Journal article
Did diamond-bearing orangeites originate from MARID-veined peridotites in the lithospheric mantle?
A Giuliani, D Phillips, JD Woodhead, VS Kamenetsky, ML Fiorentini, R Maas, A Soltys, RA Armstrong
Nature Communications | Published : 2015
DOI: 10.1038/ncomms7837
Abstract
Kimberlites and orangeites (previously named Group-II kimberlites) are small-volume igneous rocks occurring in diatremes, sills and dykes. They are the main hosts for diamonds and are of scientific importance because they contain fragments of entrained mantle and crustal rocks, thus providing key information about the subcontinental lithosphere. Orangeites are ultrapotassic, H2O and CO2-rich rocks hosting minerals such as phlogopite, olivine, calcite and apatite. The major, trace element and isotopic compositions of orangeites resemble those of intensely metasomatized mantle of the type represented by MARID (mica-amphibole-rutile-ilmenite-diopside) xenoliths. Here we report new data for two ..
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Funding Acknowledgements
We acknowledge Graham Hutchinson for support with microprobe analyses, Alan Greig for assistance with laser ablation and solution ICP-MS analyses, Karsten Goemann for support with FE-SEM analyses and Matthew Felgate for performing the Nd-Hf isotope analysis. De Beers Consolidated Mines and Simon Shee are thanked for providing access to the studied samples. We acknowledge funding from the Australian Research Council (D.P., V.S.K. and M.L.F.). This is contribution 587 from the ARC Centre of Excellence for Core to Crust Fluid Systems (http://www.ccfs.mq.edu.au).