EVALUATION AND EVOLUTION OF THE MAJOR RIFT VALLEY OF MESO-CENOZOIC IN EASTERN CHINA

The main rift systems developed in Eastern China are Huaxia rift system, Fengwei rift system and Taidong rift system et al. Take Huaxia rift system as a typical example of continental rift evolution, which can be devided into four stages: dome and fracture stage, Spreading stage, rigional depression and depauperization stage, along with the evolution of rift valley there were mainly five types of structures: horst and graben fault (or basin and range structure); antithetic tilted fault block; symthetic tilted fault-block) step slip fault. Generally,the types of rift valleys are related to taphrogemic movement and orogeny, e.g. (1)impactogenic rift (Fengwei rift system) is related to arch trace) (2) convergent marginal rift (Taidong rift system) is related to oblique convergeny (3) continental fracturing rift (Huaxia rift system) is related to tensional shear fracture. Thus, the development of eastern rift system was controlled by the combination of taphrogeny,orageny, shearing, and gravitivity, while basal slip might be the dynamic force that caused the extension of rift valley. Rift valley basin is among the type of basin that has very promising prospect.