Metallogenic characteristics and ore-control factors of the high-grade BIF of the Hamersley iron province in western Australia

The Hamersley iron province of Western Australia contains the world-class high-grade hematite deposits hosted within the Lower Proterozoic Brockman Iron Formation （BIF-type） in Mount Tom Price, Mount Whaleback, and Paraburdoo. Spatially, these deposits are structurally constrained by old normal fault systems formed during a period of major uplift and extension in Proterozoic. The formation of the Hamersley high-grade hematite deposits could be divided into three stages, i.e. the first stage or the hypogene metallogenic stage, during which silica was removed, leaving thinned residues rich in iron oxides, carbonates, magnesium silicates and apatite; the second deep meteoric stage, during which magnetite-siderite assemblage was oxidized into hematite-ankerite; the third stage or the supergene stage. Based on a discussion on the metallogenic characteristics and the ore genesis model, the authors have found that the ore-forming epochs, the tectonic characteristics such as faults and folds, fluids, and the supergene weathering constituted the main ore-control factors for the formation of the high-grade iron deposits.