Crustal Structure and Extension from Slope to Deepsea Basin in the Northern South China Sea

CORC > 南海海洋研究所 > 中国科学院南海海洋研究所 > 中科院边缘海地质重点实验室

	Crustal Structure and Extension from Slope to Deepsea Basin in the Northern South China Sea
	Hu, DK ; Zhou, D ; Wu, XJ ; He, M ; Pang, X ; Wang, YW
刊名	JOURNAL OF EARTH SCIENCE
	2009
卷号	20 期号:1 页码:27-37
关键词	crustal structure Moho stretching Baiyun sag northern South China Sea
ISSN号	1674-487X
通讯作者	ben@scsio.ac.cn
中文摘要	The newly acquired long-cable multi-channel seismic (MCS) lines were used to study the crustal structure and extension in an NW-SE elongated 150 km by 260 km strip from the slope to the deepsea basin in the northern South China Sea (SCS). These profiles are of good penetration that Moho is recognizable in similar to 70% length of the lines. Seismostratigraphic interpretation and time-depth conversion were conducted. A power function D = alpha t(b) + c was used in the time-depth conversion, which avoided the under- or over-estimation of the depths of deep-seated interfaces by cubic or quadratic polynomial functions. Contour maps of basement depth, Moho depth, crustal thickness, and crustal stretching factor were obtained for the study area. In the dip direction, the Moho depth decreases stepwisely from 28 km in the outer shelf southwards to 19, 15, and 12 km in the deepsea basin, with ramps at the shelf break, lower slope, and the continent ocean boundary (COB), respectively. Accordingly, the crustal thickness decreased southwards from 25 to 15, 13, and 7 km, respectively. Under the center of the Baiyun (sic) sag, the crust thins significantly to < 7 km. The crustal stretching factor beta(c) was calculated by assuming the original crust thickness of 30 km. In the centers of the Baiyun sagg, beta(c) exceeds 5. Tertiary and Quaternary volcanic activities show a general trend of intensifying towards the COB. An important finding of this study is the along-strike variation of the crustal structure. A Moho rise extends from the COB NW-ward until the shelf break, about 170 km long and 50-100 km wide, with Moho depth < 20 km. This is called the Baiyun Moho Nose, which is bounded to the east, west, and north by belts of high Moho gradients indicative of crustal or even lithospheric faults. The doming of Moho in the nose area might be the cause of the W-E segmentation of the crustal and geological structures along the slope of the northern South China Sea, and the cause of the strong crustal stretching in the Baiyun and Liwan (sic) sags.
学科主题	Geosciences, Multidisciplinary
收录类别	SCI
原文出处	CHINA UNIV GEOSCIENCES
WOS记录号	WOS:000264753800003
公开日期	2011-07-03
内容类型	期刊论文
源URL	[http://ir.scsio.ac.cn/handle/344004/4636]
专题	南海海洋研究所_中科院边缘海地质重点实验室
推荐引用方式 GB/T 7714	Hu, DK,Zhou, D,Wu, XJ,et al. Crustal Structure and Extension from Slope to Deepsea Basin in the Northern South China Sea[J]. JOURNAL OF EARTH SCIENCE,2009,20(1):27-37.
APA	Hu, DK,Zhou, D,Wu, XJ,He, M,Pang, X,&Wang, YW.(2009).Crustal Structure and Extension from Slope to Deepsea Basin in the Northern South China Sea.JOURNAL OF EARTH SCIENCE,20(1),27-37.
MLA	Hu, DK,et al."Crustal Structure and Extension from Slope to Deepsea Basin in the Northern South China Sea".JOURNAL OF EARTH SCIENCE 20.1(2009):27-37.