气候变化领域集成服务门户(CCPortal): Crustal structure of the central Qaidam basin imaged by seismic wide-angle reflection/refraction profiling

CCPortal

DOI	10.1016/j.tecto.2012.09.005
	Crustal structure of the central Qaidam basin imaged by seismic wide-angle reflection/refraction profiling
	Zhao, Junmeng; Jin, Zhijun; Mooney, Walter D.; Okaya, Nihal; Wang, Shangxu; Gao, Xing; Tang, Liangjie; Pei, Shunping; Liu, Hongbing; Xu, Qiang
通讯作者	Zhao, JM (通讯作者)
发表日期	2013
ISSN	0040-1951
EISSN	1879-3266
起始页码	174
结束页码	190
卷号	584
英文摘要	We present the results of a seismic wide-angle reflection/refraction profile across the central Qaidam basin, the largest basin within the Qinghai-Tibetan plateau. The 350-km-long profile extends from the northern margin of the East-Kunlun Shan to the southern margin of the Qilian Shan. The P- and S-wave velocity structure and Poisson's ratio data provide constraints on composition. The crust here consists of a near-surface sedimentary layer and a four-layered crystalline crust having several significant features. (1) The sedimentary fill of the Qaidam basin reaches a maximum thickness of 8 km, and the basin shape mirrors the uplifted Moho. (2) Within the four layers of the crystalline crust, P- (S-) wave velocities increase with depth and fall within the following velocity ranges: 5.9-6.3 km/s (3.45-3.65 km/s), 6.45-6.55 km/s (3.7 km/s), 6.65 km/s (3.8 km/s), and 6.7-6.9 km/s (3.8-3.9 km/s), respectively; (3) low-velocity zones with a 3-5% reduction in seismic velocity are detected in the lower half of the crust beneath the Qaidam basin and its transition to the Qilian Shan. (4) The crystalline crust is thickest beneath the northern margin of the basin towards the Qilian Shan (58-62 km) and thinnest beneath the center of the basin (52 km). Variations in crustal thickness are caused most pronouncedly by thickness variations in the lowermost layer of the crust. (5) Poisson's ratio and P-wave velocity values suggest that the Qaidam crust has an essentially felsic composition with an intermediate layer at its base. Based on the crustal structure reported here, we suggest that late Cenozoic convergence is accommodated by thick-skinned tectonic deformation with thickening involving the entire crust across the Kunlun-Qaidam-Qilian system. (C) 2012 Elsevier B.V. All rights reserved.
关键词	ALTYN-TAGH FAULT TIBETAN PLATEAU VELOCITY STRUCTURE CONTINENTAL-CRUST POISSONS RATIO HEAT-FLOW CHINA MANTLE TECTONICS EVOLUTION
英文关键词	Qaidam basin; Tibet plateau; P- and S-wave velocity structure; Poisson's ratio; V-p/V-s ratio; Crustal composition
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000315613700017
来源期刊	TECTONOPHYSICS
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/258200
推荐引用方式 GB/T 7714	Zhao, Junmeng,Jin, Zhijun,Mooney, Walter D.,et al. Crustal structure of the central Qaidam basin imaged by seismic wide-angle reflection/refraction profiling[J]. 中国科学院青藏高原研究所,2013,584.
APA	Zhao, Junmeng.,Jin, Zhijun.,Mooney, Walter D..,Okaya, Nihal.,Wang, Shangxu.,...&Xu, Qiang.(2013).Crustal structure of the central Qaidam basin imaged by seismic wide-angle reflection/refraction profiling.TECTONOPHYSICS,584.
MLA	Zhao, Junmeng,et al."Crustal structure of the central Qaidam basin imaged by seismic wide-angle reflection/refraction profiling".TECTONOPHYSICS 584(2013).