Moho Structure of the Southwest Sub-Basin, South China Sea, from a Multichannel Seismic Reflection Profile NH973-1

作     者：ZHANG Jinchang CHEN Jie HUANG Yanming 

作者机构：CAS Key Laboratory of Ocean and Marginal Sea GeologySouth China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Fourth Institute of OceanographyMinistry of Natural ResourcesBeihai 536007China South China Sea Institute of Planning and Environmental ResearchMinistry of Natural ResourcesGuangzhou 510310China Key Laboratory of Exploration Technologies for Oil and Gas ResourcesMinistry of EducationYangtze UniversityWuhan 430100China 

出 版 物：《Journal of Ocean University of China》 (中国海洋大学学报（英文版）)

年 卷 期：2019年第18卷第5期

页      面：1105-1114页

核心收录：

学科分类：07[理学] 

基　　金：supported by the National Key R&D Program of China (No. 2018YFC03098 00) the National Natural Science Foundation of China (Nos. 91328205, 41376062, 91628301, U1606401, 4160 6 069, 41776058) the Natural Science Foundation of Guangdong Province in China (Nos. 2015A030310374, 2017A 030313243) the Chinese Academy of Sciences (Nos. Y4S L021001, QYZDY-SSW-DQC005) the China Association of Marine Affairs (No. CAMAZD201714) 

主　　题：Moho structure multichannel seismic reflection crustal structure South China Sea oceanic basin continent-ocean boundary 

摘      要：Moho structure provides important clues for understanding crustal structure,isostatic state and magmatic flux from mantle to ***-basin Moho structure of the South China Sea(SCS)is important for understanding crustal evolution mechanisms of both continental break-up and seafloor spreading *** Sub-basin(SWSB)opened up the latest and has the closest continental margins,making it the best to study the across-basin *** seismic(MCS)reflection data of line NH973-1 that crosses SWSB in NW-SE direction were reprocessed in order to image Moho *** MCS data,Moho reflectors are observed in places,which were not revealed in prior *** Moho generally shows symmetric structure on both sides of the central rift valley(CRV)and with variations in crustal *** CRV,the Moho is 2 seconds depth in two-way travel time(TWTT)beneath the igneous basement,which corresponds to 7 km depth,indicating normal oceanic crustal accretion during the ending of seafloor *** to the continent-ocean boundary(COB),the Moho becomes shallow to 1 second depth in TWTT(3.5 km),implying strong crustal thinning towards the continent,probably because of poor magma supply at the beginning of seafloor *** south COB,the Moho depth under the crust almost reaches zero,which could be explained as a result of exhumed *** addition,two low-angle,deep-penetrating normal faults are observed at south *** faults cut across the Moho into the upper mantle,which may be attributed to lithospheric hyper-stretching at COB during continental break-up.