Cenozoic Propagated Rifting in the Dangerous Grounds in Response to the Episodic Seafloor Spreading of the South China Sea  

作　　者：Yuanyuan Wang Yanghui Zhao Weiwei Ding Penggao Fang Jiabiao Li 

机构地区：[1]Collaborative Innovation Center of South China Sea Studies,Nanjing University,Nanjing 210093,China [2]Key Laboratory of Submarine Geosciences,Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China [3]Hubei Key Laboratory of Marine Geological Resources,China University of Geosciences,Wuhan 430074,China

出　　处：《Journal of Earth Science》2022年第4期1031-1046,共16页地球科学学刊（英文版）

基　　金：financially supported by the Open Fund of Hubei Key Laboratory of Marine Geological Resources(No.MGR202004);the National Natural Science Foundation of China(Nos.41890811,41676027,41906070)。

摘　　要：The southern continental margin of the South China Sea has documented multiphase continental rifting corresponding to the propagation of seafloor spreading.Here we investigate three multi-channel seismic reflection profiles across different segments of the Dangerous Grounds with a NE-SW direction.Stratigraphic correlation reveals that the Cenozoic tectono-stratigraphic framework in the Dangerous Grounds is featured with diachronous rifting,which records the successive spreading of East Subbasin and Southwest Subbasin,South China Sea.By reconstructing the tectono-sedimentary evolution history in different segments,we combine the quantification of the brittle extension,tectonic subsidence,as well as the crustal thinning.Results provide evidence that the extensional stress migrated from northeast to southwest with the progressive propagation of the seafloor spreading in the oceanic basin.Besides,the impact of the tectonic propagation persists even after the cessation of seafloor spreading,evidenced by a longer stretching duration in the West-Dangerous Grounds than that in the eastern area.Moreover,a temporary syn-rift subsidence delay synchronously to the spreading of the adjacent oceanic basin is observed along the southern margin.This observation proves the secondary mantle convection during the seafloor spreading in the southern continental margin,which is related to the propagating rift.

关 键 词：Dangerous Grounds South China Sea propagated rifting tectonic tectonic subsidence 

分 类 号：P736[天文地球—海洋地质]