NEARLY 60 per cent of the world’s gold comes from rocks formed during the Archean eon, which ended 2.5 billion years ago. Now it seems that seismic activity in bends in ancient fault lines produced the mysteriously high concentrations of gold in some of these deposits.
David Groves of the University of Western Australia in Crawley and his colleagues traced the distribution of gold fields along an ancient fault zone in Western Australia. They found that four of the richest known gold deposits, including the 1800-tonne giant Golden Mile at Kalgoorlie, occur at regular intervals of 30 to 40 kilometres…
