Trevorite: Ni-rich spinel formed by metasomatism and desulfurization processes at Bon Accord, South Africa?

Year:

2014

Type of Publication:

Article

Authors:

O', B.; Driscoll, ; Clay, P. L.; Cawthorn, R. G.; Lenaz, D.; Adetunji, J.; Kronz, Andreas

Journal:

Mineralogical Magazine

Volume:

78

Number:

1

Pages:

145-163

BibTex:

@article{O'Driscoll01022014, author = "B. O{\&}#039 and Driscoll and P. L. Clay and R. G. Cawthorn and D. Lenaz and J. Adetunji and Andreas Kronz", abstract = "The 3.5 Ga Bon Accord Ni deposit occurs within the lowest serpentinized mafic{\^a}€“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 ({\&}amp;lt;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.", doi = "10.1180/minmag.2014.078.1.11", journal = "Mineralogical Magazine", number = "1", pages = "145-163", title = "{T}revorite: {N}i-rich spinel formed by metasomatism and desulfurization processes at {B}on {A}ccord, {S}outh {A}frica?", url = "http://minmag.geoscienceworld.org/content/78/1/145.abstract", volume = "78", year = "2014", }

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.