Journal article

Isotopic analyses of clinopyroxenes demonstrate the effects of kimberlite melt metasomatism upon the lithospheric mantle

Angus Fitzpayne, Andrea Giuliani, Janet Hergt, Jon D Woodhead, Roland Maas

LITHOS | ELSEVIER | Published : 2020

Abstract

The trace element and radiogenic isotope systematics of clinopyroxene have frequently been used to characterise mantle metasomatic processes, because it is the main host of most lithophile elements in the lithospheric mantle. To further our understanding of mantle metasomatism, both solution-mode Sr-Nd-Hf-Pb and in situ trace element and Sr isotopic data have been acquired for clinopyroxene grains from a suite of peridotite (lherzolites and wehrlites), MARID (Mica-Amphibole-Rutile-Ilmenite-Diopside), and PIC (Phlogopite-Ilmenite-Clinopyroxene) rocks from the Kimberley kimberlites (South Africa). The studied mantle samples can be divided into two groups on the basis of their clinopyroxene tra..

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Grants

Awarded by Swiss National Science Foundation


Funding Acknowledgements

We thank Alan Greig for his help during solution and in situ trace element analyses, Graham Hutchinson for his assistance during EPMA analytical sessions, Serene Paul for her support with sample preparation for isotopic analyses, Yoann Greau and Bill Griffin for providing fragments of Batbjerg clinopyroxene, and Wenyue Zhou for her assistance during data acquisition. De Beers Consolidated Mines, the J.J. Gurney Upper Mantle Collection at the University of Cape Town, and Simon Shee provided access to the studied samples, for which we are extremely grateful. We also thank Jock Robey for his assistance during fieldwork in the Kimberley region. The data collection for this study was carried out during AF's PhD studies, whichwere supported by a Gilbert Rigg scholarship from the University of Melbourne; writing of this manuscript was conducted with the financial support of the Albert Shimmins Fund from the University of Melbourne and the Ambizione fellowship awarded to AG by the Swiss National Science Foundation (grant n. PZ00P2_180126/1). This is publication 57 fromthe Kimberlites and Diamonds Research Group (https://kimberlitesdiamonds.org).The manuscript benefitted from the reviews of Michel Gregoire and an anonymous reviewer, and editorial handling and comments of Sonja Aulbach.