The Permian basin of west Texas and southeastern New Mexico probably originated in late Precambrian time as a shallow geosynclinal trough on the southern edge of the North American craton. The extreme southern part of the region formed part of a subduction trough.

By Late Cambrian time the seas in the southern part of the trough had advanced over part of the craton, and Paleozoic sedimentation began. Perhaps in late Precambrian a north-facing salient of the trough developed into an aulacogen with lateral dextral movement along steep faults in what later became the eastern part of the Delaware basin.

During early and middle Paleozoic time the region was tectonically quiet. However by Middle Mississippian the Precambrian zones of weakness were reactivated and the Delaware and Midland subbasins began to form. At the same time the Marathon-Ouachita trough began to deepen.

In early Middle Pennsylvanian time active tectonism with stresses from the northeast formed a small mountain chain between the two subbasins, on the site of the Central Basin platform. In later Pennsylvanian and Early Permian time renewed tectonism resulted in low-angle thrusting of early Paleozoic rocks northward from the Marathon trough. At the same time there was renewed vertical movement on the ancient lateral faults which formed the eastern edge of the Delaware basin.

Middle and Late Permian was a quiet time tectonically with the only movement being slight subsidence, probably due to differential compaction in the basins. This regime continued through the early Mesozoic. By Early Cretaceous, however, a major change in paleogeography resulted in an advance of the sea over the region which was by then securely welded to the craton.

The area was protected from severe deformation during the Laramide orogeny by the beam effect of the Matador and Amarillo uplifts on the north and the east-west folds of the Marathon belt on the south. Tectonic activity since the early Tertiary has been minimal.

Tectonic style in the Delaware basin is characterized by eastward tilt in the Permian and younger rocks. The older rocks are folded and cut by steeply dipping faults. The Central Basin platform style comprises supertenuous draped structures in the younger rocks. These overlie closed folds with steeply dipping faults in the older rocks which trend north-northwest. The Midland basin contains en echelon faults and extension fracturing, reflecting moderate movement. The extreme southern part of the Permian basin consists of deep folded troughs bounded by thrust faults. The trend of these structures forms a large angle with the trends of the Central Basin platform.

The long interval of tectonic stability in the region since the early Permian has undoubtedly contributed to the maturation and accumulation of the oil and gas resources of the basin.

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