Analysis on Permian Sedimentary Facies and Its Lithofacies Palaeogeographic Evolution,Northeast Sichuan Basin

By the research of outcrop profiles,logging profiles,logs and seismic data,seven types of sedimentary facies have been recognized on Permian Yanggudong profile in the Dukou town,Xuanhan County,NE Sichuan basin.The seven facies including strand swamp facies,platform evaporate facies,restraint platform facies,open platform facies,platform marginal reef facies,shelving facies and basinal facies.The study area developed three big transgressive-regressive cycles in the Permian period.On the basis of research of sedimentary evolution and palaeogeographic distribution,the sedimentary evolution model of carbonate facies is built in the northeast of the Sichuan basin.