The CALLABONNA map area includes the southern end of the Strzelecki Desert and the north- eastern Flinders Ranges, between latitudes 29° to 30° S and longitudes 139° 30' to 141° E. Cameron Corner adjoins New South Wales and Queensland in the north-east. Two large ephemeral drainage sinks form Lakes Blanche and Callabonna. Strzelecki Creek derives from the Cooper Creek (further north) and terminates in Lake Blanche. This area is broadly flat to slightly concave and is predominantly covered by longitudinal NE to north trending seif sand dunes. The Flinders Ranges (SW map corner) form highlands within this region. They are composed of highly deformed Palaeoproterozoic metasediment rafts and keels floating on variably deformed Mesoproterozoic granitoids and volcanics. Folded Neoproterozoic rocks of the sedimentary Adelaide Geosyncline unconformably overlie the older crystalline basement. The surrounding plains are underlain by sediments of the Cambro-Ordovician Arrowie and Warburton Basins along with the Carboniferous-Permian Cooper Basin, the Mesozoic Eromanga Basin, and the Cainozoic Lake Eyre Basin and Callabonna Sub-basin. Crustal deformations occurred during the Olarian Orogeny (1670-1590 Ma), mafic dykes were injected during tensional stress (~1100-800 Ma), and Adelaide Geosyncline sediments were folded and intruded by granitic plutons during the late Delamerian Orogeny (400 m. Mapping, petrography and geochemistry have helped define 102 distinct rock units from this area. Prospecting and exploration undertaken since 1870 have located arsenic, cobalt, copper, lead, molybdenum, rare earth element (REE), tin, uranium, tungsten and zinc mineralisation, along with trace gold and silver. Non-metallic extractive minerals found have included talc, dolomite, magnesite, muscovite, celestite and fluorite. Mining carried out over the last hundred years has extracted copper, talc, dolomite and muscovite. Groundwater is a valuable commodity and is widely exploited by pastoralists, stock and wildlife. A significant amount is drawn from the Eromanga Basin and Lake Eyre Basin aquifers. Artesian groundwater flows naturally to the surface via mound springs (natural desert oases) or flows there artificially through boreholes penetrating into the Eromanga Basin. Many such water bores were drilled between 1890 and the 1960s. There is potential for geothermal energy exploitation in this area due to a high thermal flux, partly generated by crystalline basement containing unusually abundant REEs, and partly by a regionally high crustal heat flux. Fossils found on CALLABONNA include poorly preserved Neoproterozoic stromatolites and trace fossils from the Cambro-Ordovician. Shelly fauna, trace fossils, carbonaceous flora and coal have been recovered from the Cooper and Eromanga Basin sequences. The Mesozoic Neales River Group commonly contains abundant shells, calcified wood and many animal burrows. Leaf impressions and animal burrows, bones and teeth occur within the lower to middle Cainozoic units but are not common. Quaternary units have yielded some spectacular bones from the once abundant Australian Megafauna. These finds came mostly from the Lake Callabonna Fossil Reserve and include the largest pouched marsupial, Diprotodon sp., and a giant emu-like flightless bird - Genyornis newtoni.