Mining Mirror February 2019 | Page 45

Lessons from the past Basin specialists, are familiar with the great debate and the heated discussions about placer gold, hydrothermal sources, and a combination of the two, called modified placer-theory. We haven’t seen too many drill rigs searching for gold deposits in the Karoo lately — it’s about time we do. For once, we should listen to and believe in geologists. Contrary to widespread belief, gold mining is not a sunset industry in South Africa; in fact, its rebirth might be imminent. I conclude with an excerpt from an article written by three legendary South African geologists: twin brothers Morris and Richard Viljoen and Rodney Tucker. Although the Witwatersrand is a mature goldfield with declining production, it is estimated that it still contains six times more gold than the world’s second-largest goldfield. Much of the remaining resource occurs at considerable depths; however, there are still opportunities for extracting some of this resource, as well as generally somewhat lower-grade mineralisation, at moderate to shallow depth. The Basin thus remains a major exploration target. The article “A review of the Witwatersrand Basin – the world’s greatest goldfield” was authored by Rodney F. Tucker; Richard P. Viljoen, and Morris J. Viljoen, and appeared in the June 2016 issue of Episodes Journal of International Geoscience (Vol. 39 No. 2, titled: The great mineral fields of Africa). Basin specialists, are familiar with the great debate and the heated discussions about placer gold, hydrothermal sources, and a combination of the two, called modified placer-theory. Most placer-theory proponents believe that the Witwatersrand gold was deposited in a shallow marine environment (the Basin). But a group of alternative thinkers believes that the gold was deposited by ice age glaciers — this could open a whole new world for geologists, gold miners, and explorers in South Africa. www.miningmirror.co.za If gold had been transported by glaciers, it could have been deposited much further south than what is currently believed. According to the glacier theorists, another gold basin exists, covering a large area of the Great Karoo, but has not yet been discovered. This idea is dismissed too often and should receive more attention. A lack of funding, regulatory and political constraints, and rising costs have prevented exploration companies from taking on the risk and venturing into unknown territory. In the March 2019 editions of African Mining and Mining Mirror, several top geologists share their views about the history, geology, and potential of both the Witwatersrand Basin and the gold mining industry in South Africa. Make sure you get your copies. FEBRUARY 2019 MINING MIRROR [43]