Empirical observations on granite-associated gold ± base-metal mineral deposits in the Proterozoic of Australia

Abstract

In the Proterozoic of Australia, hydrothermal vein- and breccia-hosted Au ± base-metal mineral deposits are rarely hosted by granites (their supposed sources), and commonly occur in country rocks up to 5 km from the nearest pluton boundary. A review of field, petrographic, and geochemical characteristics of both granites and host rocks associated with such deposits shows many common features. The granites are all chemically fractionated and have specific geochemical characteristics, and the Au host rocks usually contain a reductant such as carbonaceous matter, sulphides, or magnetite. The granites and host rocks of such deposits are distinct from those usually associated with porphyry Cu ± Au ± Mo and carbonate-rich skarn deposits. -Authors Show more