青海海西州乌北地体晋宁期柯柯沙花岗片麻岩锆石U-Pb年龄证据  

Zircon U-Pb age evidence of Jinning period Kekesha granite in North Wulan terrane,western Qinghai Province

作　　者：马建军 何川 王璐[1] 王珩 王勤燕 陈能松[1] MA Jianjun;HE Chuan;WANG Lu;WANG Heng;WANG Qinyan;CHEN Nengsong(School of Earth Sciences,China University of Geosciences,Wuhan 430074,Hubei,China;School of Earth Sciences,Zhejiang University,Hangzhou 310008,Zhejiang,China)

机构地区：[1]中国地质大学(武汉),地球科学学院,湖北武汉430074 [2]浙江大学地球科学学院,浙江杭州310008

出　　处：《地质通报》2019年第5期824-833,共10页Geological Bulletin of China

基　　金：国家自然科学基金项目《全吉地块北缘变质地体中—新元古代岩石成因和构造演化研究》(批准号:41372075)

摘　　要：在前人认为的震旦纪末期青海西部乌北地体柯柯沙花岗片麻岩中采集了2件同位素年龄样品,用LA-ICP-MS法测得其中锆石的206Pb/238U年龄加权平均值分别为826±6Ma(MSWD=0.84,n=12)和810±7Ma(MSWD=0.93,n=10)。这2个年龄值表明,柯柯沙花岗片麻岩属于晋宁运动早期的岩浆作用产物,与中国众多的晋宁期花岗岩一起响应了全球罗迪尼亚(Rodinia)超大陆在中国西北部的汇聚或离散演化。The Kekesha granite in North Wulan terrane of western Qinghai Province has been constrained to be formed at the end of Sinian period (543±13Ma) with thermal ionization mass spectrometer (TIMS) in the previous regional geological survey. In this study, the authors reported two U-Pb ages of 826±6Ma and 810±7Ma by in situ LA-ICP-MS dating method, which reveals that the intrusion of Kekesha granite was related to early Jinning Movement. The new result in conjunction with the other Jinning period granitoids documented information provides evidence for the assembly or breakup of the Rodinia supercontinent in Northwest China.

关 键 词：柯柯沙花岗岩 LA-ICP-MS锆石U-PB定年 乌北地体 罗迪尼亚超大陆 

分 类 号：P597.3[天文地球—地球化学] P588.345[天文地球—地质学]