Complex Lithospheric Deformation in Eastern and Northeastern Tibet From Shear Wave Splitting Observations and Its Geodynamic Implications

doi:10.1029/2018JB017081

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 岩石圈演化国家重点实验室

	Complex Lithospheric Deformation in Eastern and Northeastern Tibet From Shear Wave Splitting Observations and Its Geodynamic Implications
	Gao, Yifan 3,4; Chen, Ling 2,3,4; Wang, Xu 3,4; Ai, Yinshuang 1,2,3
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
	2019-10-16
页码	16
关键词	Shear-wave splitting Seismic anisotropy Eastern Tibet Northeastern Tibet Crust-mantle decoupling Middle-lower crustal flow detachment
ISSN号	2169-9313
DOI	10.1029/2018JB017081
英文摘要	The eastern and northeastern Tibetan Plateau is a key region to study the growth and expansion of the plateau and associated extrusion tectonics. We studied the seismic anisotropic structure in this region by shear wave splitting analysis of teleseismic records from a dense linear seismic array, to constrain the lithospheric deformation and processes. We detected small-scale variations in anisotropy, including changes of splitting parameters around major faults and different anisotropy patterns among individual tectonic blocks and units but with consistent interior features. Our results combined with previous observations suggest that, in addition to the dominant effects of lateral extrusion induced by the India-Eurasia collision, major faults and tectonic heterogeneity may have also exerted significant impacts on the deformation and thus anisotropic structure of the lithosphere. In particular, we constructed two-layer anisotropy models for both the Longmenshan subblock in the easternmost Songpan-Ganzi terrane and the western Qinling orogen, indicating crust-mantle decoupling in these areas. The lower anisotropic layer of both areas shows a general NW-SE fast polarization direction. We attribute this feature to the large-scale mantle deformation, due to the lateral extrusion of Tibet associated with the India-Eurasia collision. The upper-layer anisotropy in both areas features an optimal NEE-SWW fast polarization direction. While in the Longmenshan subblock it may stem from crustal deformation under the combined effects of middle-lower crustal flow, faulting, and tectonic heterogeneity, that in the western Qinling orogen is probably resulted from shearing caused by upper crustal displacement along a midcrustal detachment.
资助项目	Chinese Academy of Sciences[GJHZ1776] ; Chinese Academy of Sciences[XDA20070302] ; National Natural Science Foundation of China[41688103] ; [2011ZX05008001] ; [SinoProbe-02-03] ; [SKL-Z201704-11712180]
WOS关键词	LOWER CRUSTAL FLOW ; MANTLE BENEATH TIBET ; SEISMIC ANISOTROPY ; KUNLUN FAULT ; CHINA ; PLATEAU ; ROCKS ; COLLISION ; TOMOGRAPHY ; SUBDUCTION
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	AMER GEOPHYSICAL UNION
WOS记录号	WOS:000490402100001
资助机构	Chinese Academy of Sciences ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; Chinese Academy of Sciences ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/93917]
专题	地质与地球物理研究所_岩石圈演化国家重点实验室
通讯作者	Chen, Ling
作者单位	1.Chinese Acad Sci, Key Lab Earth & Planetary Phys, Inst Geol & Geophys, Beijing, Peoples R China 2.Chinese Acad Sci, Cen Ter Excellence Tibetan Plateau Earth Sci, Beijing, Peoples R China 3.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing, Peoples R China 4.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing, Peoples R China
推荐引用方式 GB/T 7714	Gao, Yifan,Chen, Ling,Wang, Xu,et al. Complex Lithospheric Deformation in Eastern and Northeastern Tibet From Shear Wave Splitting Observations and Its Geodynamic Implications[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2019:16.
APA	Gao, Yifan,Chen, Ling,Wang, Xu,&Ai, Yinshuang.(2019).Complex Lithospheric Deformation in Eastern and Northeastern Tibet From Shear Wave Splitting Observations and Its Geodynamic Implications.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,16.
MLA	Gao, Yifan,et al."Complex Lithospheric Deformation in Eastern and Northeastern Tibet From Shear Wave Splitting Observations and Its Geodynamic Implications".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH (2019):16.