip and draw lines to indicate contacts. As a result of this activity students will understand how geologists use geologic maps to predict locations of unseen rocks after they record observations on base maps, classify data, and analyze map patterns. Students will also understand relationships between outcrops, contacts, formations, and geologic structures.
Geologic mapping of tunnels using photogrammetry: Camera and target positioning
Coe, J.A. [Geological Survey, Denver, CO (United States); Dueholm, K.S. [Danmarks Tekniske Hoejskole, Lyngby (Denmark). Inst. of Surveying and Photogrammetry
A photogrammetric method has been developed by the US Geological Survey and the US Bureau of Reclamation for the use in geologic mapping of tunnels (drifts). The method requires photographing the tunnel walls and roof with a calibrated small-format camera to obtain stereo pairs of photos which are then oriented in an analytical stereo plotter for measurement of geologic features. The method was tested in G-tunnel at Rainier Mesa on the Nevada Test Site. Calculations necessary to determine camera and target positions and problems encountered during testing were used to develop a set of generic formulas that can be applied to any tunnel. 7 figs.
Geological research for public outreach and education in Lithuania
NASA Astrophysics Data System (ADS)
Skridlaite, Grazina; Guobyte, Rimante
Successful IYPE activities and implementation of Geoheritage day in Lithuania increased public awareness in geology. A series of projects introducing geology to the general public and youth, supported by EU funds and local communities, were initiated. Researchers from the scientific and applied geology institutions of Lithuania participated in these projects and provided with the geological data. In one case, the Lithuanian Survey of Protected Areas supported the installation of a series of geological exhibitions in several regional and national parks. An animation demonstrating glacial processes was chosen for most of these because the Lithuanian surface is largely covered with sedimentary deposits of the Nemunas (Weichselian) glaciation. Researchers from the Lithuanian Geological Survey used the mapping results to demonstrate real glacial processes for every chosen area. In another case, 3D models showing underground structures of different localities were based on detailed geological maps and profiles obtained for that area. In case of the Sartai regional park, the results of previous geological research projects provided the possibility to create a movie depicting the ca. 2 Ga geological evolution of the region. The movie starts with the accretion of volcanic island arcs on the earlier continental margin at ca. 2 Ga and deciphers later Precambrian tectonic and magmatic events. The reconstruction is based on numerous scientific articles and interpretation of geophysical data. Later Paleozoic activities and following erosion sculptured the surface which was covered with several ice sheets in Quaternary. For educational purpose, a collection of minerals and rocks at the Forestry Institute was used to create an exhibition called "Cycle of geological processes". Forestry scientists and their students are able to study the interactions of geodiversity and biodiversity and to understand ancient and modern geological processes leading to a soil formation. An aging exposition at the Museum of Erratic Boulders in NW Lithuania is being rearranged for educational purposes, to show the major rock types and their origins more clearly. A new exhibition is supplemented with computer portals presenting geological processes, geological quizzes, animations etc. Magmatism, metamorphism, sedimentation and other geological processes are demonstrated using erratic boulders brought by glaciers from Scandinavia and northern Russia. A part of the exhibition is devoted to glaciation processes and arrival of ice sheets to Lithuania. Visitors are able to examine large erratic boulder groups in a surrounding park and to enjoy beautiful environment. The exhibition also demonstrates mineral resources of Lithuania, different fossils and stones from a human body. In all cases it was recognised that a lack of geological information limits the use of geology for public outreach. Ongoing scientific research is essential in many places as well as a mediator's job for interpreting the results of highly specialised research results and to adapt them for public consumption.
Review of strategies for handling geological uncertainty in groundwater flow and transport modeling
NASA Astrophysics Data System (ADS)
Refsgaard, Jens Christian; Christensen, Steen; Sonnenborg, Torben O.; Seifert, Dorte; H°jberg, Anker Lajer; Troldborg, Lars
The geologically related uncertainty in groundwater modeling originates from two main sources: geological structures and hydraulic parameter values within these structures. Within a geological structural element the parameter values will always exhibit local scale heterogeneity, which can be accounted for, but is often neglected, in assessments of prediction uncertainties. Strategies for assessing prediction uncertainty due to geologically related uncertainty may be divided into three main categories, accounting for uncertainty due to: (a) the geological structure; (b) effective model parameters; and (c) model parameters including local scale heterogeneity. The most common methodologies for uncertainty assessments within each of these categories, such as multiple modeling, Monte Carlo analysis, regression analysis and moment equation approach, are briefly described with emphasis on their key characteristics. Based on reviews of previous studies, assessments are made on the relative importance of the three uncertainty categories for different types of model predictions. Furthermore, the strengths, limitations and interactions of these methodologies are discussed and conclusions are made with respect to identifying key subjects for which further research is needed. When all sources of uncertainty are analyzed by exploring model parameter and local scale heterogeneity uncertainty for several plausible geological model structures the joint uncertainties can be assessed by use of model averaging techniques, such as Bayesian Model Averaging (BMA). General challenge in model averaging with respect to choosing mutually exclusive and collectively exhaustive choice models, as well as to assign weights when models are used beyond their calibration base, are discussed.
NSDL National Science Digital Library
Maher, Louis J.
In 1966, Professor Louis J. Maher of the University of Wisconsin-Madison's Department of Geology and Geophysics piloted a department-owned Cessna over the continental US taking photos for use in his geology courses. As Maher flew, his trusty co-pilot and graduate assistant, Charles Mansfield, snapped the photos. The resulting collection is an assortment of breathtaking images of classic geological features, now available online for noncommercial use by educators (download via FTP). Maher gives us birds-eye views of structural features in Wyoming's Wind River Range, sedimentary strata in Arches National Park and the Grand Canyon, glacial landscapes in Northern Minnesota, and ancient lava flows in Arizona, to name just a few.
NASA Technical Reports Server (NTRS)
Shoemaker, E. M.; Lucchitta, B. K.; Wilhelms, D. E.; Plescia, J. B.; Squyres, S. W.
A broad outline of the geologic history of Ganymede is presented, obtained from a first attempt to map the geology on a global scale and to interpret the characteristics of the observed geologic units. Features of the ancient cratered terrain such as craters and palimpsests, furrows and troughs, are discussed. The grooved terrain is described, including its sulci and cells, and the age relation of these units is considered along with the structure and origin of this terrain. The Gilgamesh Basin and Western Equatorial Basin in the post grooved terrain are treated, as are the bright and dark ray craters and the regolith. The development of all these regions and features is discussed in context. For the regolith, this includes the effect of water migration, sputtering, and thermal annealing. The histories of the ancient cratered terrain, the grooved terrain, and the post grooved terrain are presented.
NSDL National Science Digital Library
Established in 1872 by the State of Minnesota as part of the University of Minnesota, the Minnesota Geological Survey (MGS) serves the people of Minnesota by providing systematic geoscience information to support the stewardship of water, land, and mineral resources. This rather lovely digital collection brings together a record of all items published by the MGS since its creation. Here, visitors will find documents, reports, maps, and GIS data for online viewing or downloading as well. The thematic collections here include the Aeromagnetic Map Series, the annual reports of the Minnesota Geological and Natural History Survey, and the wonderful county atlas series. Visitors with a penchant for geology, natural history, and geography will find much to enjoy here.
Sedimentology and petroleum geology
Bjorlykke, K.
In this introduction to sedimentology and petroleum geology the subjects, which are closely related but mostly treated separately, are integrated. The first part covers the basic aspects of sedimentology, sedimentary geochemistry and diagenesis, including brief discussions of flow in rivers and channels, types of sediment transport, lake and river deposits, deltas (river-dominated, tide-dominated, and wave-dominated) and the water budget. Principles of stratigraphy, seismic stratigraphy and basin modeling form the basis for the last part on petroleum geology. Here subjects include the composition of kerogen and hydrocarbons, theories of migration and trapping of hydrocarbons and properties of reservoir rocks. Finally, short introductions to well logging and production geology are given.
Global sedimentary geology program
Ginsburg, R.N.; Clifton, H.E.; Weimer, R.J.
The Society of Economic Paleontologists and Mineralogists, in collaboration with the International Association of Sedimentologists and the International Union of Geological Sciences Committee on Sedimentology, is developing a new international study under the provisional title of Global Sedimentary Geology Program (GSGP). Initially, three research themes are being considered: (1) event stratigraphy-the documentation of examples of mass extinctions, eustatic fluctuations in sea level, major episodes of volcanisms, and changes in ocean composition; (2) facies models in time and space-an expansion of the existing data base of examples of facies models (e.G., deltas, fluvial deposits, and submarine fans) and global-scale study of the persistence of facies at various times in geologic history; and (3) sedimentary indices of paleogeography and tectonics-the use of depositional facies and faunas in paleogeography and in assessing the timing, locus, and characteristics of tectonism. Plans are being developed to organize pilot projects in each of these themes.
NASA Astrophysics Data System (ADS)
Ruffell, Alastair; Majury, Niall; Brooks, William E.
Some geological fakes and frauds are carried out solely for financial gain (mining fraud), whereas others maybe have increasing aesthetic appeal (faked fossils) or academic advancement (fabricated data) as their motive. All types of geological fake or fraud can be ingenious and sophisticated, as demonstrated in this article. Fake gems, faked fossils and mining fraud are common examples where monetary profit is to blame: nonetheless these may impact both scientific theory and the reputation of geologists and Earth scientists. The substitution or fabrication of both physical and intellectual data also occurs for no direct financial gain, such as career advancement or establishment of belief (e.g. evolution vs. creationism). Knowledge of such fakes and frauds may assist in spotting undetected geological crimes: application of geoforensic techniques helps the scientific community to detect such activity, which ultimately undermines scientific integrity.
NSDL National Science Digital Library
This Geological Survey of Ireland website can increase the public's excitement about geology by offering simple, straightforward materials on the basics of geology. The website is divided into numerous themes such as Volcanoes, Rocks, Caves, and the Water Cycle. The links from each of the headings introduce the topic with simple descriptions and remarkable pictures and offer easy experiments when applicable. Students and educators can take virtual tours of the Ox Mountains, Killiney Beach, and other Irish landscapes. Everyone should visit the Landscapes for the Living link, which offers outstanding images of the diverse landscapes of Europe. While some of the themes are currently under construction, including Planet Earth, Plate Tectonics, and Earthquakes, the authors indicate that these materials will be added in the near future.
NSDL National Science Digital Library
Randall Richardson
After having talked about the geologic time scale (Precambrian: prior to 570 Ma; Paleozoic: 570-245 Ma; Mesozoic: 245-65 Ma; Cenozoic: 65 Ma - Present), I ask for two volunteers from the class to hold a rope that is 50 feet long. I say that one end is the beginning of the Earth (4.6 billion years ago), and the other is today. I then give out 16 clothes pins and ask various students to put a cloths pin on the 'time line' at various 'geologic events'. For example, I ask them to put one where the dinosaurs died out (end of the Mesozoic). They almost invariably put it much too old (65 Ma is less than 2% of Earth history!). Then I ask them to put one on their birthday (they now laugh). Then I ask them to put one where we think hominoids (humans) evolved (~3-4 Ma), and they realize that we have not been here very long geologically. Then I ask them to put one at the end of the Precambrian, where life took off in terms of the numbers of species, etc. They are amazed that this only represents less than 15% of Earth history. Throughout the activity I have a quiz going on where the students calculate percentages of Earth History for major geologic events, and compare it to their own ages. On their time scale, the dinosaurs died only about two 'months' ago! The exercise is very effective at letting them get a sense of how long geologic time is, and how 'recently' some major geologic events happened when you consider a time scale that is the age of the earth.
PTOLEMY II HETEROGENEOUS CONCURRENT MODELING AND DESIGN IN JAVA Edited by: Christopher Hylands: INTRODUCTION TO PTOLEMY II Authors: Shuvra S. Bhattacharyya Elaine Cheong John Davis, II Mudit Goel Bart of Electrical Engineering and Computer Sciences University of California at Berkeley http://ptolemy
-PTOLEMY II - HETEROGENEOUS CONCURRENT MODELING AND DESIGN IN JAVA John Davis, II Mudit Goel University of California at Berkeley http://ptolemy.eecs.berkeley.edu Memorandum UCB/ERL M99/40 Document Contents Part 1: Using Ptolemy II 1. Introduction 1-1 1.1.Modeling and Design 1-1 1.2.Architecture Design 1
PTOLEMY II HETEROGENEOUS CONCURRENT MODELING AND DESIGN IN JAVA Edited by: Christopher Brooks TO PTOLEMY II Authors: Shuvra S. Bhattacharyya Christopher Brooks Elaine Cheong John Davis, II Mudit Goel of Electrical Engineering and Computer Sciences University of California at Berkeley http://ptolemy
PTOLEMY II HETEROGENEOUS CONCURRENT MODELING AND DESIGN IN JAVA Edited by: Christopher Hylands of California at Berkeley http://ptolemy.eecs.berkeley.edu Document Version 2.0.1 for use with Ptolemy II 2 Concurrent Modeling and Design Contents Part 1: Using Ptolemy II 1. Introduction 1-1 1.1.Modeling and Design
Hybinette, Maria
PTOLEMY II HETEROGENEOUS CONCURRENT MODELING AND DESIGN IN JAVA Edited by: Christopher Brooks, Edward A. Lee, Xiaojun Liu, Steve Neuendorffer, Yang Zhao, Haiyang Zheng VOLUME 1: INTRODUCTION of the University of California. All rights reserved. "Java" is a registered trademark of Sun Microsystems. #12
Physiological heterogeneity in biofilms
Michael J. Franklin; Philip S. Stewart
Biofilms contain bacterial cells that are in a wide range of physiological states. Within a biofilm population, cells with diverse genotypes and phenotypes that express distinct metabolic pathways, stress responses and other specific biological activities are juxtaposed. The mechanisms that contribute to this genetic and physiological heterogeneity include microscale chemical gradients, adaptation to local environmental conditions, stochastic gene expression and
Dickey, P.A.
An overview of geological concepts and reservoir engineering practices as they apply to the field of development (production) geology is presented. The author touches on nearly every aspect of the field in the 21 chapters of the book. He summarizes the basic depositional origin, sedimentary characteristics, and petrology of hydrocarbon-bearing rocks. He discusses physical properties, origin, and migration of subsurface oil and gas, oil field water, and their behavior, including subsurface pressures and fluid mechanics. Also covered are various methods of estimating reserves, the major tools of the trade and their limitations, and case histories.
Geologic Maps and Structures Name ______________________________ Geology 100 Harbor section
Harbor, David
in 3-D and to develop some facility in interpreting the nature of geologic structures from geologic maps and geologic cross sections. A big part of this task is developing a skill for thinking in 3-D shows the rocks that occur at the surface (or just below the soil) and is usually printed on top
Exploiting heterogeneity in sensor networks
Mark D. Yarvis; Nandakishore Kushalnagar; Harkirat Singh; Anand Rangarajan; York Liu; Suresh Singh
The presence of heterogeneous nodes (i.e., nodes with an enhanced energy capacity or communication capability) in a sensor network is known to increase network reliability and lifetime. However, questions of where, how many, and what types of heterogeneous resources to deploy remain largely unexplored. We focus on energy and link heterogeneity in ad hoc sensor net- works and consider resource-aware
NASA Technical Reports Server (NTRS)
A wide variety of topics on planetary geology are presented. Subjects include stratigraphy and geomorphology of Copernicus, the Mamers valle region, and other selected regions of Mars and the Moon. Crater density and distribution are discussed for Callisto and the lunar surface. Spectroscopic analysis is described for Europa and Ganymede.
Restricted availability. Major Attributes: Polygons described by geologic type codes & descriptions. May be incorporated into maps at the state/county/basin scale. Probably too coarse for use at the site scale. Scale: 1:500:000. Extent: Idaho. Projection: Albers. Source: ...
NSDL National Science Digital Library
Louis J. Maher
This site is a collection of aerial images of US geological features. Detailed 2000-pixel-wide JPEG versions of these photos (averaging 1MB in size and suitable for video projection or for slides) can be down-loaded from an FTP site. There are also text captions for the photographs.
J. P. Penny; S. J. Reynolds
Seven years in the making, the 35 papers in this volume summarize the stratigraphic, structural, and tectonic evolution of Arizona from Precambrian through Quaternary time. Intended as a compendium of current knowledge of Arizona geology, the papers synthesize previous work with new data, ideas, and concepts as well as identifying unresolved problems for future research. Emphasis is placed on the
ERIC Educational Resources Information Center
Madison Public Schools, WI.
Included are a teacher's guidebook and two filmstrips, "Geology of Wisconsin," and associated materials. The following are described: outline of objectives; suggested use of the filmstrips and guidebook; outline of the filmstrip content; four pages of illustrations suitable for duplication; a test for each filmstrip; and a list of additionalģ
V. A. Vakhrameyev
The geological history of the Jurassic period shows that the most abrupt change in physiogeographical, and particularly in climatic, conditions occured not at its lower or upper limit but at the boundary between the middle and late epochs. This is shown especially clearly by a study of the lacustral and continental sediments which form such a significant feature of the
Geological and Inorganic Materials.
ERIC Educational Resources Information Center
Jackson, L. L.; And Others
Presents a review focusing on techniques and their application to the analysis of geological and inorganic materials that offer significant changes to research and routine work. Covers geostandards, spectroscopy, plasmas, microbeam techniques, synchrotron X-ray methods, nuclear activation methods, chromatography, and electroanalytical methods.ģ
Dinosaur Paleobiology Geology 331
Kammer, Thomas
Dinosaur Paleobiology Geology 331 Paleontology #12;Dinosaurs are popular with the public #12;Jack Horner, Montana State Univ. #12;Field Work in Montana #12;A dinosaur "drumstick" in its field jacket. #12;Abundant vascular canals in dinosaur bone support the warm- blooded theory #12;Thin section of dinosaur
Geological impacts on nutrition
Technology Transfer Automated Retrieval System (TEKTRAN)
This chapter reviews the nutritional roles of mineral elements, as part of a volume on health implications of geology. The chapter addresses the absorption and post-absorptive utilization of the nutritionally essential minerals, including their physiological functions and quantitative requirements....
ERIC Educational Resources Information Center
Madison Public Schools, WI.
This publication is a teacher's resource and guidebook for the presentation of the three filmstrips in the "Glacial Geology of Wisconsin" series. The first filmstrip is subtitled, "Evidence of the Glaciers," the second "How the Glaciers Reshaped the Landscape," and the third "Fossils of the Ice Age." Included are a list of objectives, an outlineģ
Reidel, Steve; Chamness, Mickie A.
This appendix provides a detailed description of geology under the Central Plateau of the Hanford Site, emphasizing the areas around tank farms. It is to be published by client CH2M HILL Hanford Group, Inc., as part of a larger, multi-contractor technical report.
American Geological Institute Homepage
NSDL National Science Digital Library
This is the homepage of the American Geological Institute (AGI). Visitors can access information about geoscience education, public policy, environmental geoscience, careers in geoscience, publications, news articles, and events. Materials presented here include databases, curriculum materials, legislation and appropriations information, and an image bank.
NSDL National Science Digital Library
Allen Collins
This University of California site provides an interactive geologic time scale to explore the history of the Earth. Beginning in the Precambrian Eon (4.6 million years ago) and ending today (Holocene Epoch), each Epoch, Period, Era, and Eon are covered. Information provided includes ancient life, dates, descriptions of major events, localities, tectonics, and stratigraphy. Links to additional resources are also available.
K. L. Burns
Geological events, such as emplacement of granite or growth of slaty cleavage, may be ordered into a sequence by two methods. One is to assign each event a place in a time scale, such as years before the present, which amounts to assigning events an age designation from the set of real numbers. In ordering such a list, the algebra
Structural-geological models of the Ketzin CO2 storage pilot site used for site evaluation, dynamic reservoir simulations, and monitoring purposes
NASA Astrophysics Data System (ADS)
Norden, Ben; Kling, Christian; Frykman, Peter; Krawczyk, Charlotte M.
The saline aquifer of the Stuttgart Formation (Upper Triassic) is used for a carbon dioxide (CO2) storage research project at Ketzin, about 25 km west of Berlin (Germany). The structural and lithological site characterization relies on a comprehensive data set, consisting of former exploration data (hydrocarbon and natural gas storage exploration) and of the recent exploration, production, and monitoring data acquired at the CO2 pilot site. The quality of the data in terms of resolution and documentation is variable, covering also different scales. We present an overview of the structural and lithological characterization of the Ketzin CO2 pilot site that is based on the evolution of the geological models prepared for storage site development and site operation. In order to be able to assess risk elements, especially in the early regulatory and permitting stages of the project, the geological model building concentrated on two scales: Firstly, the site scale (called geo-model, comprising the reservoir and its overburden), and, secondly, the reservoir scale, using a higher resolution. The reservoir scale was applied to the target horizon of the CO2 storage (the Triassic Stuttgart Formation) and the Quaternary to Tertiary layers, presenting the near-surface groundwater system. The first geo-models illustrate the geological setting of the Ketzin site as a part of a salt-anticlinal structure based on seismic legacy data. These models were used to give first estimates on the deep natural groundwater flow and to establish pre-drilling profiles, but could not give reliable information on the existence and distribution of faults. Nevertheless, the estimated bed boundaries of the Stuttgart Formation served as an input for the construction of the first reservoir models of the Stuttgart Formation which were used to illustrate the expected variability and heterogeneity in rock properties. The target formation is lithologically very heterogeneous, reflecting a complex fluviatile facies distribution pattern: sandy rocks of the channel facies are embedded in muddy rocks of the floodplain facies. The facies distribution and its hydraulic parameterization were modeled using a stochastic approach. After the processing of the 3D seismic data acquired in 2005, and the drilling of three boreholes in Ketzin in 2007, the need of a re-interpretation of the geological models was given to account for the higher resolution of the new input data. In the revised models it was possible to map the main faults at the site with good accuracy. In addition, seismic facies analysis was performed by applying a spectral decomposition technique to the 3D seismic data. Thereby, subsurface features could be identified, which may indicate to some degree the distribution of the fluvial channel facies of the reservoir formation. This data was then also used to guide the stochastic reservoir modeling of the Stuttgart Formation. In addition, the interpretation of seismic CO2 monitoring data gives further evidence of the mean CO2 distribution in the subsurface and could partly guide the structural interpretation. This data enables a local deterministic refinement of the stochastic reservoir model. Finally, another well drilled into the storage formation in 2012 serves as an additional input to the geological models.
Geology Fieldnotes: Noatak National Monument
NSDL National Science Digital Library
This feature discusses the geologic framework, history, tectonic setting, and soil and rock types of Northwest Alaska, as seen in the Noatak National Monument. Links are also provided to maps, visitor information, and to geological and conservation organizations.
Geology of California. Second Edition
Norris, R.M.; Webb, R.W.
Two introductory chapters familiarize readers with basic geologic concepts. The following chapters describe the geology of each of California's 11 geomorphic provinces; the San Andreas fault and offshore geology are discussed in two separate chapters. Four appendices acquaint readers with technical words and terms, common minerals and rocks in California, geologic time, and geologic theories that pertain to California. During the 1960s evidence collected from the east Pacific sea floor off the western coast of North America gave scientists supporting data for Alfred Wegener's 1910 theory of continental drift. In addition to the confirmation of continental drift, since the 1960s scientists have discovered paleomagnetism, sea-floor spreading, exotic and suspect terranes, and polar wandering. These important concepts have had far reaching effects about how we understand the geology of California and how this region has evolved through geologic time. Improved investigative procedures enable earth scientists to comprehend previously puzzling aspects of California's geology.
Geology of the Colorado Plateau
NSDL National Science Digital Library
Colorado Plateau Field Institute
This web page provides a general description of the geology of the Colorado Plateau. Topics include information about the various geologic environments and processes active during the Precambrian and the Paleozoic, Mesozoic and Cenozoic Eras.
Large epidemic thresholds emerge in heterogeneous networks of heterogeneous nodes
Yang, Hui; Gross, Thilo
One of the famous results of network science states that networks with heterogeneous connectivity are more susceptible to epidemic spreading than their more homogeneous counterparts. In particular, in networks of identical nodes it has been shown that heterogeneity can lower the epidemic threshold at which epidemics can invade the system. Network heterogeneity can thus allow diseases with lower transmission probabilities to persist and spread. Here, we point out that for real world applications, this result should not be regarded independently of the intra-individual heterogeneity between people. Our results show that, if heterogeneity among people is taken into account, networks that are more heterogeneous in connectivity can be more resistant to epidemic spreading. We study a susceptible-infected-susceptible model with adaptive disease avoidance. Results from this model suggest that this reversal of the effect of network heterogeneity is likely to occur in populations in which the individuals are aware of t...
The Geological Society Web Shop
NSDL National Science Digital Library
The Geological Society has launched an on-line bookshop, through which both Fellows and non-Fellows of the Society can purchase Geological Society books. Visitors can select books listed under the following headings: Tectonics, Economic Geology, Environmental, Petrology, Stratigraphy, Marine Studies, and Geophysics. The Geological Society Web Shop can be browsed or searched by keyword. Information on opening an account and purchasing books is available at the site.
Use of porphyroblast-matrix relationships to solve a complex polyphase geologic history in Middle Proterozoic rocks of central New Mexico
A. G. Thompson; K. E. Karlstrom
Porphyroblast-matrix textural relationships are often ambiguous and, used in isolation, can lead to conflicting interpretations of the geologic history of an area because deformation and metamorphism are generally heterogeneous in both space and time. This is true in Proterozoic rocks in southwestern North America where the debate about an orogenic versus an orogenic Middle Proterozoic geologic history continues. For example,
Structural Geology: Deformation of Rocks
Kammer, Thomas
. Ę Rocks deform when applied stress exceeds rock strength. Deformation may be ductile flow or brittleStructural Geology: Deformation of Rocks Geology 200 Geology for Environmental Scientists #12;Major of Maine #12;Chevron folds in brittle rocks. An example of angle parallel folding. #12;Angle parallel
The Second Flowering of Geology.
ERIC Educational Resources Information Center
Cloud, Preston
Discusses two "golden" ages in geological investigations/inquiry. The first, extending from the late eighteenth century through the early nineteenth century, established geology as a science based on naturalistic principles. The second, beginning after World War II, is characterized by advances in geological specialities and explanations based onģ
Ordering Geologic Events and Interpreting Geologic History: The Grand Canyon
NSDL National Science Digital Library
Jennifer Wenner
This activity is designed to help students recognize the connections among things like rock identification and map reading with the "story" that these things can tell us in terms of geologic history. Students have already learned about using observation to identify rocks and the principles of interpreting geologic cross-sections. The activity gives students practice in rock ID, topo map reading, geologic map reading and the aspects of geologic time. Students work with rock samples and a geologic map of the Grand Canyon to interpret a history for the area.
USGS National Geologic Map Database: State-wide Geologic Maps
NSDL National Science Digital Library
This search tool provides descriptions and availability information for geologic maps of the 50 States, the District of Columbia, and Puerto Rico. These geologic maps are published by a variety of organizations, including State geologic agencies, the U.S. Geological Survey (USGS), universities, and private companies. Title, date, scale, publisher, series (where applicable), and basic ordering information is provided for each map. A place name search and an advanced search using geologic themes, areas, publishers and other criteria allow for more specific queries to the database.
Geology Fieldnotes: Jewel Cave National Monument, South Dakota
NSDL National Science Digital Library
Jewel Cave National Monument feaures the third longest cave in the world; airflow within its passages indicates a vast area yet to be explored. Cave tours provide opportunities for viewing this pristine cave system and its wide variety of rock formations. Features include park geology information, maps, related links, and visitor information. The park geology section discusses the history of the park's discovery and exploration by cavers, and describes some of the remarkable rock formations found in the cave. The maps section includes a map of Jewel Cave National Monument and the surrounding area.
Geological environment of karst within chalk using airborne time domain electromagnetic data cross-interpreted with boreholes
NASA Astrophysics Data System (ADS)
Reninger, P.-A.; Martelet, G.; Lasseur, E.; Beccaletto, L.; Deparis, J.; Perrin, J.; Chen, Y.
The ability of airborne Time Domain ElectroMagnetic (TDEM) to image plurikilometric chalk heterogeneities and its implications for the development of a karstic system is addressed in this study. A heliborne TDEM survey was conducted around Courtenay (France) over the Paris Basin Upper Cretaceous chalk. This aquifer is known as a highly weathered and karstified horizon both strongly modify chalk petrophysical properties. Numerous boreholes and one recently reprocessed seismic line were used in order to strengthen TDEM interpretations. We performed cross statistics between boreholes and the resistivity model. This allowed defining empirical resistivity ranges corresponding to the main geological formations within the area. We were therefore able to map large scale heterogeneities in the chalk over the study area. First, the TDEM method highlighted probable weathering corridors in the chalk, related to the tectonic activity, consistent with faults previously interpreted in the seismics at deeper levels. Second, it was possible to image a large scale undulating geometry in the chalk with a SW-NE orientation, this direction is consistent throughout the Paris Basin, and well defined on the cliffs of Normandy (Channel coast, north of France). This geometry has revealed two separate chalk deposits C1 and C2 in Courtenay area: C1 is more resistive than C2. The resistivity model has then been compared to piezometric measurements acquired as part of previous hydrological studies. The karstic drainage appears to be developed within C1 chalk deposit and most of the piezometric domes seem to be associated to intermediate resistivity zones in C1, interpreted as weathered. According to the results obtained from this study, we were able to suggest a geological framework for the development of Courtenay karstic system.
Flow and transport in unsaturated fractured rock: effects of multiscale heterogeneity of
Zhou, Quanlin
to represent complex heterogeneity at two different scales: (1) layer scale corresponding to geologic layering the travel time of a conservative tracer from the source (repository) horizon in the unsaturated zone, especially at the early arrival time of tracer mass. However, the effect is not significant at the later time
Geologic Maps and Geologic Structures: A Texas Example
NSDL National Science Digital Library
Roger Steinberg
This Historical Geology lab exercise is an accompaniment to lab class instruction about geologic structures (folding and faulting) and geologic maps. It also serves as an excellent introduction to the Geology of the state of Texas. "Coloring" geologic maps, an important part of the exercise, may seem like a very elementary learning technique. But this lab engages students actively, and since the subject is often already somewhat familiar to them, emphasizing both the geology and geography of Texas, students receive it enthusiastically. This activity could be adapted to other regions, since most states have color 8 1/2 by 11 geologic maps available. A color map could be scanned and modified in Photoshop to create a simplified black and white version as was done in the assignment handout.
Heterogeneous HPC Environments
Marco Vanneschi
Directions of software technologies for innovative HPC environments are discussed according to the industrial user requirements\\u000a for heterogeneous multidisciplinary applications, performance portability, rapid prototyping and software reuse, integration\\u000a and interoperability of standard tools. The various issues are demonstrated with reference to the PQE2000 project and its\\u000a programming environment SkIE (Skeleton-based Integrated Environment). Modules developed by a variety of standard languages
ŁPTOLEMY II Ł HETEROGENEOUS CONCURRENT MODELING AND DESIGN IN JAVA John Davis, II Ron Galicia Mudit University of California at Berkeley http://ptolemy.eecs.berkeley.edu Document Version 0.1.1 February 12 Syntaxes 1Ł6 1.5. Ptolemy II 1Ł7 1.5.1. Package Structure 1Ł7 1.5.2. Overview of Key Classes 1Ł9 1
-PTOLEMY II - HETEROGENEOUS CONCURRENT MODELING AND DESIGN IN JAVA John Davis, II Ron Galicia Mudit University of California at Berkeley http://ptolemy.eecs.berkeley.edu Document Version 0.1.1 February 12.2.8. Timed CSP and Timed PN 1-5 1.3.Choosing Models of Computation 1-6 1.4.Visual Syntaxes 1-6 1.5.Ptolemy II
Surface heterogeneity of minerals
Frķdķric Villiķras; Laurent J. Michot; Frķdķrique Bardot; Manuel Chamerois; Cķline Eypert-Blaison; MichĶle Franńois; Gilles Gķrard; Jean-Maurice Cases
The precise study of adsorption mechanisms at solid¢liquid interfaces requires a good analysis of the surface heterogeneity of the studied solids. For that purpose, molecular probe technique is one of the most powerful, especially at solid¢gas interfaces. Indeed, low-pressure gas adsorption coupled to modelling of derivative adsorption isotherms as a function of logarithm of pressure allows to study qualitatively and
Nighttime chemical evolution of aerosol and trace gases in a power plant plume: Implications for secondary organic nitrate and organosulfate aerosol formation, NO3 radical chemistry, and N2O5 heterogeneous hydrolysis
Zaveri, R.A.; Kleinman, L.; Berkowitz, C. M.; Brechtel, F. J.; Gilles, M. K.; Hubbe, J. M.; Jayne, J. T.; Laskin, A.; Madronich, S.; Onasch, T. B.; Pekour, M. S.; Springston, S. R.; Thornton, J. A.; Tivanski, A. V.; Worsnop, D. R.
Nighttime chemical evolution of aerosol and trace gases in a coal-fired power plant plume was monitored with the Department of Energy Grumman Gulfstream-1 aircraft during the 2002 New England Air Quality Study field campaign. Quasi-Lagrangian sampling in the plume at increasing downwind distances and processing times was guided by a constant-volume balloon that was released near the power plant at sunset. While no evidence of fly ash particles was found, concentrations of particulate organics, sulfate, and nitrate were higher in the plume than in the background air. The enhanced sulfate concentrations were attributed to direct emissions of gaseous H{sub 2}SO{sub 4}, some of which had formed new particles as evidenced by enhanced concentrations of nucleation-mode particles in the plume. The aerosol species were internally mixed and the particles were acidic, suggesting that particulate nitrate was in the form of organic nitrate. The enhanced particulate organic and nitrate masses in the plume were inferred as secondary organic aerosol, which was possibly formed from NO{sub 3} radical-initiated oxidation of isoprene and other trace organic gases in the presence of acidic sulfate particles. Microspectroscopic analysis of particle samples suggested that some sulfate was in the form of organosulfates. Microspectroscopy also revealed the presence of sp{sup 2} hybridized C = C bonds, which decreased with increasing processing time in the plume, possibly because of heterogeneous chemistry on particulate organics. Constrained plume modeling analysis of the aircraft and tetroon observations showed that heterogeneous hydrolysis of N{sub 2}O{sub 5} was negligibly slow. These results have significant implications for several issues related to the impacts of power plant emissions on air quality and climate.
Characterization of oil and gas reservoir heterogeneity
Tyler, N.; Barton, M.D.; Bebout, D.G.; Fisher, R.S.; Grigsby, J.D.; Guevara, E.; Holtz, M.; Kerans, C.; Nance, H.S.; Levey, R.A.
Research described In this report addresses the internal architecture of two specific reservoir types: restricted-platform carbonates and fluvial-deltaic sandstones. Together, these two reservoir types contain more than two-thirds of the unrecovered mobile oil remaining ill Texas. The approach followed in this study was to develop a strong understanding of the styles of heterogeneity of these reservoir types based on a detailed outcrop description and a translation of these findings into optimized recovery strategies in select subsurface analogs. Research targeted Grayburg Formation restricted-platform carbonate outcrops along the Algerita Escarpment and In Stone Canyon In southeastern New Mexico and Ferron deltaic sandstones in central Utah as analogs for the North Foster (Grayburg) and Lake Creek (Wilcox) units, respectively. In both settings, sequence-stratigraphic style profoundly influenced between-well architectural fabric and permeability structure. It is concluded that reservoirs of different depositional origins can therefore be categorized Into a heterogeneity matrix'' based on varying intensity of vertical and lateral heterogeneity. The utility of the matrix is that it allows prediction of the nature and location of remaining mobile oil. Highly stratified reservoirs such as the Grayburg, for example, will contain a large proportion of vertically bypassed oil; thus, an appropriate recovery strategy will be waterflood optimization and profile modification. Laterally heterogeneous reservoirs such as deltaic distributary systems would benefit from targeted infill drilling (possibly with horizontal wells) and improved areal sweep efficiency. Potential for advanced recovery of remaining mobile oil through heterogeneity-based advanced secondary recovery strategies In Texas is projected to be an Incremental 16 Bbbl. In the Lower 48 States this target may be as much as 45 Bbbl at low to moderate oil prices over the near- to mid-term.
Internet-based information system of digital geological data providing
NASA Astrophysics Data System (ADS)
Yuon, Egor; Soukhanov, Mikhail; Markov, Kirill
One of the Russian Federal ?gency of mineral resources problems is to provide the geological information which was delivered during the field operation for the means of federal budget. This information should be present in the current, conditional form. Before, the leading way of presenting geological information were paper geological maps, slices, borehole diagrams reports etc. Technologies of database construction, including distributed databases, technologies of construction of distributed information-analytical systems and Internet-technologies are intensively developing nowadays. Most of geological organizations create their own information systems without any possibility of integration into other systems of the same orientation. In 2012, specialists of VNIIgeosystem together with specialists of VSEGEI started the large project - creating the system of providing digital geological materials with using modern and perspective internet-technologies. The system is based on the web-server and the set of special programs, which allows users to efficiently get rasterized and vectorised geological materials. These materials are: geological maps of scale 1:1M, geological maps of scale 1:200 000 and 1:2 500 000, the fragments of seamless geological 1:1M maps, structural zoning maps inside the seamless fragments, the legends for State geological maps 1:200 000 and 1:1 000 000, full author's set of maps and also current materials for international projects ½Atlas of geological maps for Circumpolar Arctic scale 1:5 000 000╗ and ½Atlas of Geologic maps of central Asia and adjacent areas scale 1:2 500 000╗. The most interesting and functional block of the system - is the block of providing structured and well-formalized geological vector materials, based on Gosgeolkart database (NGKIS), managed by Oracle and the Internet-access is supported by web-subsystem NGKIS, which is currently based on MGS-Framework platform, developed by VNIIgeosystem. One of the leading elements is the web-service, which realizes the interaction of all parts of the system and controls whole the way of the request from the user to the database and back, adopted to the GeoSciML and EarthResourceML view. The experience of creation the Internet-based information system of digital geological data providing, and also previous works, including the developing of web-service of NGKIS-system, allows to tell, that technological realization of presenting Russian geological-cartographical data with using of international standards is possible. While realizing, it could be some difficulties, associated with geological material depth. Russian informational geological model is more deep and wide, than foreign. This means the main problem of using international standards and formats: Russian geological data presentation is possible only with decreasing the data detalisation. But, such a problem becomes not very important, if the service publishes also Russian vocabularies, not associated with international vocabularies. In this case, the international format could be the interchange format to change data between Russian users. The integration into the international projects reaches developing of the correlation schemes between Russian and foreign classificators and vocabularies.
NASA Astrophysics Data System (ADS)
Jaumann, R.
Observations from the Dawn spacecraft [1] enable the derivation of the asteroid 4Vesta's shape, facilitate mapping of the surface geology, and provide the first evidence for interpreting Vesta's geological evolution. Science data were acquired during the approach to Vesta, a circular polar (Survey) orbit at an altitude of 2700 km providing ~ 230 m/pix camera scale, and during a circular high-altitude mapping orbit (HAMO) at 700 km altitude with a camera scale of ~ 65 m/pixel. Currently Dawn is orbiting Vesta in a low-altitude mapping orbit (LAMO) at 210 km altitude, yielding a global image coverage of ~20 m/pixel at the time of EGU [2,3,4,5]. Geomorphology and distribution of surface features provide evidence for impact cratering, tectonic activity, and regolith and probable volcanic processes. Craters with dark rays, bright rays, and dark rim streaks have been observed, suggesting buried stratigraphy. The largest fresh craters retain a simple bowl-shaped morphology, with depth/diameter ratios roughly comparable to lunar values. The largest crater Rheasilvia, an ~500 km diameter depression at the south pole, includes an incomplete inward facing cuspate scarp and a large central mound surrounded by unusual complex arcuate ridge and groove patterns, and overlies an older ~400 km wide basin. A set of large equatorial troughs is related to these south polar structures. Vesta exhibits rugged topography ranging from -22 km to +19 km relative to a best fit ellipsoidal shape. Vesta's topography has a much greater range in elevation relative to its radius (15%) than do the Moon and Mars (1%) or the Earth (0.3%), but less than highly battered smaller asteroids like Lutetia (40%). This also identifies Vesta as a transitional body between asteroids and planets. The surface of Vesta exhibits very steep topographic slopes that are near the angle of repose. Impacts onto these steep surfaces, followed by slope failure, make resurfacing - due to impacts and their associated gravitational forces and seismic activity - an important geologic process on Vesta that significantly alters the morphology of geologic features and adds to the complexity of its geologic history. In general, Vesta's geology is more like the Moon and rocky planets than other asteroids.
A geological investigation of the Taurus-Littrow Valley. [characteristics of Apollo 17 flight lunar landing site
NASA Technical Reports Server (NTRS)
Schmitt, H. H.; Cernan, E. A.
The geological characteristics of the Taurus-Littrow region in the mountainous southeastern ring of the great plain of the Mare Serenitatis are presented. The major geologically defined units within the valley and the mountains surrounding it were examined during the Apollo 17 mission. The data obtained during the geological analysis are presented. Photographs of the significant formations are included. The specific nature of the rock formations and the stratigraphy of the area are discussed.
Spreadsheet log analysis in subsurface geology
Doveton, J.H.
Most of the direct knowledge of the geology of the subsurface is gained from the examination of core and drill-cuttings recovered from boreholes drilled by the petroleum and water industries. Wireline logs run in these same boreholes generally have been restricted to tasks of lithostratigraphic correlation and thee location of hydrocarbon pay zones. However, the range of petrophysical measurements has expanded markedly in recent years, so that log traces now can be transformed to estimates of rock composition. Increasingly, logs are available in a digital format that can be read easily by a desktop computer and processed by simple spreadsheet software methods. Taken together, these developments offer accessible tools for new insights into subsurface geology that complement the traditional, but limited, sources of core and cutting observations.
A review of applications to constrain pumping test responses to improve on geological description and uncertainty
Rajagopal Raghavan
This review examines the single-phase flow of fluids to wells in heterogeneous porous media and explores procedures to evaluate pumping test or pressure-response curves. This paper examines how these curves may be used to improve descriptions of reservoir properties obtained from geology, geophysics, core analysis, outcrop measurements, and rock physics. We begin our discussion with a summary of the classical
Geological and operational summary, North Aleutian Shelf Coast No. 1 well, Bering Sea, Alaska. Final report
Turner, R.F.
Discusses the first continental offshore stratigraphic test well drilled in the North Aleutian Basin Planning Area, Bering Sea, Alaska. The well was drilled to determine the hydrocarbon potential of the area. The report covers drilling operations; lithology and core data; velocity analysis; geologic setting and tectonic framework; seismic stratigraphy; well-log interpretation and lithostratigraphy; paleontology and biostratigraphy; geothermal gradient; organic geochemistry; abnormal formation pressure; geologic hazards and shallow geology; and environmental considerations.