The depositional systems and coal accumulation in the Carboniferous Yangshan Formation at the northern foot of the Dabie Mountains

The Carboniferous Yangshan Formation is the sole coal-bearing strata in the northern Dabie Mountains.The present paper deals in detail with the development and evolution of the alluvial fan and fan delta depositional systems,potential areas of the swamp develop-ment,the relationship between the swamp formaton and the evolution of the depositional systems in the study area.The conclusion is that the commercial seams within the Yang-shan Formation generally lay down in the retrogradational fan deltaic plain facies.