| Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau | |
| Li, GH (Li, Guohui)1,3; Bai, L (Bai, Ling)1; Zhou, YZ (Zhou, Yuanze)2,3; Wang, XR (Wang, Xiaoran)4; Cui, QH (Cui, Qinghui)2,3; Zhou, YZ | |
| Source Publication | TECTONOPHYSICS
 |
| 2017 | |
| Volume | 721Issue:0Pages:349-360 |
| DOI | 10.1016/j.tecto.2017.08.009 |
| Abstract | 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. |
| Subject Area | 地质学 |
| WOS ID | WOS:000418309400023 |
| Language | 英语 |
| Indexed By | SCI |
| Keyword | Emeishan Flood Basalts Hydrous Silicate Melt Earths Upper-mantle Deep Upper-mantle P-wave-form 410-km Discontinuity Seismic Discontinuities United-states Water Phase |
| WOS Research Area | Geochemistry & Geophysics |
| WOS Subject | Geochemistry & Geophysics ; Geochemistry & Geophysics |
| Cooperation Status | 国内 |
| Subtype | Article |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.itpcas.ac.cn/handle/131C11/7938 |
| Collection | 图书馆 |
| Corresponding Author | Zhou, YZ |
| Affiliation | 1.Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Continental Collis & Plateau Uplift, Beijing 100101, Peoples R China. 2.Chinese Acad Sci, Key Lab Computat Geodynam, Beijing 100049, Peoples R China. 3.Univ Chinese Acad Sci, Coll Earth Sci, Beijing 100049, Peoples R China. 4.Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China. |
| Recommended Citation GB/T 7714 | Li, GH ,Bai, L ,Zhou, YZ ,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 | Li, GH ,Bai, L ,Zhou, YZ ,Wang, XR ,Cui, QH ,&Zhou, YZ.(2017).Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau.TECTONOPHYSICS,721(0),349-360. |
| MLA | Li, GH ,et al."Velocity structure of the mantle transition zone beneath the southeastern margin of the Tibetan Plateau".TECTONOPHYSICS 721.0(2017):349-360. |
| Files in This Item: | ||||||
| File Name/Size | DocType | Version | Access | License | ||
| V.721 349-360 2017.p（2780KB） | 期刊论文 | 作者接受稿 | 开放获取 | CC BY-NC-SA | View Application Full Text | |
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