Permian system in Tazhong area may be divided into three lithology groups: lower clastic group, volcanics group and upper clastic group based on the data of core, drilling, logging and so on.

• 依据岩心、钻井、测井等资料,将塔中地区二叠系分为三个岩性组:下碎屑岩组、火山岩组、上碎屑岩组。