In No. 2 Coal Mine of Pingdingshan, the sedimentary environment of the lower stratum of Shanxi formation is considered as the tidal plat and the upperstratum and the result of delta systems.
平顶山二矿含煤地层山西组下部地层的沉积环境为潮坪，上部是三角洲体系的产物。
2
Southwestern Hubei area belongs to upper Yangtze subarea of Yangtze stratum area, the late Permian stratigraphic rock combination type is various.
鄂西南地区在地层区划上归属扬子地层区之上扬子分区，晚二叠世地层岩石组合类型多样。
3
Introducing into air drilling, nitrogen drilling and air percussion drilling were applied in Puguang upper continental facies stratum; moreover, drilled successfully into Xujiahe group stratum.