Abstract:

The purpose of this paper is to describe the characteristics of the differential deformation in superimposed basins and its control over the hydrocarbon accumulation. The differential deformation of superimposed basin is controlled by polyphase stress field transition, varied deformation medium, and various basin boundaries. The major characteristics of differential deformation are as follows. (1) Polyphase differential deformation controlled by the key tectonic movement and stress field transition. The horsegraben structures are formed under the regional extensional regime at the early stage; the detachment structures and buried hill－drape assemblages are generated relating to the convergent margins at the medium stage; the foldthrust belts are originated in the overlying foreland basins at the later stage. (2) Zonal differential deformation controlled by major fault belts is related to preexisting basement weak zones. The deformation intensity changed regularly in various structural zones. (3) Multilevel differential deformation controlled by decollement zones. The deeplevel detachment structures are associated with basinrange coupling; the mediumlevel detachment structures are related to basement decollement layers, and the shallowlevel detachment structures may have a bearing on plastic deformation associated with the salt bed or argillutite. (4) Segmental differential deformation controlled by transfer zones. The structural styles and kinematics may have a great difference in different segments because of the largescale transfer zones. The local transfer may form favorable oilgas traps. The differential deformation may be closely related to the development of  source rocks, the hydrocarbon accumulation epoch, the trap evolution, the distribution and preservation of  oilgas pools.

Key words: Key words: superimposed basin; differential structural deformation; detachment structure; transfer zone; hydrocarbon accumulation