Evaluating the lithospheric architecture of the Archean Yilgarn Craton in space and time: implications for komatiite volcanism and earth evolution

[Truncated] Komatiite-hosted nickel-sulphide deposits in Archean granite-greenstone terranes of the Yilgarn Craton of Western Australia are a major source of the world’s nickel, with world-class deposits generally occurring in clusters (camps). In the Southern Cross Domain (Youanmi Terrane), komatiites and their associated nickelsulphide deposits were emplaced at ca. 2.9 Ga. In the south of the domain, the komatiites of the Lake Johnston, Forrestania and Ravensthorpe greenstone belts contain nickel-sulphide deposits (e.g. Flying Fox, Maggie Hays), whereas komatiites in the central and northern areas are currently unprospective. In the Kalgoorlie Terrane of the Eastern Goldfields Superterrane, mineralised komatiites were largely emplaced at ca. 2.7 Ga. In the northern Kalgoorlie Terrane, the Agnew-Wiluna greenstone belt is the most highly nickel endowed komatiite belt in the world. It contains two world-class nickel deposits, Mount Keith and Perseverance, and numerous economic deposits such as Yakabindie, Waterloo, Cosmos-Alec Mairs, Sinclair, Tapinos, Prospero, Cliffs, Rocky’s Reward-Harmony, and 11 Mile Well.

By integrating regional data with studies of key nickel deposits and camps, this study has developed a superior metallogenic model to help target areas of high prospectivity for komatiite-hosted nickel-sulphide deposits. The approach was based on an improved understanding of the four dimensional evolution of the stratigraphy and lithospheric architecture of the Yilgarn Craton. The metallogenic model is potentially applicable to exploration in Archean terranes worldwide.