%0 Journal Article
%T GPS SURVEY AND THE RHEOLOGIC STRUCTURES WITH IN THE EASTERN TIBETAN PLATEAU<br>全球定位系统测量与青藏高原东部流变构造
%A Chen Zhiliang
%A Liu Yuping
%A Zhang Xuanyang
%A Zhao Jixiang
%A Tang Wenqing
%A Deng Changrong
%A B C Burchfiel
%A RW King
%A L H Royden
%A <br>陈智梁
%A 刘宇平
%A 张选阳
%A 赵济湘
%A 唐文清
%A 邓昌蓉
%A B. C. Burchfiel
%A R. W. King
%J 第四纪研究
%D 1998
%I 
%X The crustal inchon of the eastern Tibetan Plateau is the key to understand the collisionand post-collision intracontinental deformation betWeen South China and india, and toresearch the dynamic mechanism and process in Tibetan Plateau.As well-known, the eastern Tibetan Plateau is different from the central TibetMuch of the eastern margin of the Plateau lacks evidence for large-scale young crustalshortening and development of foreland basin, the folds and the thrust faults along theplateau margin are commonly oblique and older than the plateau margin. SinceMiocene,the tectonic frame in the eastern Tibet has been characterized by the wideright-lateral shear zone, which can be subdivided into three units: the weatern beltconsists mainly of a series of NW-trending en echelon right-lateral faults; the centralbelt-a series of NWW-trending en echelon left-latera faults, and the eastern belt-the western margin tectonic belt of the Yangtze block including the Longmenshan faults, the eastern Xianshuihe faults, the Xiaojiang faults, and the Honghe (Red River )faults .Since 1991, a regional GPS netWork has been established along the eastern Tibetan Plateau and its neighbor Sichuan Basin and Yunnan-Guizhou Plateau. The network hasbeen measured at least every two years using multi receivers of dual-frequency instatic relative positioning mode with carrier phase observation . The velocities of thosesites in the Chuan-Dian block and the west of Xianshuihe-Xiaojiang fault aresignificant high,most of them are 5- 10 mm / a relative to Chengdu, in contrast tothe weak movement in the Chuan-Qing and the Yangtze blocks east of the fault.Especially interesting is general clockwise vortex feature of velocity vectors in thesetwo areas. The vortex motion appears to be unrestricted by block boundaries andstrures ; on the contrary, it results in further segmentation within a block and alonga structure . Therefore it is the reflection of rheologic inchon of material in depthrather than those in the upper crust such as a brittle fault slip.Seismic profile research indicates that the thickening of crust in the eastern TibetanPlateau is mainly resulted from the development of lower-velocity layer within themiddle upper crust and the thickening of the lower crust and the contribution of eachof these two processes to the thickening of crust can be as large as 40%. But thedevelOPment of lower-velocity layer is probably an old orogenic process, as indicatedby the fact that most of duchle shear zone in the region is the Miocene or older inage. So, we suggest that the major Process responsible for the young surfacedeformation is a material flow in depth-probably lower crustal flow.The two vortexes structures resulting from the material flow in depth may betentatively named as the Dian -Zang vortex system and the western Sichuan vortexsystem.
%K GPS survey
%K eastern Tibetan
%K Plateau
%K rheologic structure<br>GPS
%K 青藏高原
%K 流变构造
%K 测量
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=621CF755B1A341E5&jid=EA07051745CDC8D89D5F01A3A4CFE6A9&aid=5377018C7508B316&yid=8CAA3A429E3EA654&vid=13553B2D12F347E8&iid=38B194292C032A66&sid=30897FA31CA3354D&eid=B7BFA4B351E4C682&journal_id=1001-7410&journal_name=第四纪研究&referenced_num=21&reference_num=13