| According to the relation to strata erosion, the paleotectonic framework of three uplifts and one sag developed before Middle Permian in Sichuan Basin. Based on field profile, core, thin-section, logging data, and seismic facies analysis, it is claimed that carbonate rimmed platform develope in Qixia Stage and Maokou Stage, in which some subfacies developed such as platform margin, open platform and platform basin, furtherly more microfacies can be identified including platform margin beach, inner-platform beach and siliceous platform basin. Controlled by paleotectonic framework, platform margin developed along the transition zone between the old uplift and slope-basin or between open platform and platform basin. Open platform developed in the old uplift and low uplift. Platform basin developed in the low sag. Comparing with the oil and gas exploration in Upper Permian Changxing Fm. and Lower Triassic Feixianguan Fm., it is suggested that the platform margin formed during Qixia Stage and Maokou Stage would be the next favorable exploration realms. |
