西昆仑北缘新元古代片麻状花岗岩锆石SHRIMP年龄及其意义  

Zircon SHRIMP Age of Neoproterozoic Gneissoid Granites in the West Kunlun and Its Significance

作　　者：张传林[1] 杨淳[2] 沈加林[3] 王爱国[3] 赵宇[3] 董永观[3] 郭坤一[3] 

机构地区：[1]中国科学院地球化学研究所,贵阳550002 [2]中国地质科学院地质研究所,北京100037 [3]南京地质矿产研究所,210016

出　　处：《地质论评》2003年第3期239-244,共6页Geological Review

基　　金：中国地质调查局"中国前寒武纪重大地质问题研究"课题(编号200113900070);"西昆仑前寒武纪构造事件群研究"专题部分成果

摘　　要：在西昆仑北缘早前寒武纪变质地层中,笔者等识别出大量不同时代的片麻状花岗岩,其中包括新元古代片麻状花岗岩。获得最新的新元古代片麻状花岗岩的单颗粒锆石SHRIMP年龄为815±57Ma,片麻状花岗岩的岩石学特征反映它们形成于裂解构造背景,结合对区域上新元古代地层及中元古代末期构造事件的研究,笔者认为新元古代片麻状花岗岩反映了古塔里木板块作为Rodinia超大陆一员发生裂解的时间,这对研究古塔里木板块在Rodinia超大陆中的位置及中国Rodinia超大陆裂解的研究提供了重要的地质依据。A lot of gneissoid granites were recognized in the early Precambrian metamorphic rocks in the northern West Kunlun, including Neoproterozoic granites. Zircon SHRIMP dating of the Neoproterozoic granites yields an age of 815±57 Ma, and their geochemistry shows that they were formed in a rifting environment. Along with the Neoproterozoic strata and metamorphism at the end of the Mesoproterozoic, the Neoproterozoic gneissoid granites recorded the time of the breakup of the Paleo -Tarim plate, which was a part of Rodinia. This study supplies new and important geological data to locate the Paleo-Tarim plate in Rodinia.

关 键 词：片麻状花岗岩 新元古代 裂解构造 古塔里木板块 RODINIA超大陆 成岩时代 锆石 SHRIMP年龄 

分 类 号：P597[天文地球—地球化学]