Seismic anisotropy beneath the southern Ordos block and the Qinling-Dabie orogen, China: Eastward Tibetan asthenospheric flow around the southern Ordos

Yu, Yong1; Chen, Yongshun John1,2

2016-12

10.1016/j.epsl.2016.08.026

EARTH AND PLANETARY SCIENCE LETTERS   影响因子和分区

0012-821X

1385-013X

SKS wave splitting analysis is performed to estimate the seismic anisotropy in the upper mantle using teleseismic data recorded by a temporary seismic array of 180 stations called SOSArray deployed in the southern Ordos block and the Qinling-Dabie orogen. The most important finding is that large delay times with NW-SE fast polarization directions in the northeastern Tibet are continuous across the boundary into the southwestern part of the Ordos block, where the SKS wave splitting results are significantly different from those in the rest of the Ordos block. Based on our SKS wave splitting results in addition to the results from previous studies, we propose an asthenospheric flow model for the eastward extrusion of the Tibetan upper mantle. The model consists of two corner flows around the southwestern corner and the southeastern corner of the Ordos block and the eastward flow along the Weihe graben and the Qinling-Dabie orogen for the escaping Tibetan upper mantle. Finally, the clockwise turning flow of the asthenosphere around the southwestern corner of Ordos block has currently extended laterally into the interior of the Ordos block, suggesting that the thick cold lithospheric root of the southwestern Ordos block there is currently being replaced with hot Tibetan asthenosphere at depths, that is, we observed an on-going process of thermal erosion of a cratonic lithosphere by lateral hot asthenospheric flow. (C) 2016 Elsevier B.V. All rights reserved.

SKS wave splitting upper mantle anisotropy asthenospheric flow eastward extrusion of Tibetan mantle

SCI ; EI

英语

NI期刊

通讯

NSFC[91128210] ; NSFC[90814002]

Geochemistry & Geophysics

Geochemistry & Geophysics

WOS:000386738200001

ELSEVIER SCIENCE BV

20164302926699

Anisotropy ; Extrusion ; Seismology

Geology:481.1 ; Earthquake Measurements and Analysis:484.1 ; Physical Properties of Gases, Liquids and Solids:931.2

GEOSCIENCES

Web of Science

1.Peking Univ, Inst Theoret & Appl Geophys, Sch Earth & Space Sci, Beijing 100871, Peoples R China
2.South Univ Sci & Technol China, Sch Oceanog, Shenzhen 518055, Peoples R China

Yu, Yong,Chen, Yongshun John. Seismic anisotropy beneath the southern Ordos block and the Qinling-Dabie orogen, China: Eastward Tibetan asthenospheric flow around the southern Ordos[J]. EARTH AND PLANETARY SCIENCE LETTERS,2016,455:1-6.

Yu, Yong,&Chen, Yongshun John.(2016).Seismic anisotropy beneath the southern Ordos block and the Qinling-Dabie orogen, China: Eastward Tibetan asthenospheric flow around the southern Ordos.EARTH AND PLANETARY SCIENCE LETTERS,455,1-6.

Yu, Yong,et al."Seismic anisotropy beneath the southern Ordos block and the Qinling-Dabie orogen, China: Eastward Tibetan asthenospheric flow around the southern Ordos".EARTH AND PLANETARY SCIENCE LETTERS 455(2016):1-6.