渤海湾盆地南堡凹陷边界断层的“跃迁”特征及其成因机制  

Tectonic Model of Boundary Fault Migration and its Genetic Mechanism in the Nanpu Sag, Bohai Bay Basin

作　　者：童亨茂[1] 龚发雄[2] 孟令箭[2] 赵宝银 TONG Hengmao1, GONG Faxiong2, MENG Lingjian2 and ZHAO Baoyin2(1. State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, Beijing 102249, China; 2. Exploration and Development Research Institute, PetroChina Jidong Oilfield Company, Tangshan 063004, Hebei, Chin)

机构地区：[1]中国石油大学油气资源与探测国家重点实验室,北京102249 [2]中国石油冀东油田分公司勘探开发研究院,河北唐山063004

出　　处：《大地构造与成矿学》2018年第3期421-430,共10页Geotectonica et Metallogenia

基　　金：国家油气重大专项(2011zx05006-006-02-01);国家自然科学基金项目(41272160)联合资助

摘　　要：由于对裂陷盆地成盆和油气成藏要素的重要控制作用,边界断层在裂陷盆地构造研究中一直是被重点关注的研究对象。然而,关于边界断层在裂陷盆地演化过程中存在跃迁的认识还未见文献报道。本文在对南堡凹陷三维联片地震资料构造解析的基础上,应用"广义断层模式"(先存构造条件下的断层作用模式)及区域应力场演化成果,结合冀东油田最新的勘探成果,对南堡凹陷北部边界断裂进行了系统的构造解析,提出了边界断裂形成演化的新认识,建立了边界断层"跃迁"的构造模式。结果表明:(1)南堡凹陷在断陷阶段,随着应力场的演化,北边界断层是不断变迁的,存在显著的"跃迁"特征;(2)5号断层在E_2s^3期为凹陷西侧的北边界断层,高柳断层在E_3d^(1-2)期间为凹陷中部的北边界断层;(3)裂陷阶段应力场变化(伸展方向的改变)是导致裂陷盆地边界断层跃迁的根本原因。考虑到40～38 Ma伸展方向的改变涉及到几乎中国东南部所有的新生代裂陷盆地,预期边界"跃迁"的构造模式对中国东南部裂陷盆地的精细构造解析及油气勘探有普遍的启示意义。Due to the important control on basin formation and hydrocarbon accumulation, boundary faults have always been the focus of attention in the study of rift basins. However, researches on boundary fault migration in the rift basins have not been reported yet. On the basis of structural analysis of 3 D seismic data in the Nanpu Sag, faulting model of pre-existing weaknesses regional tectonic stress field results, and the latest exploration achievements in the Jidong Oilfield, the northern boundary faults in the Nanpu Sag were systematically analyzed. A new model of boundary fault（Boundary faults migration model） is proposed. The results show that：（1） in the rifting stage, with the evolution of tectonic stress field, the northern boundary faults are continuously migrating;（2） the No.5 fault is the northern boundary fault in E2s^3 era in the west side of the sag, and the Gaoliu fault is the northern boundary fault in E3d1-2 era in the middle of the sag;（3） the change of stress field（the extension direction） in the rifting stage is the primary cause for the boundary fault migration in the rift basin. Considering that the change of extension direction during 40–38 Ma involves almost all the Cenozoic rift basins in the eastern and southern China, the model of boundary fault migration is expected to have useful implication for fine structural interpretation and oil and gas exploration of the rifted basins in the east and south of China.

关 键 词：南堡凹陷 边界断层 先存构造 两期伸展 边界断层“跃迁” 

分 类 号：P542[天文地球—构造地质学]