Pn tomography of South China Sea, Taiwan Island, Philippine archipelago, and adjacent regions

作者:Li, XB (Li, Xibing)^{[ 1,2 ]} ; Song, XD (Song, Xiaodong)^{[ 3,4 ]} ; Li, JT (Li, Jiangtao)^{[ 3 ]}

JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH

DOI: 10.1002/2016JB013787

出版年: FEB 2017

摘要

The South China Sea (SCS) and its surrounding areas are geologically highly heterogeneous from the interactions of multiple plates in Southeast Asia (Eurasian plate, Indian-Australian plate, Philippine Sea plate, and Pacific plate). To understand the tectonics at depth, here we combined bulletin and handpicked data to conduct Pn tomography of the region. The results show distinct features that are correlated with the complex geology at surface, suggesting a lithosphere-scale tectonics of the region. Low Pn velocities are found along a belt of the western Pacific transpressional system from the Okinawa Trough and eastern East China Sea, across central and eastern Taiwan orogeny, to the island arcs of the Luzon Strait and the entire Philippine Islands, as well as under the Palawan Island and part of the continental margin north of the Pearl River Basin. High velocities are found under Ryukyu subduction zone, part of the Philippine subduction zone, part of the Eurasian subduction beneath the southwestern Taiwan, and the continent-ocean boundary between the south China and the SCS basin. The Taiwan Strait, the Mainland SE coast, and the main SCS basin sea are relatively uniform with average Pn values. Crustal thicknesses show large variations in the study region but also coherency with tectonic elements. The Pn pattern in Taiwan shows linear trends of surface geology and suggests strongly lithosphere-scale deformation of the young Taiwan orogenic belt marked by the deformation boundary under the Western Foothill and the Western Coastal Plain at depth, and the crustal thickness shows a complex pattern from the transpressional collision. Our observations are consistent with rifting and extension in the northern margin of the SCS but are not consistent with mantle upwelling as a mechanism for the opening and the subsequent closing of the SCS. The Philippine island arc is affected by volcanisms from both the Asian and Philippine Sea subductions in the south but mainly from the Asian subduction in the north and under the Luzon Strait.

KeyWords Plus:UPPER-MANTLE BENEATH; VELOCITY STRUCTURE; CONTINENTAL-MARGIN; TECTONIC EVOLUTION; WAVE VELOCITY; EAST-ASIA; PLATE; COLLISION; KINEMATICS; ANISOTROPY

通讯作者地址: Song, XD (通讯作者)

通讯作者地址: Song, XD (通讯作者)

地址:

电子邮件地址:xiaod.d.song@gmail.com

基金资助机构授权号

AMER GEOPHYSICAL UNION, 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA

研究方向:Geochemistry & Geophysics

Web of Science 类别:Geochemistry & Geophysics

文献类型:Article

语种:English

入藏号: WOS:000396132200030

ISSN: 2169-9313

eISSN: 2169-9356