The geology is controversial and complex. It consists of a concentric series of uplifted deformed Palaeozoic and Mesozoic rocks capped by flat-lying Cainozoic deposits. The rocks at the centre of the uplift are highly deformed Mt. Toondina Formation (Permian) surrounded by a ring of less deformed Algebuckina
Sandstone (Jurassic), and Cretaceous Cadna-owie Formation and Bulldog Shale. The Algebuckina
sandstone is the main aquifer of the Great Artesian basin and discharging springs in this unit had deposited flat-lying travertines, remnants of which make up the modern topographic feature. The area of geophysical disturbance about Mt. Toondina suggests the structure is about 4 km across. The structure has been variously described as a diapir and an impact structure.
The structure was first mapped in 1964.There were extensive geophysical exploration using gravity and seismic surveys, as part of a petroleum exploration program.
The area is not rugged but is remote and difficult to access.The area should not be visited without two vehicles and appropriate supplies of water food, and good communications and emergency procedures.