扬子板块海相中古生界盆地的递进变形改造

印支—早燕山期由于古特提斯洋盆的关闭,扬子板块大陆边缘受到了挤压与碰撞作用,在板内形成了江南-雪峰基底拆离体(A带),从SE向NW方向的大规模水平推挤作用使扬子板内中古生界盆地发生了由强及弱的递进(衰减)变形改造。在其前缘形成了高角度冲断层-断弯褶皱带(B带)、逆掩断层-断展褶皱带(C带)、滑脱断层-滑脱褶皱带(D带)、共轭冲断层-膝折褶皱带(E带)和古隆起-单斜带(F带);在其后缘则形成了滑覆断层-滑脱褶皱带(G带)。不同的构造变形区带具有不同的水平位移量、压缩变形量,不同的逆冲断裂、褶皱的空间配置和不同的构造圈闭类型、保存条件,因而控制了不同类型的油气聚集与分布。

Progressive deformation of Middle Paleozoic marine basins in the Yangtze plate, China

Due to the closing of the Paleo-Tethys ocean basin during the Indosinian-early Yanshanian, the continental margin of the Yangtze plate was subjected to compression and collision, forming the Jiangnan-Xuefeng basement detachment (belt A) within the plate. Large-scale horizontal compression from SE to NW resulted in strong to weak progressive (decaying) deformation in Middle Paleozoic basins within the Yangtze plate. In its front there occurred a high-angle thrust-fault bend fold belt (belt B), an overthrust-fault propagation fold belt (belt C), detachment fault-detachment fold belt (belt D), conjugate thrust-kink fold belt (belt E) and paleo-uplift-monocline belt (belt F); whereas at its rear a sliding-overlapping-detachment fold belt formed (belt G). Different tectonic deformation areas have different amounts of horizontal displacement, different amounts of compressive deformation, different spatial dispositions of thrusts and folds and different types of structural traps and conservation conditions, thus controlling the accumulation and distribution of oil/gas of different types.