Three-stage tectonic subsidence and its implications for the evolution of conjugate margins of the southwest subbasin, South China Sea

doi:10.1007/s00343-020-0259-3

IOCAS-IR > 海洋地质与环境重点实验室

	Three-stage tectonic subsidence and its implications for the evolution of conjugate margins of the southwest subbasin, South China Sea
	Wang, Wenlong 1,3,4; Dong, Dongdong1,2,4 ; Wang, Xiujuan 1,4; Zhang, Guangxu 1,4
	2021-04-24
发表期刊	JOURNAL OF OCEANOLOGY AND LIMNOLOGY
ISSN	2096-5508
页码	17
通讯作者	Dong, Dongdong(dongdongdong@qdio.ac.cn)
摘要	To reveal the tectonic characteristics of the continental margins in the southwest subbasin (SWB) of the South China Sea, a long high-resolution seismic profile was studied using empty basin subsidence. We find that tectonic subsidence features on both margins are uniformly divided into three stages: (1) slow subsidence from Tg to 18.5 Ma (synrift stage); (2) extremely slow subsidence/uplift from 18.5 to 16 Ma (spreading stage); and (3) accelerated subsidence from 16 to 0 Ma (post-spreading stage). This feature differs from the classic tectonic subsidence pattern of rifted basins, which exhibits fast subsidence during synrift stage and slow subsidence during the post-rift stage. The tectonic uplift occurred during the spreading stage and the magnitude increased from the continent to the ocean, which is likely related to mantle flow during seafloor spreading. We propose that lower crustal flow played a significant role in the tectonic evolution of the continental margins of the SWB. The lower crust of the SWB margins was warmer and therefore weaker, and more prone to flow beneath the faulting center, which compensated for the upper crustal thinning caused by brittle faulting during the synrift period and thus reduced the tectonic subsidence rate. During the spreading stage, faulting attenuated rapidly, and a necking zone appeared at the continent-ocean transition formed by lithospheric extension. With upwelling asthenosphere, small-scale secondary mantle convection occurred under the necking zone, which raised the continental margin isotherms and increased the buoyancy. Simultaneously, secondary mantle convection lifted the overriding crust, thus the overall subsidence rate decreased sharply or even reversed to uplift. After seafloor spreading, the effect of mantle convection faded away, and sediment loading drove the lower crust to flow landward. Thermal relaxation, lower crust flow, and vanish of secondary mantle convection together led to rapid subsidence in this stage.
关键词	tectonic subsidence lower crustal flow tectonic evolution southwest subbasin South China Sea
DOI	10.1007/s00343-020-0259-3
收录类别	SCI
语种	英语
资助项目	National Natural Science Foundation of China[41476042] ; National Natural Science Foundation of China[41776068] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDB42000000] ; Key Deployment Project of Centre for Ocean Mega-Research of Science, Chinese Academy of Sciences[COMS2019Q10] ; Key Deployment Project of Centre for Ocean Mega-Research of Science, Chinese Academy of Sciences[KEXUE2018G10]
WOS研究方向	Marine & Freshwater Biology ; Oceanography
WOS类目	Limnology ; Oceanography
WOS记录号	WOS:000643177000002
出版者	SCIENCE PRESS
引用统计	被引频次：4[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/170851
专题	海洋地质与环境重点实验室
通讯作者	Dong, Dongdong
作者单位	1.Chinese Acad Sci, Inst Oceanol, CAS Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China 2.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Geol, Qingdao 266061, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 4.Chinese Acad Sci, Ctr Ocean Megasci, Qingdao 266071, Peoples R China
第一作者单位	中国科学院海洋研究所; 中国科学院海洋大科学研究中心
通讯作者单位	中国科学院海洋研究所; 中国科学院海洋大科学研究中心
推荐引用方式 GB/T 7714	Wang, Wenlong,Dong, Dongdong,Wang, Xiujuan,et al. Three-stage tectonic subsidence and its implications for the evolution of conjugate margins of the southwest subbasin, South China Sea[J]. JOURNAL OF OCEANOLOGY AND LIMNOLOGY,2021:17.
APA	Wang, Wenlong,Dong, Dongdong,Wang, Xiujuan,&Zhang, Guangxu.(2021).Three-stage tectonic subsidence and its implications for the evolution of conjugate margins of the southwest subbasin, South China Sea.JOURNAL OF OCEANOLOGY AND LIMNOLOGY,17.
MLA	Wang, Wenlong,et al."Three-stage tectonic subsidence and its implications for the evolution of conjugate margins of the southwest subbasin, South China Sea".JOURNAL OF OCEANOLOGY AND LIMNOLOGY (2021):17.

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