Genetic types of basal conglomerate of the Changzhougou Formation in the central sector of the Yanshan Mountains

According to the gravel composition, textures, distribution,occurrence and sedimentary facies sequence, basal conglomerate of the Changzhougou Formation in the central sector of the Yanshan Mountains may be classified according to its geneses into the alluvial fan sedimentary type, fluvial sedimentary type, fan delta type, and beach sedimentary type. The paper also discusses the facies paleogeographic framework of the early Changzhougou’an Yanshan basin.