Macroscopic structural styles in the southeastern Anadarko Basin, southern Oklahoma

Abstract

The Anadarko Basin in south-central Oklahoma contains a number of oil and gas fields located on anticlinal structures formed during the Pennsylvanian Orogeny. We use new 2-D and 3D seismic and well data to interpret the structural geometry and kinematic evolution of the Carter-Knox, Cruce, Chickasha, and Cement structures. These structures consist of tight faulted-detachment folds within the Pennsylvanian units related to slip along a detachment at the base of the Springer Shale, cored by deeper low amplitude fault-related folds within the pre-Pennsylvanian thick carbonate units which are detached at the base of the Arbuckle Group. Slip on these detachments was derived from the Wichita Uplift, which was a Precambrian-Cambrian failed rift that became inverted during the Pennsylvanian Orogeny. The trend and location of these structures was probably controlled by discontinuities related to pre-existing rift-related basement normal faults.Variations in the structural styles among the major structures are related primarily to the shortening and the influence of late-stage normal/strike-slip faulting. Changes in shortening are manifested in the increasing tightness and relief of the anticlines from the Chickasha-Cement to the Carter-Knox and Cruce structures. Some of the E-W structures were cut by Virgilian age strike-slip and associated normal faults which formed as the maximum compressive stress rotated from NE-SW to ENE-WSW during the Late Pennsylvanian. In summary, the geometry, trend, and evolution of the structures were influenced by the mechanical stratigraphy, pre-existing basement structures, and a rotation in stresses during the final stage of their formation.