ABMINGA lies on the eastern edge of the Musgrave Block, which consists of Early to Middle Proterozoic gneisses and granites, intruded by dolerite dykes. A small area of folded and faulted Adelaidean and Cambrian sediments lies in the SW corner. Mesozoic freshwater and marine sediments of the Eromanga Basin lap onto the older rocks from the east, and are overlain by Cainozoic units, mainly silcrete and surficial sand spreads. Drilling and geophysical data indicate that a Palaeozoic sedimentary sequence underlying the Eromanga Basin in the east. This sequence ranges in age from Cambrian (Warburton Basin) to Carboniferous - Permian (Pedirka Basin), and it thickens considerably to the east, where the depth of magnetic basement is estimated at 3.5 km. The main structural highs are the Musgrave Block and the Bitchera Ridge, the latter composed predominantly of Adelaidean rocks. The Moorilyanna Graben, which is filled with a thick sequence of Adelaidean sediments, lies between these highs. There is exploration potential for coal in the Pedirka Basin, and for hydrocarbons in the untested Palaeozoic sequence in the east.