Prominent Hill: a haematite-dominated, iron oxide copper-gold system.

The discovery of the mineralisation at Prominent Hill in the Mount Woods inlier in South Australia was based on an empirical exploration model which focused on the haematite end member of the lace ore deposit model type. Cu- and Au-bearing haematite-rich breccias were 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. Fe, Cu, Au, Ba, F, U, Ce and La are strongly correlated and associated with a relatively low temperature hydrothermal system. Mineralisation was synchronous with volcanism and sedimentation within a narrow east-west-trending graben that developed at about 1585 Ma.
The discovery of the mineralisation at Prominent Hill in the Mount Woods inlier in South Australia was based on an empirical exploration model which focused on the haematite end member of the lace ore deposit model type. Cu- and Au-bearing haematite-rich breccias were 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. Fe, Cu, Au, Ba, F, U, Ce and La are strongly correlated and associated with a relatively low temperature hydrothermal system. Mineralisation was synchronous with volcanism and sedimentation within a narrow east-west-trending graben that developed at about 1585 Ma.