The Early Ordovician to Early Cretaceous pericratonic Canning Basin occupies about 506,000 sq km, of which 430,000 sq km are onshore Western Australia. Late Cretaceous and Tertiary sediments are restricted to the offshore portion of the basin and pinch-out landward. The basin has a maximum sediment thickness of over 15 km concentrated in two NW trending depocentres. The northernmost of these is the Fitzroy Trough-Gregory Sub-basin complex, while the southernmost is the Willara Sub-basin - Kidson Sub-basin complex. The Fitzroy trough continues offshore.
Deposition in the basin commenced during an Early Ordovician phase of extension and rapid subsidence. Rifting was followed by a prolonged sag stage characterised by widespread evaporitic and playa conditions in the Late Ordovician and Silurian.
The second basin phase was initiated by minor folding, regional uplift and erosion in the earliest Devonian and embraces laterally extensive aeolian and terrestrial deposits.
The third phase incorporates major extension, rifting and rapid subsidence in the mid-Devonian. The sag stage following this extension was interrupted by at least two extensional tectonic pulses marked by influxes of conglomerates along the northern margins of the basin.
The fourth basin phase was initiated by mid-Carboniferous compression and inversion of Devonian normal faults and is marked by syntectonic fluvial deposits.
The fifth phase is marked by renewed extension and rapid subsidence, coinciding with the onset of glacial conditions in the Early Permian and incorporates a sag stage with widespread transgression following the glaciation.
The final tectonic phase was triggered by regional dextral wrench movements in the Late Triassic - Early Jurassic when up to 3 km of uplift and erosion occurred, accompanied by extensive molasse deposition. This was followed by deposition of fluvio-deltaic and marine sediments.
Only 250 wells have been drilled and 78,000 km of seismic shot. Production is currently from Permo-Carboniferous sandstones (Lloyd, Sundown, etc) and Devonian carbonates (Blina) with many shows in Ordovician-Permian section. Proven plays include draped bioherms, anticlinal closures and tilted fault blocks. Untested plays include unconformities, fault rollovers, diapirs and stratigraphic traps.