东海盆地西湖凹陷斜坡区平湖断裂带分段性及其成因机制  

Segmentation and Genetic Mechanism of Pinghu Fault Zone in Xihu Sag Slope Area,East China Sea Basin

作　　者：唐贤君 钟荣全 陈永军 何新建 代勇 Tang Xianjun;Zhong Rongquan;Chen Yongjun;He Xinjian;Dai Yong(CNOOC China Limited,Shanghai Branch,Shanghai 200335,China)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335

出　　处：《吉林大学学报（地球科学版）》2024年第6期2047-2060,共14页Journal of Jilin University：Earth Science Edition

基　　金：中海石油(中国)有限公司重大科技专项项目(KJZX-2023-0101);中海石油(中国)有限公司综合科研项目(KJZH-2023-2103)。

摘　　要：为了揭示平湖断裂带的形成及演化过程,厘定大型断裂分段特征及其地层充填响应,深化对复杂断裂发育机制的认识,本文基于最新的三维地震资料,开展了平湖断裂带几何学、运动学分析,并结合区域应力场分析探讨了断裂成因及发育模式。研究结果表明:平湖断裂带是由NE走向与近NS走向交替出现的三个分段和五条主干断裂构成的“X”型断裂带;NE向断层段形成时间较早,具有分段发育特征,近NS向断层段形成时间较晚,控制了南、中、北段的分段链接;平湖断裂带复杂断裂的形成受始新世时期断裂分段生长发育和区域应力场旋转两种因素的共同控制;平湖断裂带断陷期生长演化过程划分为早期NE向断裂分段发育阶段、中期NE—近NS向断裂硬链接阶段和晚期近NS—NNE/NE向断裂张扭改造阶段。平湖断裂带发育演化的时空差异直接影响着该地区局部沉积、沉降中心迁移及裂后期挤压反转背斜的发育。In order to reveal the formation and evolution process of Pinghu fault zone,to determine the segmentation characteristics of large-scale faults and their geological filling response,and to deepen the understanding of the complex fault development mechanism,this article based on the latest 3D seismic data,conducts geometric and kinematic analysis of Pinghu fault zone.Combined with regional stress field analysis,the genesis and development mode of the faults are discussed.The research results indicate that:Pinghu fault zone is an“X”-shaped fault zone consisting of three segments and five main faults that alternate between NE and near NS.The NE fault segment formed earlier and has segmented development characteristics,while the NS fault segment formed later and controlled the segmented connections of the southern,central,and northern sections.The formation of complex faults in Pinghu fault zone is jointly controlled by two factors:The segmented growth and development of faults,and the rotation of regional stress fields during the Eocene.The growth and evolution process of Pinghu fault zone during the fault depression period is divided into three stages:Early NE fault segmentation development stage,middle NE-near NS fault hard connection stage,and late NS NNE/NE fault tension torsion transformation stage.The temporal and spatial differences in the development and evolution of Pinghu fault zone play an important controlling role in the migration of local sedimentary subsidence centers and the differential development of compression reversal anticlines in the later stages of the fault.

关 键 词：平湖断裂带 分段发育 成因机制 应力场旋转 西湖凹陷 东海盆地 

分 类 号：P548[天文地球—构造地质学] P618.13[天文地球—地质学]