Trevorite: Ni-rich spinel formed by metasomatism and desulfurization processes at Bon Accord, South Africa?. (February 2014)

• Record Type: Journal Article
• Authors: O'Driscoll, B.; Clay, P. L.; Cawthorn, R. G.; Lenaz, D.; Adetunji, J.; Kronz, A.
• Is Part Of: Mineralogical magazine. Volume 78:Number 1(2014:Feb.)
• Page Start: 145
• Page End: 163
• Publication Date: 2014-02
• Subjects: trevorite, -- spinel, -- metasomatism, -- desulfurization, -- Bon Accord, -- South Africa; Mineralogy -- Periodicals; Mineralogy -- Great Britain -- Periodicals; 549.05
• DOI: 10.1180/minmag.2014.078.1.11
• Languages: English
• ISSNs: 0026-461X

Abstract

Abstract: The 3.5 Ga Bon Accord Ni deposit occurs within the lowest serpentinized mafic–ultramafic lavas of the Barberton Greenstone Belt (South Africa). Though now completely mined out, it comprised a suite of rare Ni-rich minerals that led to its interpretation as either an extraterrestrial body or as an oxidized fragment of Fe-Ni alloy originating from the terrestrial core. In this study, we draw on detailed petrographic observation and mineral chemical data, as well as previous work, to re-evaluate these ideas. The balance of evidence, from thin section (<1 mm) to regional (∼10s of km) scales, appears to support an alternative origin for Bon Accord, possibly as an oxidized Ni-sulfide deposit formed in association with ocean floor komatiite eruptions.