Journal article
Provenance history of detrital diamond deposits, West Coast of Namaqualand, South Africa
D Phillips, JW Harris, MCJ de Wit, EL Matchan
Mineralogy and Petrology | SPRINGER WIEN | Published : 2018
Abstract
The West Coast of Namaqualand in South Africa hosts extensive detrital diamond deposits, but considerable debate exists as to the provenance of these diamonds. Some researchers have suggested derivation of the diamonds from Cretaceous-Jurassic kimberlites (also termed Group I kimberlites) and orangeites (also termed Group II kimberlites) located on the Kaapvaal Craton. However, others favour erosion of diamonds from the ca.300 Ma Dwyka Group sediments, with older, pre-Karoo kimberlites being the original source(s). Previous work has demonstrated that 40Ar/39Ar analyses of clinopyroxene inclusions, extracted from diamonds, yield ages approaching the time(s) of source kimberlite emplacement, w..
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Funding Acknowledgements
We are indebted to the De Beers Group for donation of the Namaqualand diamonds, logistical and financial support, and permission to publish. We are especially indebted to Verlece Anderson, Gillian Parker and Edna van Blerk, of Harry Oppenheimer House in Kimberley, for selection of clinopyroxene-bearing diamonds. We thank Stan Szczepanski for technical assistance in the University of Melbourne <SUP>40</SUP>Ar/<SUP>39</SUP>Ar analyses. We acknowledge the constructive comments by the two reviewers (Steven Shirey and Ray Burgess) of the manuscript, and the editorial handling of Thomas Stachel.