滇黔交界地区峨眉山玄武岩铜矿的PGE及微量元素特征

PGE and trace element characteristics of copper mineralization in Emeishan basalts of Yunnan-Guizhou border area

为了进一步探讨玄武岩铜矿的成因,文章对滇黔交界地区玄武岩铜矿石的铜、铂族元素及其他微量元素的地球化学特征进行了研究。结果表明:与铜矿化关系密切的有机质对铜的初始富集作用不明显,铜矿化是后生热液成因的,进一步支持了玄武岩为铜矿化的矿源岩、沥青及碳质等有机质的存在只是为自然铜沉淀提供了条件的认识。而且,铜矿石的低U、Th含量为该类铜矿石的铅是正常铅提供了合理的解释。

In order to understand the genesis of the copper mineralization in the Emeishan basalts, the authors studied characteristics of Cu, PGE and other trace elements in copper ores from the basalts in the Yunnan-Guizhou border area. Some conclusions have been drawn: ① There is no obvious enrichment of Cu in the original organic matter and the copper mineralization is mainly epigenetic, which further supports the conclusion that the basalt provided Cu for copper mineralization and the organic matter provided the reductive condition for the precipitation of native copper. ② The low Th and U content of the copper ores suggests that the Pb isotopic compositions of this type of ores are normal lead instead of radiogenic lead.