摘要
青海东昆仑南部寒武系沙松乌拉组碎屑岩中发现4006±11Ma碎屑锆石。这是迄今在青海省内获得的最古老年龄记录,也是我国境内发现的年龄大于4.0Ga的第4颗锆石。本次测试还获得了3.0Ga的碎屑锆石年龄以及一些~2.5Ga,~1.0Ga年龄峰值,~2.5Ga年龄是对原始中国古陆的五台运动的响应,并有可能成为基诺兰超大陆的组成部分,~1.0Ga年龄证明了Grenville期的地壳生长与再造,响应Rodinia超大陆汇聚事件。这些锆石年龄的发现引发了我们对该区早期地史演化是亲华北还是亲扬子的思考。4.0Ga碎屑锆石的发现表明沙松乌拉组物源区残留有少量冥古代的地壳物质,也为探讨青藏高原大陆生长提供了新的资料。
This paper reported the first discovery of 4006±11Ma detrital zircon in the metamorphic clastic rocks of Cambrian Shasongwula Group in Wenquan area,southern segment of East Kunlun.This is the oldest age record ever obtained in Qinghai Province and even in the northern part of the Qinghai-Tibet plateau.It is also the fourth zircon found in China older than 4.0Ga.The test also obtained a 3.0Ga detrital zircon and several other zircon grains with peak ages of^2.5Ga and^1.0Ga.It is considered that the^2.5Ga age is related to the first continental convergence in China and may be a part of the Nolan supercontinent.The^1.0Ga age is related to the crustal growth and reconstruction during the Grenville period and responds to the Rodinia supercontinent convergence event.The age of these zircons has proposed a problem,whether the early geological history of this region was pro-North China or pro-Yangtze Block.The discovery of 4.0Ga detrital zircon indicates that a small amount of crustal material from the Hadean Period remains in the source area of the Shasongwula Formation and this chronologic evidence provides new data for the study of continental growth in the Qinghai-Tibet Plateau.
作者
陈静
李彬
余福承
常涛
Chen Jing;Li Bin;Yu Fucheng;Chang Tao(School of Geographic Sciences,Qinghai Normal University,Xining,Qinghai 810000,China;The Third Geological Exploration Institute of Qinghai Non-ferrous Bureau,Xining,Qinghai 810000,China;School of Geology and Environment,Xi′an University of Science and Technology,Xi′an,Shanxi 710054,China;Qinghai Geological Survey Institute,Xining,Qinghai 810012,China)
出处
《矿物岩石》
CAS
CSCD
北大核心
2020年第3期20-25,共6页
Mineralogy and Petrology
基金
国家自然科学基金(41862011,41762006)
中国科学院“西部之光”人才培养引进计划。
关键词
沙松乌拉组
寒武系
碎屑锆石
东昆仑
Shasongwula Group
Cambrian
detrital zircon
East Kunlun
