Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau

doi:10.1016/j.tecto.2017.08.009

	Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau
	Zhou, YZ ; Li, GH (Li, Guohui)2,3; Bai, L (Bai, Ling)3; Zhou, YZ (Zhou, Yuanze)1,2; Wang, XR (Wang, Xiaoran)4; Cui, QH (Cui, Qinghui)1,2
刊名	TECTONOPHYSICS
	2017
卷号	721 期号:0 页码:349-360
关键词	Emeishan Flood Basalts Hydrous Silicate Melt Earths Upper-mantle Deep Upper-mantle P-wave-form 410-km Discontinuity Seismic Discontinuities United-states Water Phase
DOI	10.1016/j.tecto.2017.08.009
文献子类	Article
英文摘要	P-wave triplications related to the 410 km discontinuity (the 410) were clearly observed from the vertical component seismograms of three intermediate-depth earthquakes that occurred in the Indo-Burma Subduction Zone (IBSZ) and were recorded by the Chinese Digital Seismic Network (CDSN). By matching the observed P-wave triplications with synthetics through a grid search, we obtained the best-fit models for four azimuthal profiles (I-IV from north to south) to constrain the P-wave velocity structure near the 410 beneath the southeastern margin of the Tibetan Plateau (TP). A ubiquitous low-velocity layer (LVL) resides atop the mantle transition zone (MTZ). The LVL is 25 to 40 km thick, with a P-wave velocity decrement ranging from approximately -53% to -3.6% related to the standard Earth model IASP91. An abrupt transition in the velocity decrement of the LVL was observed between profiles II and III. We postulate that the mantle structure beneath the southeastern margin of the TP is primarily controlled by the southeastern extrusion of the TP to the north combined with the eastward subduction of the Indian plate to the south, but not affected by the Emeishan mantle plume. We attribute the LVL to the partial melting induced by water and/or other volatiles released from the subducted Indian plate and the stagnant Pacific plate, but not from the upwelling or the remnants of the Emeishan mantle plume. A high-velocity anomaly ranging from approximately 1.0% to 1.5% was also detected at a depth of 542 to 600 km, providing additional evidence for the remnants of the subducted Pacific plate within the MTZ. (C) 2017 Elsevier B.V. All rights reserved.
学科主题	地质学
WOS研究方向	Geochemistry & Geophysics
语种	英语
WOS记录号	WOS:000418309400023
内容类型	期刊论文
源URL	[http://ir.itpcas.ac.cn/handle/131C11/7938]
专题	青藏高原研究所_图书馆
通讯作者	Zhou, YZ
作者单位	1.Chinese Acad Sci, Key Lab Computat Geodynam, Beijing 100049, Peoples R China. 2.Univ Chinese Acad Sci, Coll Earth Sci, Beijing 100049, Peoples R China. 3.Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Continental Collis & Plateau Uplift, Beijing 100101, Peoples R China. 4.Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China.
推荐引用方式 GB/T 7714	Zhou, YZ,Li, GH ,Bai, L ,et al. Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau[J]. TECTONOPHYSICS,2017,721(0):349-360.
APA	Zhou, YZ,Li, GH ,Bai, L ,Zhou, YZ ,Wang, XR ,&Cui, QH .(2017).Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau.TECTONOPHYSICS,721(0),349-360.
MLA	Zhou, YZ,et al."Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau".TECTONOPHYSICS 721.0(2017):349-360.