The relationship between extension of lower crust and displacement of the shelf break

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

	The relationship between extension of lower crust and displacement of the shelf break
	Zhang, YF ; Sun, Z ; Pang, X
刊名	SCIENCE CHINA-EARTH SCIENCES
	2014
卷号	57 期号:3 页码:550-557
关键词	Baiyun Sag shelf break stretching factor lower crustal extension
ISSN号	1674-7313
通讯作者	zhensun@scsio.ac.cn
中文摘要	With deep sea petroleum explorations become more and more popular, some geological phenomena have emerged: extension of lower crust and upper crust is inhomogeneous; shelf break has been moved rapidly after crustal stretching. These geological phenomena are important to the continental margin evolution. To investigate the thinning of the whole crust and the contribution of the upper crust versus the lower crust to the crustal stretching since the Cenozoic, we calculated the stretching factors of the upper and the lower crust based on the 13 seismic lines in the Baiyun Sag from CNOOC. The results indicated that the whole crustal thickness decreases seaward while the whole crustal stretching factor increases from shelf to slope. Our calculations showed that the lower crustal stretching factor is higher than that of the upper crust in the Baiyun Sag. In the Cenozoic, deformation of the Baiyun Sag is controlled mainly by ductile shearing rather than brittle shearing. Based on the numerical modeling, we can conclude the initial crust in the Baiyun Sag is thermally attenuated. The stretching factor (beta) of the lower crust increases from the north to the south of the continental margin, indicating two stretching centers: the Baiyun Sag and the Liwan Sag. The geometry of the shelf break and the beta isoline trap have the similar trend in 23.8 and 13.8 Ma, both located in the intense deforming zone of the lower crust, and therefore we conclude the stretching and flowing of the lower crust cause the displacement of the shelf break before and after 23.8 Ma.
学科主题	Geology
收录类别	SCI
资助信息	National Science and Technology Major Project [2011ZX05025-003-005]; National Key Basic Research Development Plan [2009CB219401]; National Natural Science Foundation of China [41206040]
原文出处	SCIENCE PRESS
WOS记录号	WOS:000332662000017
公开日期	2014-12-11
内容类型	期刊论文
源URL	[http://ir.scsio.ac.cn/handle/344004/10641]
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	Zhang, YF,Sun, Z,Pang, X. The relationship between extension of lower crust and displacement of the shelf break[J]. SCIENCE CHINA-EARTH SCIENCES,2014,57(3):550-557.
APA	Zhang, YF,Sun, Z,&Pang, X.(2014).The relationship between extension of lower crust and displacement of the shelf break.SCIENCE CHINA-EARTH SCIENCES,57(3),550-557.
MLA	Zhang, YF,et al."The relationship between extension of lower crust and displacement of the shelf break".SCIENCE CHINA-EARTH SCIENCES 57.3(2014):550-557.