气候变化领域集成服务门户(CCPortal): 3-D azimuthal anisotropy structure reveals different deformation modes of the crust and upper mantle in the southeastern Tibetan Plateau

CCPortal

DOI	10.3389/feart.2023.1095609
	3-D azimuthal anisotropy structure reveals different deformation modes of the crust and upper mantle in the southeastern Tibetan Plateau
	Zhang, Zhiqi; Feng, Jikun; Yao, Huajian
发表日期	2023
EISSN	2296-6463
卷号	11
英文摘要	The tectonic evolution and deformation process of the southeastern Tibetan Plateau has been one of the focuses of the geoscience community in recent decades. However, the crustal and mantle deformation mechanism in the southeastern Tibetan Plateau is still under debate. Seismic anisotropy inferred from surface wave tomography could provide critical insights into the deformation mechanism of the Earth's tectonosphere. Here, we constructed a 3-D azimuthal anisotropy velocity model with Rayleigh wave phase velocity dispersion data from 132 permanent stations to analyze the deformation modes in the southeastern Tibetan Plateau. In the upper crust, the azimuthal anisotropy near the main strike-slip faults exhibits strong magnitude with fast axis subparallel to the fault strike, which is consistent with the rigid block extrusion pattern. In the mid-lower crust, two low-velocity anomalies appeared beneath the Sonpan-Ganzi Terrane and Xiaojiang Fault zone with strong azimuthal anisotropy, which may indicate ductile deformation of the weak mid-lower crust. However, the two low-velocity anomalies are separated by a high-velocity barrier with weak azimuthal anisotropy in the inner zone of the Emeishan large igneous province. In the upper mantle, the anisotropy pattern is relatively simple in the rigid Yangtze Craton and mainly represents fossil anisotropy. In the southern part, the lithosphere thinned beneath the Indochina and Cathaysia Blocks, and the anisotropy is plausibly caused by the upwelling and lateral flows of upwelling hot asthenospheric materials.
关键词	southeastern Tibetan Plateau surface wave tomography azimuthal anisotropy asthenospheric upwelling deformation modes
英文关键词	EMEISHAN FLOOD BASALTS; LARGE IGNEOUS PROVINCE; SE TIBET; SEISMIC ANISOTROPY; LITHOSPHERIC STRUCTURE; SOUTHWEST CHINA; WAVE TOMOGRAPHY; EASTERN MARGIN; SW CHINA; BENEATH
WOS研究方向	Geosciences, Multidisciplinary
WOS记录号	WOS:000940127600001
来源期刊	FRONTIERS IN EARTH SCIENCE
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283883
作者单位	Chinese Academy of Sciences; University of Science & Technology of China, CAS; Chinese Academy of Sciences; University of Science & Technology of China, CAS; Chinese Academy of Sciences; University of Science & Technology of China, CAS
推荐引用方式 GB/T 7714	Zhang, Zhiqi,Feng, Jikun,Yao, Huajian. 3-D azimuthal anisotropy structure reveals different deformation modes of the crust and upper mantle in the southeastern Tibetan Plateau[J],2023,11.
APA	Zhang, Zhiqi,Feng, Jikun,&Yao, Huajian.(2023).3-D azimuthal anisotropy structure reveals different deformation modes of the crust and upper mantle in the southeastern Tibetan Plateau.FRONTIERS IN EARTH SCIENCE,11.
MLA	Zhang, Zhiqi,et al."3-D azimuthal anisotropy structure reveals different deformation modes of the crust and upper mantle in the southeastern Tibetan Plateau".FRONTIERS IN EARTH SCIENCE 11(2023).