From Source to Sinks in Auriferous Magmatic-Hydrothermal Porphyry and Epithermal Deposits

Abstract

Auriferous porphyry Cu deposits are restricted to convergent plate settings, whereas epithermal precious metal deposits form at extending convergent plate settings and in rifts. Both deposit types are linked to magma carrying metals and ligands that rises to form an upper-crustal magma chamber. Magma convection and fractionation lead to volatile exsolution and collection in the apical parts of the chamber, from which exsolved hydrothermal fluid ascends to form either a porphyry Cu-Au deposit associated with stocks and dykes generally at 2-5 km depth, or an epithermal deposit associated with coeval volcanic rocks at depths of <1 km.