Potentially large, poorly-defined resources of black coal buried at the south-western and southern margins of the Cooper Basin were investigated via a review of relevant previous petroleum exploration geological and geophysical data. Probable thick, high quality seams at an indicated depth of >1000 m were targeted, but it was decided to surrender tenure when the company considered the economic implications of conducting deep underground mining in a region where geothermal gradients can be as high as 7.2 degrees Centigrade per 100 m depth.