【摘要】 高邮凹陷深凹带生长断层研究对深入了解该区的构造演化和油气成藏具有重要意义。本项研究在高精度三维地震资料解释基础上,结合生长断层的位移-长度关系和不同时期的断层落差,揭示了高邮凹陷深凹带东部的边界断层和次级断层的生长特征,并结合构造应力场数值模拟探讨了断层生长的主控因素。结果表明,深凹带真2边界断层在始新世戴南期由六个生长中心发育而成,始新世三垛期互相连接形成四个亚段。真2边界断层的生长过程表现为始新世戴南期各断层亚段长度快速增加和始新世三垛期断层位移的持续增大及各断层亚段的连接。真2边界断层生长过程中,断层走向和断面形态受到伸展边界断层真1断层的控制,断层各亚段连接处的结构受断层相互作用影响。深凹带内次级断层呈NEE走向段和近EW走向段交替出现的锯齿形,始新世戴南期生长时具有多个位于NEE走向段生长中心。次级断层的生长受控于古新世和始新世两期的应力场变化,体现为古新世NNW-SSE向伸展下形成NEE走向的薄弱面,在始新世近南北向伸展下NEE走向的薄弱面首先形成断层并被后期近东西向断层连接。更多还原

【Abstract】 Study of fault growth in deep area of the Gaoyou Sag has great significance for the understanding of the structural evolution and hydrocarbon accumulation of the Gaoyou Sag. Based on high-precision 3D seismic data,the displacement-length relationship and throw data of faults are integrated to reconstruct the growth of the boundary fault and secondary faults in the eastern deep area of the Gaoyou Sag and controlling factors of the fault growth are discussed by analyzing the tectonic stress field and numerical simulation. This study revealed that the Zhen 2 boundary fault had six segments which grew independently in the Eocene Dainan Period and subsequently linked into four segments in the Eocene Sanduo Period. The Zhen 2 fault growth included two phases: short rapid lateral lengthening initially in Dainan Period,followed by a longer phase of slip accumulation and linkage of segments in the Sanduo Period. The strike of Zhen 2 fault which is widely and gently undulate kept in step with Zhen1 extensional boundary fault that controlled the structural evolution of the Subei Basin. The structure of Zhen 2 fault tips is contributed to interaction of fault segments. Two segments overlapped and linked with its neighbor by relay zone,otherwise the segments kept away from the fault and linked near the tip of the fault which interacting the growth progress. The secondary faults are linked alternatively by segments of NEE strike and EW strike and the segments of NEE strike are developed initially in the Dainan Period. Numerical simulation demonstrated that the extensional direction in the area of secondary faults is parallel to the extensional direction of the region and barely influenced by the Zhen 2 boundary fault. The orientational change of the tectonic stress field between the Paleocene and Eocene led to the linkage of secondary faults,which means that the segments of NEE strike are developed by pre-existing fabrics of the Paleocene and the segments of EW strike linked the NEE segments later in the Eocene.更多还原