Study On The Characteristics Of Major Fault Systems In Gaoyou Sag

The Mesozoic-Cenozoic basin in Subei has very complex structure backgrounds, especially its faults system, and Gaoyou sag is a typical representative. In order to explore the rules of major fault systems in Gaoyou sag, we begain from the character of main fault systems'geometry and kinematics, and think that Gaoyou sag is a stretched basin which is under the reason of NW-SE stretch, and in Zhenwu tectonic movement the direction of stretch is turn to NS. The fault Zhenâ‘ and Wuâ‘ are formed during the deposition of Taizhou formation, and most activity in the fourth member of Funing formation. The fault Zhenâ‘ and Wuâ‘ have inherit the structure features in Cenozoic. Zhenwu fault system is under the mechanism of extension, Wubao fault system's cause of formation is oblique slip. Therefore, Zhenwu fault system'evolution is gradually advancing to the internal depression, and the stretch of secondary faults roughly parallel to the boundary fault and its morphology controlled by boundary fault.Wubao fault system can divided into two belts, the area near the main fault is controlled by shear stress, for this reason, it can form many strike-slip faults, which is nearly east-west oriented. But the shear stress slight rapidly in areas far from the main fault, and form many extension faults, which mostly parallel to the main fault. Hanliu fault system appeared in the first member of Dainan formation, and ended in Sanduo tectonic movement. Meanwhile, we proposed the development patterns of Zhenâ‘¡,Hanliu fault system, Wubao fault system and Gaoyou main fault systems. We also think that the fault development has relationship with Curve-straight role, boundary fault and strike-slip effect.