Non-uniform hyper-extension in advance of seafloor spreading on the vietnam continental margin and the SW 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

	Non-uniform hyper-extension in advance of seafloor spreading on the vietnam continental margin and the SW South China Sea
	Li, L ; Clift, PD ; Stephenson, R ; Nguyen, HT
刊名	BASIN RESEARCH
	2014
卷号	26 期号:1 页码:106-134
ISSN号	0950-091X
通讯作者	pclift@lsu.edu
中文摘要	The SW South China Sea preserves a propagating oceanic spreading centre and associated continent- ocean transition (COT) that characterizes the continental margin offshore SE Vietnam. We investigated the nature of strain accommodation in the region immediately in front of the propagating rift using a combination of 1- and 2-D backstripping subsidence reconstructions, coupled with forward modelling based on the measured upper crustal extensional faulting applied to a flexural cantilever model. Major normal faulting ceases after an inversion event at ca. 16 Ma, although moderate extension was also noted at 22-23 Ma, representing the end of an extensional phase that initiated around 28 Ma. 1-D subsidence models indicate rapid 'syn-rift' subsidence, possibly lasting until 10 Ma, despite the lack of observed extensional faulting. We show that depth-dependent extension is required to explain the great depth of the basins despite the modest observed upper crustal faulting. Brittle faulting could not have extended much deeper than 10 km, suggestive of weak crust in the presence of high heatflow. The regional topographic slope on the basement suggests very low mid-crustal viscosities of 10(19)-10(20) Pa.s., consistent with the idea that flow in the ductile mid and lower crust was responsible for much of the subsidence prior to, and possibly after, seafloor spreading, which extended ca. 300 km from the tip of the mid ocean ridge. Flow is inferred to be dominant towards the spreading centre prior to 16 Ma. Extension in the COT postdates seafloor spreading and further supports the idea of this crust being very weak, albeit with more coherent, less extended crustal fragments, now forming banks offshore the Sunda continental shelf and surrounded by hyperextended crust of the COT.
学科主题	Geology
收录类别	SCI
原文出处	WILEY-BLACKWELL
公开日期	2014-12-11
内容类型	期刊论文
源URL	[http://ir.scsio.ac.cn/handle/344004/10649]
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	Li, L,Clift, PD,Stephenson, R,et al. Non-uniform hyper-extension in advance of seafloor spreading on the vietnam continental margin and the SW South China Sea[J]. BASIN RESEARCH,2014,26(1):106-134.
APA	Li, L,Clift, PD,Stephenson, R,&Nguyen, HT.(2014).Non-uniform hyper-extension in advance of seafloor spreading on the vietnam continental margin and the SW South China Sea.BASIN RESEARCH,26(1),106-134.
MLA	Li, L,et al."Non-uniform hyper-extension in advance of seafloor spreading on the vietnam continental margin and the SW South China Sea".BASIN RESEARCH 26.1(2014):106-134.