Alkaline magmatism as a probe into the evolution of the lithospheric mantle in the Yilgarn Craton, Western Australia

The Challenge

Deep-seated magmas are key to the development of nickel sulfide and other valuable ore minerals in the Yilgarn. New approaches to analysing the chemistry of these ancient magmatic rocks could help us understand how this region evolved its phenomenal mineral endowment.

Key Findings

• Some areas of the Yilgarn were enriched in gold and easily-mobilised chemical components by a now-vanished oceanic plate as it was dragged deep into the mantle below the region.
• This ancient enrichment was an important contribution to the later development of rich gold mineralisation, and its distribution correlates strongly with the location of major gold deposits in the Yilgarn.
• Chemical markers of this fundamental fertility can be detected in deep-seated igneous rocks derived from enriched mantle areas.

Benefits to WA

Eunjoo’s research is helping scientists understand the potential of the Yilgarn province to host further as-yet undiscovered ore bodies, and recognise the chemical clues that might point to their hidden presence. These insights will support mineral exploration companies working to discover the next generation of mines in WA.

Keywords: Alkaline magmatism; mineral systems; mantle; Yilgarn Craton