Provenance studies from Ar-40/Ar-39 dating of mineral inclusions in diamonds: Methodological tests on the Orapa kimberlite, Botswana

Abstract

Previous studies indicate that clinopyroxene inclusions extracted from their host diamonds give 40Ar/39Ar ages approaching the time of source kimberlite eruption. This behaviour is attributed to diffusion of argon to the diamond/inclusion interface region during mantle residence, with subsequent loss of this component on cleaving of the diamond to release the inclusion(s). In this study, we investigate the potential of the 40Ar/39Ar inclusion dating method as a niche provenance tool. As diamondiferous kimberlites are uncommon igneous rocks, largely restricted to Archaean cratons and have limited age ranges, provenance studies of detrital diamond occurrences should provide unique information ..