从地震看重力侧向滑动构造与油气——兼论马西逆同生断层不是反转构造

Seismic Profiles Show Lateral Gravitational Sliding Structures and Hydrocarbon Accumulation, and Account for the Maxi Contemporaneous Inverse Fault Instead of Reversion

重力构造作用分为侧向运动和垂向运动两大类。以渤海湾盆地及准噶尔盆地中的构造为实例,介绍了重力侧向滑动的六种构造样式,包括滑动断阶、逆牵引背斜、地层补偿堑背斜、滑落背斜、滑覆构造(逆同生断层)、推滑覆构造等。对其形成背景和形成机制逐一进行了分析,指明了这些构造的含油气潜力。这六种构造样式均可形成有利的油气圈闭,在勘探中应予以足够的重视。特别指出冀中坳陷马西逆同生断层不属于反转构造,而是由重力作用所产生的滑动推挤所致,为一典型的滑覆构造。

Gravity sliding can be divided into two sorts, the lateral and the vertical. Instanced by the sliding structures developed in Bohaiwan and Junggar basins, six types of lateral gravitational sliding structures are introduced, which includes a sliding fault step, an inverse drag anticline, a stratigraphic compensating graben-like anticline, a slide-fall anticline, a sliding overthrust structure （i.e. inversed contemporaneous fault）, and a sliding nappe. Their forming origin and mechanics are analyzed. All of these structures can be favorable hydrocarbon-bearing traps. It is suggested that a great attention should be paid to them in exploration. It is specially analyzed and indicated that the Maxi fault developed in Jizhong Depression is a typical sliding nappe, instead of a reversed fault, resulted from lateral compression of gravitational sliding movement.racrystalline pores and intracrystalline solution pores are common.