苏北-南黄海南部叠合盆地构造演化与海相油气勘探潜力

从板块作用机制入手,基于构造应力场、构造形迹和沉积建造等综合分析,把晚三叠世华南板块和华北板块碰撞以来苏北-南黄海南部叠合盆地的构造演化划分为4个阶段:1)晚三叠世-中侏罗世古特提斯洋关闭机制下的前陆盆地发育阶段;2)晚侏罗世-早白垩世伊佐奈歧板块斜向俯冲机制下的逆冲推覆构造体系发育阶段;3)晚白垩世-古近纪太平洋板块俯冲机制下的伸展盆地发育阶段,包括晚白垩世坳陷盆地发育阶段和古近纪断陷盆地发育阶段;4)新近纪喜马拉雅造山作用机制下的坳陷盆地发育阶段。关于古近纪箕状断陷(群)的发育过程,强调了NWW向基底断裂左行走滑拉分和NE向逆冲推覆体系分别对盆地形成和箕状断陷发育的控制作用,从建造-改造-保存的角度指出了海相油气系统赋存的有利地区。

Tectonic evolution of Subei-South Nanhuanghai superimposed basin from the Late Mesozoic to the Cenozoic and marine petroleum potential

Based on comprehensive study on tectonic stress field,structural feature,and sedimentary formation,the tectonic evolution of Subei-South Nanhuanghai(North Jiangsu-Southern South Yellow Sea) superimposed basin since the late Triassic plate collision between the Huanan plate and Huabei plate can be divided into the following four stages: ① the foreland basin development stage under the influence of the late Triassic to Middle Jurassic paleo-Tethyan closing;② the thrust nappe development stage controlled by the Late Jurassic-Early Cretaceous oblique subduction of Izanagi oceanic plate;③ the basin extension development stage under the in-fluence of the late Cretaceous-Paleogene subduction of the Pacific plate,including the late Cretaceous depression development stage and Paleogene fault depression basin development stage;④ the depression development stage under the influence of Neogene Himalaya orogenesis.In relation to the development of the Paleogene half-graben-like fault depression,this paper focuses on the controlling effects of the left-lateral strike-slip and pul-lingapart movement along with the NWW basement faults and of the NE thrust nappe over the development of the basin and half graben-like fault depression,and points out the exploration prospect of marine petroleum system from the aspect of sedimentation,reworking,and preservation.