Differential Deformation and Hydrocarbon Accumulation in the Superimposed Basins

Abstract This article describes the characteristics of the differential deformation in the superimposed basins and its control on hydrocarbon accumulation. The differential deformation of superimposed basin is controlled by polyphase stress field transition, varied deformation medium, and various basin boundaries. The main characteristics of differential deformation are as follows: (1) Polyphase differential deformation controlled by the key tectonic movements and stress field transition. The horse-graben structures are formed at the regional extensional regime at the early stage, the detachment structures and buried hill-drape assemblages are generated associated with the convergent margins at the medium stage, and the fold-thrust belts are originated in the overlying foreland basins at the later stage. (2) Zonal differential deformation controlled by major fault belts that are related to pre-existing basement weak zones. The deformation intensity is changed regularly in various structural zones. (3) Multi-level differential deformation controlled by decollement zones. The deep-level detachment structures are associated to basin-range decoupling, the medium-level detachment structures are related to basement decollement layers, and the shallow-level detachment structures might be having a bearing upon plastic deformation associated with the salt bed or argillites. (4) Segment differential deformation controlled by transfer zones. The structural styles and kinematics might have a great difference in different segments because of the large-scale transfer zones. The local transfer zones might form favorable oil-gas traps. The differential deformation might have a great bearing upon the development of the source rocks, the hydrocarbon accumulation epoch, the trap evolution, the distribution and preservation of the oil-gas pools.