Basin modeling, structural evolution, and hydrocarbon source rock thermal maturation in the Ardmore Basin, southern Oklahoma

This study analyzes two dimensional (2D) seismic profiles and well logs to examine the subsurface of the Ardmore Basin in southern Oklahoma, focusing on the hydrocarbon-rich Harrisburg Trough and Berwyn Syncline. The basin’s complex structure results from multiple orogenic events and associated phases of subsidence. During the Cambrian–Ordovician, thermal subsidence resulted in flat-lying stratigraphy. Seismic data provide little evidence linking the basin to an extensional aulacogen; instead, right-lateral oblique-slip appears more likely. Major faults, such as the Healdton Fault, appear to be rooted in an Iapetan mid-crustal detachment. Deformation in southern Oklahoma was influenced by far-field stresses from Appalachian orogenies, reactivating shear zones. The earliest deformation was reverse faulting in the Middle–Late Ordovician, likely driven by the Taconic Orogeny. Significant structural changes began in the Late Devonian with the First Wichitan Orogeny, related to stresses from the Rheic Ocean and Acadian Orogeny. Devonian–Pennsylvanian time was marked by synsedimentary growth of oblique-slip faults and folds. By the Late Pennsylvanian, deformation had largely ceased, save for minor left-lateral faulting linked to the Arbuckle Orogeny. Post-Permian tectonic activity was minimal, with no Triassic or Jurassic strata preserved. Cretaceous strata, preserved in the southeast, record tilting related to the Gulf of America Basin. This study presents the first modern basin modeling of the Ardmore Basin, using 12 burial history models in addition to a 2D model of the Harrisburg Trough to assess the thermal maturity of Woodford and Caney shale. The models reveal episodes of subsidence and uplift influenced by major tectonic events. Rapid Late Mississippian–Permian subsidence (>250 m/m.y.) suggests elevator basin behavior. Thermal maturity (0.4–2.0% Ro) varies by structural position, with deep synclines having higher thermal maturity than shallower structures. Basin modeling confirms burial depth and heat flow influenced hydrocarbon generation. The Woodford Shale in the Harrisburg Trough acted as a thermal insulator, enhancing thermal maturity. The Carboniferous thermal pattern was synkinematic and became post-kinematic in the Permian.