The Permian basin is divided into structural units each of which is characterized by a distinctive stratigraphic section. The Main Permian basin, Central basin platform, and Delaware Mountain basin are included in the transverse section presented in this paper. The strata of the Main Permian basin are divided into the Wichita-Albany, Clear Fork, and Double Mountain groups, the Double Mountain group being divided into the San Angelo, Blaine, Whitehorse-Cloudchief, and Quartermaster formations. The formations of the Main Permian basin are relatively uniform along the strike, but thicken and become more marine basinward.

The Central basin platform is a regional limestone "high" on which there are pronounced changes in the limestone section penetrated east and west across it. Two explanations of these changes are generally accepted. The first recognizes an extension of the Capitan reef system bordering the Delaware Mountain basin. Back of the reef is a lagoonal facies comprising dolomitic limestone, sandstone, and anhydrite. The second recognizes an older dolomitic limestone known as the "White lime," on the eroded surface of which there is a heterogenous deposit of dolomitic limestone, sandstone, and anhydrite known as the "Brown lime."

The strata of the Delaware Mountain basin comprise the Bone Springs limestone, the Delaware Mountain sandstone, the Capitan formation, the Lower Castile, Upper Castile, and Rustler formations. Of especial interest are the Capitan, which is a reef phase of the upper Delaware Mountain, and the Lower Castile, which is a peculiar evaporite formation.