Diverse sources of sulfur in Archean ore deposits of the southwest Yilgarn Craton, Western Australia

Abstract

Multiple sulfur isotopes (δ³⁴S, δ³³S, δ³⁶S) are powerful tracers of sulfur reservoirs and fluid evolution in mineral systems, especially in granulite-facies terranes where conventional geochemical indicators may be overprinted. The Yilgarn Craton is one of the most gold-rich Cratons in the world. This study applies in situ secondary ion mass spectrometry (SIMS) to analyze sulfur isotopes in sulfide minerals from a range of Archean mineral deposits in the southwest Yilgarn Craton, Western Australia—including seven metamorphosed gold deposits, and nearby intrusion-related and volcanic-hosted massive sulfide (VHMS) systems. The results reveal systematic differences in Δ³³S values across deposit types. Intrusion-related and some VHMS deposits display near-zero Δ³³S values, consistent with sulfur derived from a primitive mantle source and limited crustal input. In contrast, metamorphosed gold deposits exhibit a broader range of Δ³³S values, reflecting mixed contributions from mantle-derived fluids and Archean sedimentary sulfur, including both sulfide- and sulfate-dominated reservoirs. These findings highlight the utility of multiple sulfur isotopes for fingerprinting sulfur sources and fluid processes in high-grade metamorphic terranes. The data underscore the diversity of sulfur reservoirs accessed by different mineral systems and offer a geochemical framework for interpreting metallogenic processes in the southwest Yilgarn Craton.