Fossil land plants are recorded in terrestrial, lacustrine, fluvial and nearshore marine sediments. Drainage basins are the principal hydrologic unit considered in fluvial geomorphology. Tufa forms either in fluvial channels or in lacustrine environments. Finally there is the modern rift unit of fluvial, glacial, and deltaic sediments. The greatest effects were observed in areas underlain by loose Holocene aeolian and fluvial sands. Degraded impact structures record variations in volcanic, fluvial, and aeolian activity. Each of the individual sequences contains sediments deposited under fluvial, shoreline and shallow marine conditions. No evidence of fluvial or aeolian erosion is observed in this region. These contain facies that are affected by tide and wave fluvial processes. Geologically ancient floodplains are often represented in the landscape by fluvial terraces. This probably stems from poor visibility in fluvial and estuarine environments. A cirque may also be a similarly shaped landform arising from fluvial erosion. The gradual transition from glaciated to fluvial valley can be clearly observed. There is evidence of erosion at the base of the rocks, indicating possible fluvial activity. Conglomerates deposited in fluvial environments are typically well rounded and well sorted.