南海西南次海盆两侧陆缘中生代晚期构造接触关系  

Tectonic Contact Relationship of Continental Margins of the Southwest Sub-Basin, South China Sea in Late Mesozoic

作　　者：朱荣伟 姚永坚[1,2] 刘海龄[3] 徐子英 聂鑫[1,2] 杜文波[1,2] Zhu Rongwei;Yao Yongjian;Liu hailing;Xu Ziying;Nie Xin;Du Wenbo(Key Laboratory of Marine Mineral Resources,Ministry of Natural Resources,Guangzhou Marine Geological Survey,Guangzhou 510075,China;Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 511458,China;CAS Key Laboratory of Ocean and Marginal Sea Geology,South China Sea Institute of Oceanology,Chinese Academy of Science,Guangzhou 511458,China)

机构地区：[1]广州海洋地质调查局,自然资源部海底矿产资源重点实验室,广东广州510075 [2]南方海洋科学与工程广东省实验室(广州),广东广州511458 [3]中国科学院边缘海与大洋地质重点实验室,中国科学院南海海洋研究所,广东广州511458

出　　处：《地球科学》2021年第3期885-898,共14页Earth Science

基　　金：国家自然科学金项目(Nos.U20A20100,41776072);中国科学院边缘海与大洋地质重点实验室开放基金项目(No.OMG2019-05);中国地质调查局项目(Nos.DD20190627,DD20190366,DD20190378);南方海洋科学与工程广东省实验室(广州)人才团队引进重大专项(No.GML2019ZD0201)。

摘　　要：为探究南海西南次海盆两侧陆缘地块在中生代晚期构造接触关系及其对南海形成演化的影响,利用过南海西南次海盆两侧陆缘采集的地球物理资料以及公开发表的数据资料,对两侧陆缘的地壳结构及前新生界构造变形特征进行了研究.研究结果显示,西南次海盆两侧陆缘的地壳结构及物质组成存在差异,属于性质不同的两个微地块;两侧陆缘前新生代地层在晚中生代经历了来自不同方向的挤压作用,且遭受抬升剥蚀.结合南海及邻区中生代花岗岩分布特征及区域构造背景,进一步推测两侧陆缘地块在晚中生代以俯冲碰撞的方式完成拼贴缝合,该俯冲碰撞带是南海北部俯冲带在南海西南方向的延伸,并且新生代南海的扩张可能与该俯冲碰撞带这个先存的软弱带有关,是南海海盆初始破裂的部位.In order to study the tectonic contact relationship of continental margins of the southwest sub-basin, South China Sea in the Late Mesozoic, and its influence on the formation and evolution of the South China Sea, this paper analyzes the crustal structure and Pre-Cenozoic structural deformation of the continental margins of the southwest sub-basin of the South China Sea by the geophysical data and the published data collected from continental margins of the southwest sub-basin. The crust structure and material composition of the continental margins of the southwest sub-basin are different, belonging to two micro blocks with different properties. The Pre-Cenozoic strata of continental margins of the southwest sub-basin experienced compression from different directions in the Late Mesozoic, and suffered uplift and denudation. The continental margins of the southwestern subbasin were stitched together in the form of subduction collisions in the Late Mesozoic. The subduction zone is the extension of the northern South China Sea subduction zone to the southwest of the South China Sea. The expansion of the South China Sea in Cenozoic is related to the subduction zone, which is the initial fracture site of the South China Sea basin.

关 键 词：中生代晚期 构造接触关系 俯冲碰撞 西南次海盆 南海 海洋地质 

分 类 号：P736[天文地球—海洋地质]