The Yilgarn Retrospective 1950–99 Symposium

The Yilgarn Craton (Western Australia) forms a large part of inland central and southern Western Australia. It hosts gold mines in the Kalgoorlie to Wiluna area, at Norseman, Meekatharra and Boddington; nickel from Ravensthorpe to Kambalda and Leinster; bauxite (aluminium) ores in the Darling Range; copper–zinc at Golden Grove; tantalum at Greenbushes; iron ore at Koolyanobbing; and uranium at Yeelirrie. In the second half of the twentieth century, the Yilgarn witnessed a transformative period in the resources industry which included the discovery and successful exploitation of a new deposit type (komatiite-hosted nickel sulphide), a massive boom in the exploration and mining of Archaean lode gold, and developments in a number of other commodities. By 1999, 20 million tonnes of nickel had been identified, and the gold inventory rose in 20 years from 4 million ounces to 100 million ounces, despite the mining of about 100 million ounces over the same period. Nickel production reached 170 000 tonnes per annum and gold production was ∼6.5 million ounces per annum. Western Australia was converted from a small economy based largely on agriculture to the world’s mining powerhouse. These commercial successes were a culmination of research yielding new deposit models, a new appreciation of the regolith that blankets the Yilgarn and the tools to work beneath that regolith.