An overview of the crustal structure of the Tibetan plateau after 35 years of deep seismic soundings

作     者：Zhongjie Zhang~(a,*),Yangfan Deng~(b,c),Jiwen Teng~a,Chunyong Wang~d,Rui Gao~e,Yun Chen~a,Weiming Fan~b a State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China b Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China c Graduate University of Chinese Academy of Sciences,Beijing 100049,China d Institute of Geophysics,China Earthquake Administration,Beijing 100081,China e Institute of Geology,Chinese Academy of Geological Sciences,Ministry of Land and Resources,Beijing 100037,China 

会议名称：《中国科学院地质与地球物理研究所第11届（2011年度）学术年会》

会议日期：2012年

学科分类：070801[理学-固体地球物理学] 07[理学] 0708[理学-地球物理学] 

基　　金：The National Natural Science Foundation of China the Chinese Academy of Sciences the Ministry and the Land and Resources of China supported this overview through the Projects KZCX2-YW-132,40721003, 40830315 and Sinoprobe-02-02 

关 键 词：Wide-angle seismic profiling Crustal thickness Tibetan plateau 

摘      要：Since the pioneer wide-angle seismic profile along the Yadong-Gulu rift acquired in 1974 by the ex-Institute of Geophysics,Chinese Academy of Sciences(CAS),several research programs aimed to deep geophysics, performed thanks to the participation of Chinese national and international institutions,have been developed during last 35 years,including 23 wide-angle seismic profiles with total length of about 6000 *** profiles are unevenly distributed,most of them in eastern Tibet and few profiles in western *** this paper,we make a summarized presentation of all these wide-angle seismic profiles and provide an overall view of the seismic velocity structure of the crust beneath the broad Tibetan plateau, which is the product of the continuous convergence and collision of the Indian and Eurasian plates since about 50 Ma *** patterns of crustal thickness variation related to the tectonic blocks and along suture zones of the region are *** crust thickness is confirmed to be about 70-75 km under southern Tibet,and 60-65 km under northern,northeastern and southeastern *** leading edge of the subducted lithosphere reaches the northern margin of the plateau and directly contacts with Tarim *** of the 90°E boundary,the Indian crust is moving towards the northern edge of the plateau and collides with Tarim Basin at 80°E while reach the Bangong-Nujiang suture belt at 88°E;eastward of the 90°E boundary,the northern edge of the crust should be at 50-100 km south of Bangong-Nujiang *** results supply helpful constrains to understand the mechanism of the continent-continent collision and its consequences in the plateau and neighbouring areas.