In southeastern Arizona the Black Prince Limestone, Horquilla Limestone, Earp Formation, Colina Limestone, and Supai Formation are Pennsylvanian and Lower Permian strata with complex transgressive and regressive relations. Subdivision of these formations into easily recognizable lithologic members is possible only above the basal unconformities of the Black Prince and Horquilla Limestones where red clastic sediments intertongue with the predominantly limestone sequence. Lithologic facies changes in the upper part of the Horquilla Limestone pass laterally and vertically into the Earp Formation which intertongues upward with the overlying Colina Limestone and on the north with the lower part of the Supai Formation. Regional unconformities are common and 15 are recognized an traced as stratigraphic datum planes subdividing Pennsylvanian and Lower Permian strata into depositional units. These depositional units, dated by fusulinaceans, include Morrowan to early late Wolfcampian deposits. Only two regional hiatuses of long duration occur: one within the Derryan Series and the other at the base of the Missourian Series. Longer hiatuses occur locally where parts of the succession are missing because of lack of deposition or because of erosion associated with local structural adjustments.

Four main tectonic features influenced sedimentary environments in the region: the Papago inner shelf in the southwest received shallow marine sediments; the San Pedro outer shelf in the central part of the region received slightly deeper water sediments; the Mogollon inner shelf on the north and northeast was frequently emergent and received principally clastic deltaic sediments; and the Pedregosa basin in the southeast was rimmed with carbonate banks and shoals and its center, particularly during Late Pennsylvanian and Early Permian time, was the site of thick clastic sedimentation. Contemporaneous faulting locally accompanied major changes in lithofacies on the Mogollon shelf. A complicated set of faulted blocks separated the San Pedro outer shelf from the Pedregosa basin and diffe ences in times of deposition and erosion, thicknesses, and lithologies suggest that each fault block had an independent history of structural adjustment and sedimentary conditions.