Unveiling the metallogenic continuum of an Archean craton.

Abstract

The synchronous formation between 2675-2655 Ma of hydrothermal gold mineralisation in the Kalgoorlie and Kurnalpi Terranes and of magmatic sulfide mineralisation enriched in nickel, copper and platinum-group elements in the South West Terrane of the Archean Yilgarn Craton of Western Australia offers key insights into first-order controls on the genesis of mineral systems. Here we show that hydrothermal and magmatic deposits formed on opposite sides of this craton share four key features: timing, enrichment in incompatible chalcophile elements, positive Δ³³S sulfur isotope signatures, and links to hydrous, metasomatised lithospheric mantle. These commonalities challenge conventional models that treat such mineralised systems as unrelated. Instead, they point to a shared origin: a fertile lithospheric mantle reservoir enriched by crustal recycling, which was subsequently tapped to generate magmas and fluids anomalously endowed in volatiles and metals that migrated through the overlying lithosphere, punctually triggering ore formation. These findings support a unified mineral system model in which mantle processes exert a first-order control over metal endowment of Archean cratons.