华南花岗岩暗色微粒包体成因研究  

Genesis of mafic microgranular enclaves in granites in SE China

作　　者：彭卓伦[1] Rodney Grapes 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 [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82-88,共7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资助项目(32110-3161318);中国地质调查局资助项目(200013000126)

摘　　要：通过对暗色微粒包体的空间分布和形态特征以及包体矿物学、显微结构和岩石化学组成等方面的研究成果,在花岗岩"原地重熔"成因模型的基础上,建立了包体演化与熔渣演化的关系模型,证实包体的前身是捕虏体,后者代表从盖层落入岩浆中的岩块,包体则是岩块部分熔融后的残余物。不同类型、不同形态、不同基性度的包体,代表了岩石原地熔融过程中不同阶段的产物,富云包体反映了熔渣演化的最后阶段,在此基础上的进一步熔融即与寄主岩浆混成一体,完成了从岩石到岩浆的整个演化过程。Combing the field investigation of mafic microgranular enclaves（MMEs） in granites and the studies of geometry,mineralogy,microtexture and petrochemistry of enclaves,we advanced a model of evolution of MMEs and their relationship to the development of restites produced by partial melting of rock-blocks during the in-situ melting process.The model reveals that the xenoliths are the precursors of MMEs,and that the xenoliths are the rock-blocks coming into the magma from the cover of the magma layer during the melting and the MMEs are the mafic restites of the xenoliths.Variations in type,shape and maficity of MMEs reflect different melting degrees of rock-blocks.Biotite-rich enclaves are the final products of restite development,which will mix with the host granite magma in further melting,marking the end of the process from rock-block to granite magma.

关 键 词：花岗岩 原地重熔 暗色微粒包体 残余熔渣 

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