西藏的缝合带与特提斯演化  

Suture Zones in Tibetan and Tethys Evolution

作　　者：曾庆高 王保弟[2] 西洛郎杰 毛国正 刘海永 刘恭喜 Zeng Qinggao;WangBaodi;Xiluo Langjie;Mao Guozheng;Liu Haiyong;Liu Gongxi(Tibet Bureau o f Geological and Mineral Exploration and Development,Lhasa 850000,China;Chengdu Center of China Geological Survey,Chengdu 610081,China;West Exploration Group,Tibet Bureau of Geological and Mineral Exploration and Development,Lhasa 851400,China;Tibet Geological Survey y Lhasa 850000,China;Geothermal Geological Brigade,Tibet Bureau of Geological and Mineral Exploration and Development,Lhasa 851400,China)

机构地区：[1]西藏自治区地质矿产勘查开发局,西藏拉萨850000 [2]中国地质调查局成都中心,四川成都610081 [3]西藏自治区地质矿产勘查开发局西勘集团,西藏拉萨851400 [4]西藏自治区地质调查院,西藏拉萨850000 [5]西藏自治区地质矿产勘查开发局地热地质大队,西藏拉萨851400

出　　处：《地球科学》2020年第8期2735-2763,共29页Earth Science

基　　金：中国地质调查局项目(Nos.121201102000150012,DD20190053)。

摘　　要：西藏的缝合带一直是西藏高原基础地质研究中最热门的科学问题之一.立足于西藏高原4条主要缝合带的物质组成、缝合结构以及形成时代等资料,根据时空结构分析认为古特提斯演化与转换构造有关,雅鲁藏布江洋盆扩张与羌塘-三江地区的印支运动具有耦合的时空变换关系;重点讨论了以班公湖-怒江带为中心的古-新特提斯转换扩张性质,构造体制上属左行走滑拉分,形成了西藏高原上颇具特色的与走滑拉分方向平行的伸展构造类型杂岩系,其重要意义不亚于高原周缘逆冲-拆离系构成的杂岩系和美国西部的盆-岭变质核杂岩;探讨了西藏东、西部地区不同地质结构的科学问题,提出了冈底斯岩浆弧拓展加宽受雅鲁藏布洋双重俯冲的制约.The study of suture zones in Tibet is always one of the hottest scientific problems related to the fundamental geology of Tibetan Plateau.Based on the composition,tectonic and formation ages for the four suture zones in the Tibetan Plateau,and through the analysis of spatial-temporal structure,it is proposed that the evolution of the Paleo-Tethys was related to the transform faults.The expansion of the Yarlung Zangbo Ocean Basin shows space-time transformation coupled with the Indosinian orogeny in the Qiangtang-Sanjiang area.Focusing on the Paleo-Tethys and Neo-Tethys transformation and expansion properties of the Bangong-Nujiang belt,it is found in this study that its tectonic mechanism is left-lateral strike-slip and pull-apart,which have resulted in a series of extensional complexes parallel to the strike-slip and pull-apart,and so it is as important as that of the thrust back sliding detachment system on the basin-ridge metamorphic core complex in the western United States.In this paper,it also discusses the difference of geological structures in eastern and western Tibet,and proposes that the expansion and widening of the Gangdese magmatic arc were constrained by the double subduction of the Yarlung Zangbo Tethys Ocean.

关 键 词：缝合带 转换断层 走滑型边界 原特提斯 古特提斯 新特提斯 构造地质学 

分 类 号：P54[天文地球—构造地质学]