赣北星子群变质岩的原岩恢复及其形成构造环境判别  

Reconstruction of protoliths of metamorphic rocks of the Xingzi Group and discrimination of their tectonic setting

作　　者：张海祥[1] 张伯友[1] 

机构地区：[1]中国科学院广州地球化学研究所,广东广州510640

出　　处：《中国地质》2003年第3期254-260,共7页Geology in China

基　　金：中国科学院知识创新方向性项目(KZCX2-102)资助。

摘　　要：对星子群变质岩的原岩性质及其形成的构造环境研究表明,星子群变质岩中的片岩和变粒岩的原岩是沉积岩,其中云母片岩的原岩为粘土岩,石英片岩和变粒岩的原岩是杂砂岩或亚杂砂岩。斜长角闪岩、角闪片岩和榴闪岩的原岩为基性火山岩。变质沉积岩的形成构造环境判别结果表明,它们形成于活动大陆边缘环境。而变质基性火山岩属于岛弧拉斑玄武岩与大洋拉斑玄武岩的过渡类型,它们形成于拉张盆地。The study of nature of the protoliths of metamorphic rocks in the Xingzi Group and their tectonic setting shows that the protoliths of mica schist,quartz schist and granulitite(leptite)in metamorphic rocks of the Xingzi Group are sedimentary rocks.Among other things,the protolith of mica schist is claystone,those of quartz schist and granulitite are graywacke or subgraywacke and those of amphibolite,hornblende schist and garnet amphibolite are basic volcanic rocks.Discrimination of the tectonic setting of metasedimentary rocks indicates that the Xingzi Group formed on active continental margins.Metabasic volcanic rocks are a transitional type between island-arc tholeiite and mid-oceanic tholeiite.They were formed in extensional basins.

关 键 词：星子群变质岩 原岩恢复 构造环境 地球化学特征 

分 类 号：P588.3[天文地球—岩石学]