Diamond drilling of the Mutooroo copper prospect located near Cockburn in South Australia has outlined probable ore reserves of 9.2 million tonnes at 1.7% copper. The ore is massive sulphide and there are no associated metal values (e.g. silver, gold, etc.). The subject economic study considers a proposal for mining the deposit, using conventional mining and ore treatment techniques, over a period of ten years to depletion. The mine production rate would be 1,000,000 tonnes per annum at a grade of 1.5% copper after allowing 10% mining dilution, and yielding 56,000 dry tonnes per annum of concentrate containing 25% copper. Current cost estimates show that a capital investment of $45 million would be required to bring the deposit into production. This figure includes $6.6 million for a township to house 470 employees and their dependants. Annual operating costs are estimated at $1300 per tonne of copper contained in the concentrate product. This estimate includes distribution costs and smelter charges, but excludes taxation, royalties, depreciation and financing charges. The current market price for copper is $900 per tonne. The copper price at which the project would break even, operating at full capacity, and excluding interest charges and royalties, is $1600 per tonne. This price has been exceeded on the London Metal Exchange only for a short period from December 1973 to June 1974. A significantly higher copper price would be required if the project is to break even at less than full capacity. At present there appears to be little likelihood that prices will reach the levels necessary for economic exploitation using conventional technology.