Ancient rivers filled with gold, a spectacular upwelling of magma and a colossal meteor impact combined to make the Witwatersrand basin a very special place
In 1885 two itinerant workers discovered a surface outcrop of gold on a farm in what is now Johannesburg. In what must be one of the biggest financial blunders in history, both men soon sold their claims for a few hundred dollars. In today's dollars, the gold fields in the region are now worth many billions. In fact, this part of South Africa, which covers an area the size of West Virginia, contains almost as much gold as the rest of the Earth's surface combined. How did South Africa become so rich in this element? Jason Kirk and his colleagues recently answered this question by solving a 100-year-old geologic mystery.