Journal article

The final stages of kimberlite petrogenesis: Petrography, mineral chemistry, melt inclusions and Sr-C-O isotope geochemistry of the Bultfontein kimberlite (Kimberley, South Africa)

Andrea Giuliani, Ashton Soltys, David Phillips, Vadim S Kamenetsky, Roland Maas, Karsten Goemann, Jon D Woodhead, Russell N Drysdale, William L Griffin

CHEMICAL GEOLOGY | ELSEVIER SCIENCE BV | Published : 2017

Abstract

The petrogenesis of kimberlites is commonly obscured by interaction with hydrothermal fluids, including deuteric (late-magmatic) and/or groundwater components. To provide new constraints on the modification of kimberlite rocks during fluid interaction and the fractionation of kimberlite magmas during crystallisation, we have undertaken a detailed petrographic and geochemical study of a hypabyssal sample (BK) from the Bultfontein kimberlite (Kimberley, South Africa). Sample BK consists of abundant macrocrysts (> 1 mm) and (micro-) phenocrysts of olivine and lesser phlogopite, smaller grains of apatite, serpentinised monticellite, spinel, perovskite, phlogopite and ilmenite in a matrix of calc..

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Grants

Awarded by Australian Research Council through a DECRA award


Funding Acknowledgements

We would like to thank Graham Hutchinson and Alan Greig for support with the EMP and LA-ICPMS analyses at the University of Melbourne, and Simon Shee and Jock Robey for insightful discussions on the geology and petrology of the Kimberley kimberlites. We are also grateful to the De Beers Group for providing access to sample BK. This work benefitted from very constructive and thorough reviews by Hugh O'Brien, Troels Nielsen and an anonymous referee, and the careful editorial handling of Sebastian Tappe.AG acknowledges funding from the Australian Research Council through a DECRA award (DE-150100009) and from the Australian Academy of Sciences through a J. G. Russell Award. This is contribution 856 from the ARC Centre of Excellence for Core to Crust Fluid Systems (http://www.ccfs.mq.edu.au) and 1114 in the GEMOC Key Centre (http://www.gemoc.mq.edu.au).