华南花岗岩暗色微粒包体的岩石化学组成特征及其意义  

Petrochemical composition characteristics of mafic microgranular enclaves in granites in SE China and their significance

作　　者：彭卓伦[1] Rodney Grapese 庄文明 张献河 

机构地区：[1]中山大学地球科学系,广东广州510275 [2]Department of Earth and Environmental Sciences,Korea University,Seoul 136 731,Korea [3]广东省佛山地质局,广东佛山528000 [4]广东省地质调查院,广东广州510080

出　　处：《地学前缘》2011年第1期74-81,共8页Earth Science Frontiers

基　　金：高等学校博士学科点基金项目(20070558033,20030558005);中央高校基本科研业务费专项资金项目(32110-3161318);中国地质调查局资助项目(200013000126)

摘　　要：对华南诸多花岗岩体暗色微粒包体的野外调查表明,非均一包体是包体中最普遍的类型,常具有暗色基性边。岩石化学分析结果表明,包体边缘的岩性为二长岩-石英二长岩-二长闪长岩,中心则为石英二长闪长岩-英云闪长岩。从包体中心到边缘,具有Si、Ca含量和Na/K比值降低,K、Al、Ti、P和Fe+Mg含量升高的变化趋势,揭示包体应来自岩石部分熔融的残余熔渣。进一步研究还表明,花岗岩中残余熔渣(暗色包体)的组分随着岩石熔融程度升高而向黑云母增多的方向演化,暗示富云包体应是岩石熔融演化至末阶段的产物。Inhomogeneous enclave is the most popular type in the mafic microgranular enclave（MME） of granites in SE China,which is generally with a dark or more mafic rim.The lithologic units in the rim of MME range from monzonite to quartz monzonite and to monzodiorite,while those in the core from quartz monzodiorite to tonalite.A MME generally has decreasing Si and Ca contents and Na/K ratios,and increasing K,Al,Ti,P and Fe＋Mg contents from its core to rim,indicating that the MMEs should have been mainly derived from restites of the partial melting rock.Further research revealed that the composition of restite in granites varies in the direction of increasing biotite as the melting degree of the rock increases and the biotite-rich enclaves should be the final product of rock melting process.

关 键 词：花岗岩 暗色微粒包体 岩石化学组成 部分熔融 

分 类 号：P588.121[天文地球—岩石学] P588.122[天文地球—地质学]