Coal's Future Was Always Black

South Africa’s reliance on coal always had an expiry date on it – Tim Cohen examines why Eskom looks like it was left in the fridge too long

- Tim Cohen

When you talk about coal in South Africa, it’s always best to start with some maths. And history. And geology. And then, of course, there is politics.

The geology is complicated because the time period involved runs into billions of years, and since we still argue about the significance of the Boer War, it’s easy to imagine why it gets complicated pretty quickly. But if you dust away mountains of history and conjecture, the simplistic explanation is that a large chunk of what is now the northern bit of South Africa consisted about a billion years ago of an unusually large, unusually ancient piece of crystalline basement rock, called the Kaapvaal Craton.

Its comparative stability over the next billion years created the foundation for a huge array of metals to gradually deposit through weathering. At the centre of the craton, there was a lake (or possibly the sea), and the rivers into the lake gathered and concentrated metals from the weathering process. Amazingly we now know there were six rivers running into the depression. The result was a stunning array of reefs of different types, including of course, the famous gold reef which happened to jut out of the ground near Johannesburg.

This all happened way before the rinderpest. Actually, it was even before the dinosaurs. Over the years, these metal concentrations were jumbled about, pulled apart, and covered by volcanic activity. The result is a massively complicated geological heritage. But what remains are bits here and there of these reefs, including in Mpumalanga and northern KZN, of large chunks of coal.

HISTORY