云南个旧新山层状透辉石岩地质地球化学特征与成因探讨

新山层状、似层状透辉石岩产于新山岩体顶部碳酸盐岩地层层间，颜色较浅，呈浅绿色。其主要矿物为次透辉石，含量在50％以上，其次为钙长石，且矿物粒度小，呈间粒间隐结构。而发育在矿区花岗岩体与碳酸盐岩地层接触带的透辉石夕卡岩中主要矿物为钙铁辉石，含量在65％以上，其次为透闪石、石榴石和硅灰石等，矿物粒度较粗，呈显晶粒状结构。新山层状、似层状透辉石岩具有高Mg、Ti、P，富集sr和大离子亲石元素（Rh、tn、u），相对亏损Ba、K等特征；稀土分配模式为右倾型，具有较小的Eu负异常（0．40—0．61）。整体上具有与矿区碱性玄武岩相似的微量元素和稀土元素特征，明显有别于新山花岗岩及新山典型的透辉石夕卡岩。通过地质、岩石学及地球化学研究，认为新山层状、似层状透辉石岩原岩很可能就是印支期碱性玄武岩，即在热卤水体系中，拉张裂谷环境下喷发的碱性玄武岩经热水交代蚀变形成。

Geology,Geochemistry and Genesis of Xinshan stratiform Diopside rocks in Gejiu,Yunnan

Most of Xinshan bedded and Quasi-bedded diopside rocks,with light green color,present in the interlayer of carbonate formation at the top of Xinshan granites.The most abundant mineral of the diopside rocks is sahlite,whose content is over 50%.The second abundant mineral is anorthite,whose granularity are small and with cryptocrystalline texture.However,the main mineral of typical diopside skarn in this mine area in the contact zone between Xinshan granites and carbonate formation is hedenbergite,with conten...