东胜矿床稳定同位素地球化学特征及地质意义

东胜砂岩型铀矿的形成、改造及保矿是有机-无机流体共同作用的结果,其作用过程伴随众多可识别的后生蚀变标志.对这些流体作用产物的稳定同位素特征研究可以追朔流体作用的类型、特点和性质,从而为该矿床的成因及找矿提供理论依据.本文主要选择透镜状碳酸盐化及矿化层钙化木中方解石进行碳、氧同位素分析,含矿层砂岩中黄铁矿进行硫同位素测试.碳、氧同位素分析结果表明,透镜状碳酸盐化及钙化木的形成其碳质来源与油气等有机质流体作用有关;硫同位素数据分析表明,黄铁矿硫源具有生物细菌-煤质共同作用的特点;结合前人对碳酸盐氢氧同位素及流体物理化学参数等特征的研究,综合分析得出了东胜矿床的形成为由"大气降水-逸散油气-煤质有机酸-低温热液"混合流体作用结果的认识.

The geochemistry characteristics of the stable isotope in Dongsheng deposit and its geologic signification

The formation,transformation and preservation of Dongsheng sandstonetype uranium deposit is the combined action of the organic and inorganic fluid,in these processes there are a number of recognizable epigenetic alterated signs.Researches on the characteristics of stable isotopes in these fluid products could date from types,characteristics and nature of fluid,which provides a theoretical basis for deposit causes and mineral prospecting.This research main selects carbon and oxygen isotopes in calcite in calcified wood and sulfur isotopes in pyrite in sandstone.The carbon and oxygen isotopes analysis showes that the formation of lenticular carbonate and calcified wood and carbon source are relate to the fluid action of organic matter;Sulfur isotope analysis indicates that sulfur source has the characteristic between the biological bacteria and coal.According to the former researches on the carbonate hydrogen and oxygen isotope and fluid physical-chemical parameters,the paper presents an opinion that the formation of Dongsheng deposit is the result of combined fluid action by atmospheric precipitation-dissipation hydrocarbon-coal organic acid-low-temperature hydrothermal.