个旧锡矿区鲕状黄铁矿和胶状结构黄铁矿中锡的分布及其成因意义  

DISTRIBUTION AND GENETIC SIGNIFICANCE OF Sn IN OOLITIC PYRITE AND COLLOIDALLY STRUCTURED PYRITE FROM GEJIU TIN DEPOSITS

作　　者：张欢[1] 高振敏[1] 马德云[1] 陶琰[1] 刘鸿 

机构地区：[1]中国科学院地球化学研究所矿床地球化学开放研究实验室 [2]贵州省晴隆锑矿,贵州晴隆561400

出　　处：《矿物学报》2004年第1期87-91,共5页Acta Mineralogica Sinica

基　　金：云南省院省校合作项目(编号:2000YK-04)

摘　　要：通过电子探针背散射图象扫描分析,发现鲕状黄铁矿和胶状结构黄铁矿中存在锡石包体,大小2～5μm。对无锡石包体的区域进行电子探针定量分析,测出鲕状黄铁矿中w(Sn)最高可达0 23%,胶状磁黄铁矿中最高可达0 06%。结合ICP MS等离子质谱分析结果,认为鲕状黄铁矿和胶状结构黄铁矿中Sn的分布有两种形式:一种是以锡石(SnO2)包体形式存在;另一种是分散在黄铁矿中的Sn,可能以类质同像形式存在。锡石包体的存在暗示着海底喷流时可形成锡的独立矿物,鲕状黄铁矿和胶状结构黄铁矿中含锡,表明海底喷流形成硫化物矿物的同时携带了Sn,在后期花岗岩热液叠加改造过程中可起到Sn的矿源层的作用。Through electron probe and ICP-MS analyses, we found that Sn may account for 0.23% in oolitic pyrite and (0.06)% in colloidally structured pyrite. There are two forms of occurrence of Sn in oolitic pyrite and olloidally structured pyrite: SnO_2 enclaves and isomorphs. It is suggested that there is abundant Sn involved in hot-water deposition and at that time Sn may be the mineral form of SnO_2. All this indicates that hot-water may provide the mineralizing element Sn for the formation of one of the ore beds, which may be reworked by later granitic hydrothermal solutions.

关 键 词：锡矿 黄铁矿 类质同像 海底喷流 矿源层 

分 类 号：P618.44[天文地球—矿床学]