The Cultana 3D Geological Model covers an area which includes the Roopena and western half of the Cultana 1:100,000 map sheet areas. The geology of the model area comprises a succession of deformed Palaeoproterozoic sedimentary and intrusive rocks which are overlain by the Corunna Conglomerate and Mesoproterozoic Gawler Range Volcanics and intruded by the Hiltaba Suite granites. In the east of the model area the Gawler Craton basement is overlain by a sequence of Neoproterozoic sediments and volcanics of the Stuart Shelf. These sediments have been eroded from the uplifted block of the Cultana Inlier, to expose the basement below.