Subsidence and Basin Development in the Southern Oklahoma Aulacogen

Abstract

Development of the southern Oklahoma aulacogen was the result of Cambrian tectonism along Proterozoic zones of weakness that caused northwest-trending extensional normal faults related to a rifting event. These faults were reactivated during upper Paleozoic compressional stress with fault patterns indicative of sinistral transpressive and transtensional movement. Mapping in the region has allowed classification of the myriad of faults into six major systems, from the north to south: the Washita Valley, Madill-Aylesworth, Caddo, Criner, Horseshoe Bend, and Muenster systems. Development of the fault systems occurred somewhat independently as energy was transferred between them owing to changes in stress from the uneven collision of the Ouachita front. This model may account for the episodic movement recognized by past investigators. The determination of relative timing of development within these systems has shown that the Madill-Aylesworth and Criner systems were active during the Upper Mississippian. As deformation continued along the Criner system structural activity moved southward to include the Horseshoe Bend and Muenster systems during the Early Pennsylvanian. During the Middle Pennsylvanian, fault development along the southern margin of the aulacogen subsided, and deformation activity was initiated in the northern portions of the Ardmore basin. The amount of horizontal displacement along fault systemsmore » in the region is still unresolved. However, by regional mapping along the Criner systems, a minimum of 6 mi left-lateral movement can be documented as having occurred during the Upper Pennsylvanian using models of sediment deposition and transport in strike-slip basins.« less