Analysis on tectonic evolution and exploration potential in Dabashan foreland basin

On the basis of outcrop survey,seismic interpretation and a lot of coring data,the evolution and exploration potential of Dabashan foreland basin were analyzed. This foreland basin was formed in the mid-Yanshan cycle and underwent four stages including J 1—J 1 2 depression stage,J 2 2—J 3 foreland basin stage, K 1*.N basin shrunk and final deformation of thrust-folded end in Himalayan period. In this basin, two sets of high-quality resource rocks developed in the Daanzhai Formation and Lianggaoshan Formation have high abundance of organic matters which mainly contain Ⅱ 1 type and Ⅱ 2 type kerogen. The favorable assemblages of source-reservoir-cap rocks in Jurassic include self-generated and self-reservoir type Daanzhai Formation and Lianggaoshan Formation as well as lower-generated and upper-reservoir type lower Shaximiao Formation. The favorable plays include the thrust belt in Dabashan area,sag in the north Sichuan province and uplift in the central Sichuan province.