气候变化领域集成服务门户(CCPortal): Formation of the North-South Seismic Zone and Emeishan Large Igneous Province in Central China: Insights from P-Wave Teleseismic Tomography

CCPortal

DOI	10.1785/0120200067
	Formation of the North-South Seismic Zone and Emeishan Large Igneous Province in Central China: Insights from P-Wave Teleseismic Tomography
	He, Chuansong; Santosh, M.
通讯作者	He, CS (通讯作者)
发表日期	2020
ISSN	0037-1106
EISSN	1943-3573
起始页码	3064
结束页码	3076
卷号	110 期号:6
英文摘要	The geodynamic features of the north-south seismic zone (NSSZ) and the formation of the Emeishan large igneous province (ELIP) in China remain controversial. In this study, we conducted detailed P-wave teleseismic tomography studies in the NSSZ and adjacent regions. The results revealed large high-velocity anomalies beneath the Songpan-Ganzi Block and the South China Block, possibly representing large-scale lithospheric delamination. We further identified low-velocity structures at 50-200 km depths in the western and southern parts of the NSSZ, suggesting an upwelling asthenosphere induced by delamination and the absence of a rigid lithosphere. Two high-velocity structures beneath the Sichuan basin and the Alashan block were also revealed, which may represent the lithospheric roots of these structures. These rigid lithospheric roots may have obstructed the eastward extrusion of the Tibetan plateau and led to stress accumulation and release (triggering earthquakes) in the Longmenshan Orogenic Belt and the northern part of the NSSZ. Because of this obstruction, the eastward extrusion was redirected southeastward to Yunnan in the southern part of the NSSZ, which led to stress accumulation and release causing earthquakes along the Honghe and Xiaojiang faults. The results from this study reveal a high-velocity structure with a subducted slab-like appearance that may represent vestiges of the Paleo-Tethys oceanic lithosphere, which subducted beneath the ELIP and initiating large-scale mantle return flow or mantle upwelling, contributing to the formation of the ELIP.
关键词	SOUTHEASTERN TIBETAN PLATEAU UPPERMOST MANTLE STRUCTURE RECEIVER FUNCTION-ANALYSIS BENEATH EASTERN CHINA SW CHINA LITHOSPHERIC STRUCTURE CRUSTAL STRUCTURE ACTIVE TECTONICS WESTERN SICHUAN AMBIENT NOISE
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000592938000028
来源期刊	BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/259921
推荐引用方式 GB/T 7714	He, Chuansong,Santosh, M.. Formation of the North-South Seismic Zone and Emeishan Large Igneous Province in Central China: Insights from P-Wave Teleseismic Tomography[J]. 中国科学院青藏高原研究所,2020,110(6).
APA	He, Chuansong,&Santosh, M..(2020).Formation of the North-South Seismic Zone and Emeishan Large Igneous Province in Central China: Insights from P-Wave Teleseismic Tomography.BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA,110(6).
MLA	He, Chuansong,et al."Formation of the North-South Seismic Zone and Emeishan Large Igneous Province in Central China: Insights from P-Wave Teleseismic Tomography".BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA 110.6(2020).