鄂西地区的大隆组富含菊石类化石 ,下部产 K onglingites、 Sanyangites、 Jinjiangoceras等 ,上部产 Pseu-dotirolites、 Tapashanites、 Changhsingoceras、 Pleuronodoceras等 ,时代为晚二叠世吴家坪晚期至长兴期。自西而东存在 3种沉积类型 ,即为硅质岩—灰、泥岩型、泥岩—硅质岩型和硅质灰岩—泥岩型。硅质岩层在区域上存在穿时性现象。大隆组与下伏吴家坪组的接触关系有两种 :连续沉积的整合接触和间断沉积的似整合接触 The Dalong Formation in western Hubei Province is rich in ammonite fossils, Kongglingites, Sanyangites and Jinjiangoceras in the lower part, and Pseu-dotirolites, Tapashanites, Changhsingoceras and Pleuronodoceras in the upper part of the sequence, dating from the Late Permian Wujiaping to Changxing Period. There are three sedimentary types from west to east, which are siliceous rocks-ash, mudstone type, mudstone-siliceous type and siliceous limestone-mudstone type. Siliceous strata exist in the region on time phenomenon. There are two types of contact between the Dalong Formation and the next Wujiaping Formation: the integrative contact between continuous deposition and discontinuous deposition