We have constructed about 20 balanced structural cross-sections along the Frontal Ouachitas-Arkoma Basin transition zone between the Wilburton gas field and Wister lake, based on the wire line logs of 100's of wells, available seismic profiles, and surface geologic maps.

A well-developed triangle zone is present in the transition zone. It is flanked by the Choctaw fault to the south and the Carbon fault to the north. The footwall of the Choctaw fault contains a well-developed duplex structure. The Springer Detachment is the floor thrust and the Lower Atokan Detachment is roof thrust of the duplex structure. The roof thrust continues northward and displaces the Red Oak sandstone before reaching a shallower depth and forming the Carbon fault as a north dipping backthrust below the San Bois syncline. Northeast of the Wilburton field, the Carbon fault makes a lateral ramp to the east and becomes a blind backthrust. The triangle zone and the duplex structure are present throughout the transition zone from the Wilburton gas field to the Wister Lake area.

Southwest of Wilburton, the Main Choctaw fault forms a splay which is named here as the Northern Choctaw fault. The Lower Atokan Spiro sandstone is exposed on the hanging wall of the Main Choctaw. The fault wedge between the two faults contains no Spiro, suggesting that the Northern Choctaw is younger than the Main Choctaw. This indicates a break-forward thrusting between the two faults and implies that the imbricate thrusts on the hanging wall of the Main Choctaw were also developed by the same mechanism.