The sequence of environment evolution of the Late Permian strata in this area is: the confining carbonate platform-the lagoons and the tidal flats-the shallow water deltas of sea.

• 海陆过渡环境演化顺序为:碳酸盐台地-泻湖潮坪-浅水三角洲聚煤成煤模式,和局限海底火山地台-泻湖潮坪-浅水三角洲聚煤成煤模式。