Maiya Dalton, BSc
M. Dalton1, B. O'Driscoll1
1Department of Geology, University of Ottawa, Ottawa, Ontario, Canada
The Bon Accord nickel deposit was hosted in ~3.5 Ga ultramafic-mafic rocks of the lowermost Onverwacht Group of the Barberton Greenstone Belt, South Africa. Although mined out a century ago, its extremely unusual Ni-rich mineral assemblage and abnormally high NiO content (~15 wt.%) have led to multiple petrogenetic interpretations, including an extraterrestrial origin or an oxidized fragment of Earth’s outer core. A more recent study proposed the formation of the Bon Accord as an altered (komatiite-hosted) nickel-sulfide deposit, based on the presence of such mineralization in close proximity that can be stratigraphically and structurally correlated with the Bon Accord. Here, we undertake a petrographic and chemical analysis of spinel minerals in a sample of the Bon Accord body, as well as spinels associated with the nearby sulfide mineralization, to evaluate whether a petrogenic relationship exists between both and if the sulfide mineralization is a plausible precursor to the unique Bon Accord paragenesis.