Tectonic Evolution of the Bowen Basin, Eastern Queensland

The Permo-Triassic Bowen Basin developed during the final stages of the Tasman Orogenic Phase in eastern Australia. The basin has considerable economic value as a source of coal, natural gas and precious metals. The basin, which is of controversial origin, is preserved as a north-south trending, asymmetrical syncline bounded in places by faults. It is here interpreted as a retroarc foreland basin which developed on the landward (west) side of a continental arc associated with continent-ocean plate convergence. Initiation of the basin occurred via back-arc extension in Early Permian times, coincident with a phase of talc-alkaline arc volcanism. Early Permian, mostly marine sedimentation gave away to extensive coastal and alluvial plain depositional systems in Late Permian times, coincident with a resurgence of arc volcanism. Triassic sedimentation was almost entirely alluvial and coeval with westward propagation of thrust sheets from the eastern basin margin. Compressive tectonics climaxed in Middle to Late Triassic times, terminating sediment accumulation and uplifting the entire area.