Geological investigations carried out on the Babbage Peninsula at the southern end of Lake Eyre North suggest that an estimated 250 million tons of dolomite, with little or no overburden, is available for mining, and that additional reserves are present in this area beneath a cover of wind-blown sand. The dolomite occurs as essentially flat-lying and porous beds, and lake edge cliff exposures which were sampled for chemical analysis indicate a deposit thickness of 10 feet averaging almost 19% MgO. Petrological studies show that the sedimentary rock has a grain size of 2-3 microns, with the most abundant impurity being clay, which tends to be disseminated in low concentration as extremely small particles. Other mineral impurities such as gypsum, quartz, mica, etc. are present in trace amounts only.