Structural style of the Warburton Basin and control in the Cooper and Eromanga Basins, South Australia

Abstract

Deep-seated structures within the Warburton Basin have been intermittently reactivated during development of the overlying Cooper and Eromanga Basins. Four major deep structures preceding deposition of the Cooper Basin succession are described. 1) A complex deformation zone occurs on the eastern flank of the Birdsville Track Ridge near Kalladeina 1.2) Simple reverse faults are common and widespread in the Warburton Basin strata. 3) Gentle folds occur in the Coongie area and become increasingly tight towards the Birdsville Track Ridge. 4) Imbricate thrust faults form the cores of structures along the northeast-southwest trending Gidgealpa?Merrimelia?Innamincka Ridge. Warburton Basin structural control in the overlying basins is characterised by reactivation and propagation of thrust faults along the Gidgealpa?Merrimelia?Innamincka Ridge, and by further folding and faulting of the complex deformation zone on eastern flank of the Birdsville Track Ridge. The episodic, compressive reactivation has controlled depositional and erosional patterns of the Cooper and Eromanga Basins, and hence controlled hydrocarbon occurrence in these two basins. Potential footwall traps may be formed by propagation of the thrust faults.