Staged formation of the supergiant Olympic Dam uranium deposit, Australia

Abstract The origins of many supergiant ore deposits remain unresolved because the factors responsible for such extreme metal enrichments are not understood. One factor critical importance is timing mineralization. However, information commonly confounded by difficulty dating minerals. world's largest uranium resource at Olympic Dam, South Australia, exceptional high abundance U allows U-Pb Dam U(-Cu-Au-Ag) deposit hosted in ca. 1.59 Ga rocks, and consensus has been that formed same time. We argue that, fact, two stages mineralization were involved. Paired situ trace element analyses texturally distinct uraninite populations show size highest-U-grade zones result addition 0.7–0.5 Ga, least one billion years after initial formation. This conclusion supported a remarkable clustering thousands radiogenic 207Pb/206Pb model ages Cu sulfide grains this Upgrading original to its present may have resulted from perturbation regional fluid flow triggered global climatic (deglaciation) tectonic (breakup Rodinia) events.