The KIMBA 1:250 000 geological map sheet (hereafter referred to as KIMBA) lies in central Eyre Peninsula, extending between latitudes 33° to 34° S and longitudes 135° to 136°30'E (Fig 1). The principal towns are Kimba and Cleve, with smaller towns at Wudinna, Kyancutta, Lock, Rudall, Darke Peak, Pygery and Warramboo. The area is crossed by the Eyre Highway in the north, the Flinders Highway along the west coast, the Lincoln Highway on the east coast, and the Ceduna-Port Lincoln and Buckleboo-Cummins railways. The area has been extensively cleared for agriculture, particularly rotation cereal cultivation and livestock grazing. Major cereals are wheat and barley, and sheep are the most important livestock. Large tracts of native vegetation still exist, especially in the Pinkawillinie, Hambidge, Bascombe Well, Hincks and Carappee Hill Conservation Parks. Mapping of KIMBA was based on Department of Lands 1981 black and white and colour aerial photos on a scale of 1:40 000. Geological boundaries were transferred to 1:100 000 topographic base maps which are available from SADME as black and white paper prints. Final compilation at a scale of 1:250 000 entailed some simplification of boundaries.