Abstract:Geophysical data show that there are thrusts deep under the salt-rock layer of the Cambrian Gaotai Formation near Qiyue Mountain in the eastern margin of Sichuan Basin, the formation process of the thrusts and the geological significance of oil and gas have not been deeply studied.Methods: Based on the swath 3D and two-dimensional seismic reflection data in Shizhu and Jiannan area of eastern Sichuan Basin, combined with drilling datas and regional geological research results. Results: ① The tectonic deformation of the northern Qiyue Mountains in eastern Sichuan is strong, and the basement involved structure is widely developed. The structural style is controlled by the tectonic location of the Qingbaikou-Nanhua rift and transition belt. ② According to the structural inheritance relationship, Dengying Formation platform boundary belt can be divided into Deyang-Anyue primary type platform boundary belt, Wanyuan-Dazhou inherited type platform boundary belt and Shizhu inheritance-modified type platform boundary belt. ③ Based on the distribution of Qingbaikou-Nanhua rift and the influence of late tectonics, it is believed that there are inheritance-modified platform margin belts of Dengying Formation similar to Shizhu area along Qiyue Mountain southward to Nanchuan, and there are inheritance-modified platform margin belts of Dengying Formation in Zhongxian and the west of Nanchuan. ④ A complete reservoir-cap association is formed by Neoproterozoic Lower Cambrian source rock, Dengying Formation and Longwangmiao Formation beach facies dolomite reservoir and Cambrian salt-rock layer in the study area. ⑤ The pre-salt basement thrusts of Cambrian can form rows and belts, and the fault-related tectonic-lithologic trap with Dengying Formation's succinction-reformed platform margin belt and Longwangmiao Formation's shoal facies dolomite reservoir configuration has become a favorable area for oil and gas accumulation in east Sichuan.Conclusions: The Sinian-Early Cambrian in Shizhu area of eastern Sichuan Basin inherited the characteristics of Qingbaikou-Nanhua rift, while the Yanshanian tectonic inversion. The formation of the basement involved thrust structure under salt in the Gaotai Formation, which has the basic petroleum geological conditions such as reservoir cap, and has important practical significance for oil and gas exploration.