Journal article
Noble gas geochemistry of fluid inclusions in South African diamonds: implications for the origin of diamond-forming fluids
S Timmerman, M Honda, D Phillips, AL Jaques, JW Harris
Mineralogy and Petrology | SPRINGER WIEN | Published : 2018
Abstract
Fibrous diamond growth zones often contain abundant high-density fluid (HDF) inclusions and these provide the most direct information on diamond-forming fluids. Noble gases are incompatible elements and particularly useful in evaluating large-scale mantle processes. This study further constrains the evolution and origin of the HDFs by combining noble gas systematics with δ13C, N concentrations, and fluid inclusion compositions for 21 individual growth zones in 13 diamonds from the Finsch (n = 3), DeBeers Pool (n = 7), and Koffiefontein (n = 3) mines on the Kaapvaal Craton. C isotope compositions range from −2.8 to −8.6‰ and N contents vary between 268 and 867 at.ppm, except for one diamond w..
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Awarded by Australian Research Council
Funding Acknowledgements
We thank Peter Holden (SHRIMP) and Xiaodong Zhang (VG5400) for their assistance with the analytical work. The authors acknowledge the facilities, and the scientific and technical assistance, of the Australian Microscopy and Microanalysis Research Facility at the Centre of Advanced Microscopy, The Australian National University. The Diamond Trading Company (a member of the DeBeers Group of Companies) is thanked for the donation of the diamonds used in this study to JWH. We thank Ray Burgess, Yaakov Weiss and editor Oded Navon for their helpful comments that greatly improved the presentation of this paper. This work was funded by the Australian Research Council (DP140101976) to MH, ALJ, DP, and Deborah Araujo, and AGRTP and Ringwood scholarships to ST.