Sedimentary characteristics of Mg-rich carbonate formations and minerogenic fluids of magnesite and talc occurrences in early Proterozoic in eastern Liaoning Province, China  

作　　者：陈从喜 鲁安怀 蔡克勤 翟裕生 

机构地区：[1]School of Earth and Space Sciences, Peking University, Beijing 100871 China [2]China University of Geosciences (Beijing), Beijing 100083 China

出　　处：《Science China Chemistry》2002年第z1期84-92,共9页中国科学（化学英文版）

摘　　要：There are large to superlarge magnesite and talc deposits occurring in Mg-rich carbonate formations distributed in the early Proterozoic Dashiqiao Formation in eastern Liaoning Province, China. The discovery of the sedimentary gypsum, isotopic geochemistry of Δ18osmow, Δ13cpdb, Δ34svcdt and Sr/Ba ratio of carbonate, talc, quartz and gypsums with field investigation and sample analysis in laboratory demonstrate that the formation of magnesite and talc deposits is closely related to marine evaporates, which then underwent reworking of regional metamorphism and hydrothermal metasomatism. Metasomatic fluids originating from the paleoseawater played a controlling role in the formation of talc deposits.There are large to superlarge magnesite and talc deposits occurring in Mg-rich carbon- ate formations distributed in the early Proterozoic Dashiqiao Formation in eastern Liaoning Prov- ince, China. The discovery of the sedimentary gypsum, isotopic geochemistry of δ^(18)O_(SMOW), δ^(13)C_(PDB), δ^(34)S_(VCDT) and Sr/Ba ratio of carbonate, talc, quartz and gypsums with field investigation and sample analysis in laboratory demonstrate that the formation of magnesite and talc deposits is closely related to marine evaporates, which then underwent reworking of regional metamorphism and hydrothermal metasomatism. Metasomatic fluids originating from the paleoseawater played a controlling role in the formation of talc deposits.

关 键 词：magnesite  talc  minerogenic fluid  EASTERN LIAONING Province  early Proterozoic. 

分 类 号：P53[天文地球—古生物学与地层学]