滇西马厂箐富碱侵入岩体形成机制研究  

Study on Forming Mechanism of Machangqing Alkaline-rich Intrusive Rock in Western Yunnan

作　　者：郭晓东[1] 李建文[1] 夏锐[1,2] 陈永福[1] 王梁[1,2] 王志华[1,2] 鹿青[1] 

机构地区：[1]武警黄金地质研究所,河北廊坊065000 [2]中国地质大学地球科学与资源学院,北京100083

出　　处：《地质论评》2014年第1期125-137,共13页Geological Review

基　　金：中国地质调查局地质调查工作项目(编号1212011121266;1212011220921);武警黄金指挥部专项基金(编号WHY11-08)的成果

摘　　要：马厂箐岩体属于滇西富碱侵入岩带上的一个典型代表,岩体中发现大量暗色微粒包体。对暗色微粒包体及其寄主岩进行系统岩石学、岩石化学和Sr、Nd、Pb同位素研究,认为马厂箐岩体为一岩浆混合成因岩体,形成于新生代陆壳加厚的构造背景下,暗色微粒包体来源于富集地幔岩浆,寄主岩花岗斑岩来源于大陆地壳的长英质岩浆,是幔源岩浆底侵作用诱发其上的陆壳岩石熔融所形成的混合岩浆上侵定位的结果。幔源岩浆对于斑岩型铜钼矿成矿具有重要作用,提供了成矿的物质和流体,暗色微粒包体对于斑岩型铜钼矿地质找矿具有指示意义。Machangqing intrusive is a typical intrusive body of the alkali-rich intrusive rock belt in western Yunnan, and in which a large number of mafic microgranular enclaves have been found. While petrological, petrochemical and St, Nd, Pb isotopic data of mafic microgranular enclaves and their host rocks show that the Machangqing intrusive was generated from magma mixing, and formed in the tectonic background of Cenozoic continental crust thickening. These data also show that the mafic microgranular enclaves were derived from the enriched mantle magmas while their host granite porphyry were derived from felsic magmas of the continental crust. And both the mific microgranular enclaves and their host rocks were created as a result of the magma emplacement and magma mixture that evoked by the underplating of mantle derived magma and then the melting of the continental crust that above it. Mantle-derived magmas play an important role in the porphyry copper--molybdenum deposit as they furnished ore-forming materials and fluids to them, and also the microgranular enclaves could be an important index in porphyry copper--molybdenum deposit prospecting.

关 键 词：暗色微粒包体 寄主岩 岩石化学 SR Nd PB同位素 形成机制 马厂箐岩体 

分 类 号：P588.12[天文地球—岩石学]