The Cooper intracratonic sag basin of east-central Australia was formed by subsidence of parts of the Warburton Basin along the ancient zones of crustal weakness in the Late Carboniferous, about 285.5 million years ago (Krieg et al., 1990; Gravestock et al., 1995; Hill and Gravestock, 1995). This basin contains rocks of the Late Carboniferous to Middle Triassic which unconformably overlie the Warburton Basin and are also unconformably overlain by the Jurassic to Cretaceous Eromanga Basin. Locally, Upper Triassic rocks intervene. The structural configuration and sedimentation patterns were strongly controlled by Pre-Permian lineaments that continued throughout the history of the Permo-Triassic of the Cooper Basin (Hill and Gravestock, 1995).