{'fraction_non_alphanumeric': 0.03555219364599092, 'fraction_numerical': 0.00869894099848714, 'mean_word_length': 5.482843137254902, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Comparative geology and geochemistry of sedimentary-rock-hosted (Carlin Type) gold deposits in the People's Republic of China and in Nevada, USA

Sedimentary rock-hosted (Carlin-type) gold deposits have been considered economically significant and geologically distinct since the early 1960's. Similar deposits have been discovered in P.R. China, Australia, Dominican Republic, Spain, Russia, Malaysia, Philippines, Yugoslavia, and Greece, in addition to the Great Basin, US. This report contains data on 113 sedimentary rock-hosted gold deposits (prospects) in southwest and central People’s Republic of China. Of these, at least 19 deposits are of substantial tonnage, making P.R. China the second leading country to the United States in exploiting these deposits. A new Proterozoic age sedimentary rock-hosted gold deposit in northeastern P.R. China also is described. Chinese sedimentary rock-hosted deposits are mainly located along the margins of the Precambrian Yangtz craton. Their distribution is controlled by regional rifts, whereas secondary structures, such as shortaxial anticlines, high-angle faults, stratabound breccia bodies, and unconformity surfaces, also are favorable host structures. The deposits are found in sedimentary formations of Paleozoic to Cenozoic age, and local deposits in the northeastern part of China are hosted in Proterozoic age rocks. Impure limestone, siltstone, and argillite are the host rocks for ore. Alteration types are silicification, decalcification, argillization, carbonization, and locally albitization. Igneous intrusions usually are not present near most Chinese deposits, except for local lamprophyre and silicic dikes. 1 Gold is disseminated in sedimentary rock-hosted gold deposits. The main opaque minerals include gold, electrum, pyrite, arsenopyrite, stibnite, orpiment, realgar, and cinnabar; gangue minerals are quartz, barite, organic carbon, carbonate and clay minerals, and local albite. Elements associated with gold in Nevada deposits, As, Sb, and Hg, also are closely associated with the Chinese deposits, but U deposits also are associated with some gold deposits in China, and platinum group elements (PGEs) also locally are enriched to economic levels in some of these deposits. Low salinity fluid inclusions (3 to 9 wt. percent NaCl equivalent) and limited stable isotope data suggest possible multiple sources of metallogenic fluids in the Chinese deposits, similar to those in Nevada. Trapping temperatures vary from 165 to 290 °C, and pressures of formation range from 52 to 560 bars, indicating that Chinese Carlin-type gold deposits formed at or below the epithermal