Prominent Hill: A Hematite-Dominated, Iron Oxide Copper-Gold System

摘要

The discovery of iron oxide copper-gold (IOCG) mineralization at Prominent Hill in the Mount Woods inlier (South Australia) by Minotaur Resources Ltd. in November 2001 was based on an empirical exploration model that focused specifically on the hematite end member of the IOCG ore deposit model type. Copper and gold-bearing hematite-rich breccias formed by repetitive hydrothermal brecciation, milling, and explosive venting within a volcanic setting. High-pressure spalling, chemical corrosion of breccia clasts, and compositional layering within the breccias are distinctive features. Iron oxide-sericite-silica alteration is pervasive within and marginal to the main breccias and is surrounded by a wider zone of less intense alteration. Iron, copper, gold, barium, fluorine, uranium, cerium, and lanthanum are strongly correlated and associated with a relatively low temperature hydrothermal system. Mineralization was synchronous with volcanism and sedimentation within a narrow east-west-trending graben that developed at approx 1585 Ma.