早泥盆世古亚洲洋构造作用:来自可可托海和额济纳旗花岗岩年代学研究  

Paleo-Asian Ocean Tectonics in Early Devonian: Geochronology of Granites from the Koktokay and Ejina Banner

作　　者：密文天[1,2,3,4] 辛杰 彭逸飞 MI Wen-tian;XIN Jie;PENG Yi-fei(Key Laboratory of Geoscience Spatial Information Technology of Ministry of Land and Resources,Chengdu University of Technology,Chengdu 610059,China;Sichuan Key Laboratory of Natural Gas Geology,Southwest Petroleum University,Chengdu 610500,China;Geomathematics Key Laboratory of Sichuan Province,Chengdu University of Technology,Chengdu 610059,China;School of Mines,Inner Mongolia University of Technology,Hohhot 010051,China;Xinjiang Branch,Chinese Academy of Sciences,Urumqi 830011,China)

机构地区：[1]成都理工大学国土资源部地学空间信息技术重点实验室,成都610059 [2]西南石油大学天然气地质四川省重点实验室,成都610500 [3]成都理工大学数学地质四川省重点实验室,成都610059 [4]内蒙古工业大学矿业学院,呼和浩特010051 [5]中国科学院新疆分院,乌鲁木齐830011

出　　处：《科学技术与工程》2019年第32期58-68,共11页Science Technology and Engineering

基　　金：中国地质大学构造与油气资源教育部重点实验室开放课题(TPR-2017-13);中南大学有色金属成矿预测与地质环境监测教育部重点实验室开放基金(2017YSJS06);西南石油大学天然气地质四川省重点实验室开放基金(2016trqdz08);内蒙古工业大学教材建设项目(JC201712);国土资源部地学空间信息技术重点实验室开放基金(KLGSIT2016-02);数学地质四川省重点实验室开放基金(scsxdz201602);内蒙古自然科学基金(2018LH04006);内蒙古自治区研究生教育教学改革与实践项目(YJG20181012810)资助

摘　　要：古亚洲构造域内发育有大量的古生代酸性侵入岩。对阿尔泰造山带可可托海近3号脉的酸性侵入岩体进行LAICP-MS锆石U-Pb定年分析,以确定其岩浆作用时代及其岩浆活动的构造意义。研究区内的花岗岩包含的锆石大部分为自形-半自形晶,显示为典型的岩浆成因;测年结果发现,该岩体形成于(404.4±3.2)Ma,为早泥盆世岩浆活动的产物。通过对额济纳辉森乌拉西糜棱岩化二长花岗岩中白云母40Ar/39Ar同位素年代学分析,获得白云母的坪年龄和等时线年龄分别为(407.69±3.09)Ma和(407.65±3.99)Ma,这暗示了拐子湖-呼和音乌苏弧形挤压带在早泥盆世活动的冷却年龄。以上事件与早泥盆世古亚洲洋的俯冲、碰撞的构造环境关系密切。Study on the acidic igneous rocks in Koktokay and Ejina area,the ages of magmatism were determined for analyzing tectonic significance of magmatic activity in each periods.And the zircon U-Pb dating of the acidic intrusive rocks in Koktokay was conducted by LA-ICP-MS.The zircon from representative granite in Koktokay are the idiomorphic or hypidiomorphic,which showed magmatic genesis.The dating results indicated that the granite formed in the early Devonian.The geochronology of muscovite40 Ar/39 Ar in the mylonite granite from Ejina was conducted too.40 Ar/39 Ar plateau age and isochron age for muscovite is(407.69±3.09)Ma and(407.65±3.99)Ma respectively.These implies the cooling age of the Guaizi Lake-Huhe Yinwusu curved extrusion belt activities during the early Devonian.These ages indicated that the magmatic activity during the early Devonian related to the tectonic setting of the subduction and collision of Paleo-Asian Ocean.

关 键 词：古亚洲构造域 花岗岩 地质年代学 构造活动 

分 类 号：P581[天文地球—岩石学] P597[天文地球—地质学]