继承性构造与新生构造并存的时空发育特征及其油气勘探意义

中国及邻区大陆是经多期造山运动形成的复合大陆,后期构造可分为继承性构造和新生构造两种。两者在空间上的并存关系较为复杂,新生构造发育的强度可因地而异。东部新生代盆地(如苏北和渤海湾盆地),北东向构造属继承性构造,北北东向构造是新生构造,油气勘探的优选靶区是叠加在继承性构造之上的新生构造。中—东部的中生代盆地(如二连和鄱阳盆地)的油气勘探,除了寻找叠加在继承性构造之上的新生构造外,还应注意新生构造的发育引起的油气调整或晚期次生成藏。海相沉积盆地常上叠有陆相沉积盆地,因而发育多期多方向的新生构造并分别控制了岩性油藏和构造油藏的形成,如四川盆地东北部的两期(北西向和北东向)新生构造。以构造为主线,加强新生构造的解析并结合"源"、"运"和"聚"的研究,"盆"山"耦合理论将在生产实践中进一步显现其指导意义。

Time-spatial Developing Features of Co-existed Inherited and Neogenic Structures and Their Implications for Oil-gas Exploration

China and neighbouring continent is a composite one,resulted from amalgamation of microcontinents and blocks by multiple orogenies.According to the orientations,the younger structures can be classified into two basic kinds: inherited and neogenic structures.There is a complicated spatial relation of the both,and the intensity of neogenic structure's developing varies from place to place.For oil-gas exploration in the Cenozoic basins in East China,for example,the North Jiangsu and Bohai Bay basins where the NE structure was inherited one and the NEE structure was neogenic,the optimized targets might be neogenic structure superimposed the inherited ones.For the Mesozoic basins in middle-eastern China,such as the Erlian and Poyang basins,it should attend to,in addition to finding the neogenic structure superimposed the inherited ones,the oil-gas adjustment and later secondary reservation caused by occurring of the neogenic structure.The marine sedimentary basin was generally superimposed by continental basin,where multi-generation and multi-orientation neogenic structures developed and controlled the lithologic and structural oil-gas pools respectively.For example,there occurred two generations(NW-and NE-orientations respectively) of neogenic structures in the northeastern Sichuan Basin.To take structural study as the key link,to strengthen analyses on the neogenic structures,and to synthesize the works on source,migration and reservation,the theory of basin-orogeny coupling will guide concretely the oil-gas exploration practice.