西藏拉萨地块南缘雄村矿集区首次发现早石炭世辉长岩:古特提斯洋的残留?  

The First Discovery of Early Carboniferous Gabbro in Xiongcun Area on the Southern Margin of Lhasa Terrane,Tibet: Remnants of Paleo-Tethys Ocean?

作　　者：郎兴海 唐菊兴[2] 邓煜霖 谢富伟 杨宗耀 崔志伟 王旭辉 李志军 张忠 张金树[4] 黄勇[5] LANG Xing-hai;TANG Ju-xing;DENG Yu-lin;XIE Fu-wei;YANG Zong-yao;CUI Zhi-wei;WANG Xu-hui;LI Zhi-jun;ZHANG Zhong;ZHANG Jin-shu;HUANG Yong(College of Earth Sciences and MLR Key Laboratory of Tectonic Controls on Mineralization and Hydrocarbon Accumulation,Chengdu University of Technology, Chengdu, Sichuan 610059;Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037;Tibet Tianyuan Minerals Exploration Co., Ltd., Shigatse, Tibet 857000;College of Engineering, Tibet University, Lhasa, Tibet 850012;Chengdu Center of China Geological Survey, Chengdu, Sichuan 610081)

机构地区：[1]成都理工大学地球科学学院,国土资源部构造成矿成藏重点实验室,四川成都610059 [2]中国地质科学院矿产资源研究所,北京100037 [3]西藏天圆矿业资源开发有限公司,西藏日喀则857000 [4]西藏大学工学院,西藏拉萨850012 [5]中国地质调查局成都地质调查中心,四川成都610081

出　　处：《地球学报》2017年第5期745-753,共9页Acta Geoscientica Sinica

基　　金：国家自然科学基金项目(编号:41172077;41502079);大陆构造与动力学国家重点实验室开放基金项目(编号:K201401);四川省教育厅自然科学重点项目(编号:15ZA0073);四川省青年基金项目(编号:2014JQ0047);中国地质调查局地质调查项目(编号:[资][2012]03-002-055;资[2014]01-028-042)联合资助~~

摘　　要：拉萨地块是研究特提斯洋形成演化和青藏高原陆内汇聚作用的关键地区,前人对拉萨地块中新生代构造演化过程进行了大量的研究,而对于古生代演化阶段研究较为薄弱。本文以拉萨地块南缘雄村矿集区新发现的辉长岩为研究对象,对雄村辉长岩进行锆石LA-ICP-MS U-Pb定年,探讨其反映的构造意义。雄村辉长岩中锆石LA-ICP-MS U-Pb年龄为(341.55±0.89)Ma,表明其形成于早石炭世。结合区域地质演化过程,认为早石炭世雄村辉长岩可能是古特提斯洋的残留,新的年龄数据将为研究拉萨地块和特提斯洋的演化过程提供重要的约束。Lhasa terrane is a key area in studying the formation and evolution of Paleo-Tethys and theintra-continental convergence in the Tibetan Plateau.Lots of precious studies have been devoted to the Cenozoicgeological evolution process in Lhasa terrane;nevertheless,the study of the Paleozoic evolution remains veryinsufficient.Focusing on the newly found Early Carboniferous gabbro in Xiongcun area on the southern margin ofLhasa terrane,the authors conducted zircon LA-ICP-MS U-Pb dating for gabbro in Xiongcun area,andinvestigated its tectonic significance.Zircon LA-ICP-MS U-Pb age of Xiongcun gabbro is(341.55±0.89)Ma,indicating that it was formed in Early Carboniferous epoch.Combining with the regional geological evolutionprocess,the authors consider that Early Carboniferous Xiongcun gabbro might be the remnant of Paleo-TethysOceanic crust,and the newly presented dating data would provide significant constraint for studying the evolutionprocess of Lhasa terrane and Paleo-Tethys Ocean.

关 键 词：拉萨地块 冈底斯带 辉长岩 古特提斯洋 雄村 西藏 

分 类 号：P588.124[天文地球—岩石学] P597[天文地球—地质学]