【作者】 任建业； 庞雄； 雷超； 袁立忠； 杨林龙； 刘军；

【Author】 REN Jianye;PANG Xiong;LEI Chao;YUAN Lizhong;YANG Linlong;LIU Jun;Key Laboratory of Tectonics and Petroleum Resources of the Education Ministry,China University of Geosciences;China University of Geosciences;CNOOC Deepwater Development Co.Ltd.;

【机构】 中国地质大学构造与油气资源教育部重点实验室； 中国地质大学； 中海油深海开发有限公司；

【摘要】 本文阐明了OCT的现代概念和被动陆缘岩石圈伸展、薄化、剥露和裂解的新模式;描述了以OCT研究为基础而建立的南海北部被动陆缘地壳岩石圈结构构造单元划分方案及其基本特征,由陆向海将南海陆缘划分为近端带、细颈化带、远端带和外缘隆起带(含OCT)四个结构构造单元。研究提出深水-超深水盆地主要发育于细颈化带和远端带内,以地壳薄化和大型拆离断层及其所控制的拆离式盆地为特征。从琼东南盆地中央坳陷带,经白云-荔湾凹陷一直到台西南盆地,南海北部陆缘深水区发育有一个规模巨大的深水-超深水盆地群,构造演化史的研究表明,这些盆地的同裂陷阶段均经历了早期均一断陷和中晚期拆离式断陷演化过程,显示出南海北部陆缘岩石圈均一伸展、变形集中、迁移和最后破裂的规律。拆离断层及其所控制的拆离盆地是南海北部陆缘深水区盆地构型的新发现,为南海北部陆缘岩石圈的伸展演化过程分析提供了新的视角,同时也为科学评价深水-超深水盆地油气勘探潜力提供了新的思路。更多还原

【Abstract】 In this paper,we introduce the new concept of OCT and the lateset mechanisms associated with the lithospheric extension such as stretching,thining,mantle exhumantion and final breakup.The architectural elements of the passive margin in Northern South China Sea and their characteristics based on the research into the COT are detailed.The margin can be divided into four first-order domains,including the prioxmial,the necking,the distal,the outer high(contains OCT) domain.In the necking zone and the distal margin where deepwater basins are common,these basins are all charcterized by the extremly thinned crust underlying thick sediment and large-scaled detacment faults controlling thesurpa-detachment basins.There appear to be a deep water water basin group along strike,from the central depression zone in Qiongdongnan Basin to Baiyun-Liwan basin to Taixinan Basin.The integrated analysis of the tectionic evloution and the subsidence history on these basins show that all basins shared simliar rifting processes:the early streching phase followed by the late thinning phase,recording the regional distribution,localization and oceanward miargation of the rifting,which contribute to the fianl breakup of lithosphere.Therefore,our results provide a new perspective into the model of lithosperic extension under the northern margin of the South Chin Sea and have a great significance for economic exploration(hydrocarbon) in the deepwater and ultra-deepwater area of the South China Sea.更多还原