Archaean and Proterozoic diamond growth from contrasting styles of large-scale magmatism

Koornneef, J. M., Gress, M. U., Chinn, I. L., Jelsma, H. A., Harris, J. W. and Davies, G. R. (2017) Archaean and Proterozoic diamond growth from contrasting styles of large-scale magmatism. Nature Communications, 8, 648. (doi: 10.1038/s41467-017-00564-x) (PMID:28935863) (PMCID:PMC5608721)

Abstract

Precise dating of diamond growth is required to understand the interior workings of the early Earth and the deep carbon cycle. Here we report Sm-Nd isotope data from 26 individual garnet inclusions from 26 harzburgitic diamonds from Venetia, South Africa. Garnet inclusions and host diamonds comprise two compositional suites formed under markedly different conditions and define two isochrons, one Archaean (2.95 Ga) and one Proterozoic (1.15 Ga). The Archaean diamond suite formed from relatively cool fluid-dominated metasomatism during rifting of the southern shelf of the Zimbabwe Craton. The 1.8 billion years younger Proterozoic diamond suite formed by melt-dominated metasomatism related to the 1.1 Ga Umkondo Large Igneous Province. The results demonstrate that resolving the time of diamond growth events requires dating of individual inclusions, and that there was a major change in the magmatic processes responsible for harzburgitic diamond formation beneath Venetia from the Archaean to the Proterozoic.

• Item Type: Articles
• Additional Information: Council under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ ERC grant agreement no. 319209. J.M.K. received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 654208 (Europlanet 2020 RI).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Harris, Dr Jeff
• Authors: Koornneef, J. M., Gress, M. U., Chinn, I. L., Jelsma, H. A., Harris, J. W., and Davies, G. R.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Nature Communications
• Publisher: Nature Research
• ISSN: 2041-1723
• ISSN (Online): 2041-1723
• Copyright Holders: Copyright © 2017 The Authors
• First Published: First published in Nature Communications 8: 648
• Publisher Policy: Reproduced under a Creative Commons license