气候变化领域集成服务门户(CCPortal): Quantifying Postrift Lower Crustal Flow in the Northern Margin of the South China Sea

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DOI	10.1029/2019JB018910
	Quantifying Postrift Lower Crustal Flow in the Northern Margin of the South China Sea
	Dong M.; Zhang J.; Brune S.; Wu S.; Fang G.; Yu L.
发表日期	2020
ISSN	21699313
卷号	125 期号:2
英文摘要	Postrift subsidence of sedimentary basins in the northern margin of the South China Sea exceeds more than 2,.000 m, which points toward anomalous postrift crustal deformation. Previous studies have proposed lower crustal flow to explain this observation; however, this hypothesis has never been confirmed quantitatively. Here, we calculate the initial crustal structure and thermal lithospheric thickness of the northern margin of the South China Sea on the basis of recently measured heat flow data, tectonic subsidence curves, and present-day crustal structure. Crustal thinning processes during rifting and reduced thickness of the lower crust in the postrift are also calculated by the strain rate inversion method and thermal isostasy. Our results show that the initial (Early Cenozoic) crustal thickness of the northern margin of the South China Sea varies between 27.7 and 36.3 km, and the average proportion of the lower crust is 67%. The initial thermal lithospheric thicknesses decrease from ~118 to ~81 km from the shelf to the sea, which indicates that the offshore margin has high temperatures and low strength and is more easily stretched and deformed. The average stretching factor the margin during rifting is 1.24. The lower crust reduces in thickness during the postrift phase by values between 1 and 11 km, which increases gradually from the shelf to deep water. We suggest that the thicker weak crust and hot lithospheric structure therefore make positive contribution to the lower crustal flow, the direction of which is from the oceanic basin to the shelf. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	anomalous postrift subsidence; lower crustal flow; rifted margins; South China Sea
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187939
作者单位	University of Chinese Academy of Sciences, Beijing, China; Laboratory of Marine Geophysics and Georesources, Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China; Geodynamic Modelling Section, GFZ German Research Centre for Geosciences, Potsdam, Germany; Institute of Geosciences, University of Potsdam, Potsdam, Germany; Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection, College of Resources and Environment, Linyi University, Linyi, China
推荐引用方式 GB/T 7714	Dong M.,Zhang J.,Brune S.,et al. Quantifying Postrift Lower Crustal Flow in the Northern Margin of the South China Sea[J],2020,125(2).
APA	Dong M.,Zhang J.,Brune S.,Wu S.,Fang G.,&Yu L..(2020).Quantifying Postrift Lower Crustal Flow in the Northern Margin of the South China Sea.Journal of Geophysical Research: Solid Earth,125(2).
MLA	Dong M.,et al."Quantifying Postrift Lower Crustal Flow in the Northern Margin of the South China Sea".Journal of Geophysical Research: Solid Earth 125.2(2020).