South Africa’s Witwatersrand goldfields are around 95% exhausted and production rates should fall permanently below 100 tonnes/year within the coming decade according to Dr Chris Hartnady, research and technical director of Cape Town earth sciences consultancy Umvoto Africa.



Dr Hartnady’s findings, based on Chamber of Mines figures and mathematical modeling pioneered by the distinguished American geologist M. King Hubbert, have appeared in the latest edition of the SA Journal of Science.



The South African residual gold reserve after production through 2007 is only 2 948 tonnes, a little less than three times the 1970 production figure, and much less than 10% of the officially cited reserve, says Hartnady.



The country’s gold reserves are less than half of the current United States Geological Survey (USGS) estimate of 6 000 tonnes, and the country is not first, but fourth in world rankings, after Australia (5 000 tonnes), Peru (3 500 tonnes) and Russia (3 000 tonnes), his research shows.



The USGS currently cites South Africa’s gold reserves at around 6 000 tonnes, while SA claims a 36 000 tonnes reserve base figure (or about 40% of the global total).



After the first (1880s-1910) and second stages (1911-1951) in the history of South African gold mining, there was “a remarkable growth phase” from an annual production rate of less than 400 tonnes in 1952 to over 950 tonnes in 1965.



This period is associated with bringing new mines into production around the new goldfields of Carletonville, Klerksdorp, the Free State and Evander areas, and the introduction of innovative technologies for mining at ever deeper levels.



“Given the energy and environmental problems associated with ongoing groundwater control, water-resource contamination by acid mine drainage and the possibility of widespread mercury and other factors of pollution caused by illicit underground ore-processing by the illegal miners, the glory days of South African gold mining appear to have arrived finally at an ignominious end.



“There can be no further illusions, maintained by unrealistic expectation of a future fortune, about the seriousness of the present situation. In their various possible forms, the slow-onset disasters of environmental degradation associated with the death-throes of a formerly illustrious industry now pose a serious threat , and may ultimately cost far more than the net present value of some 3 000 tonnes of gold,” says Hartnady.