Chlorine from the mantle: Magmatic halides in the Udachnaya-East kimberlite, Siberia

Ultrafresh salty kimberlite of the Udachnaya–East pipe (Yakutia, Russia): A petrological oddity or fortuitous discovery?

“…10), encouraging suspicion that high chloride and sulphate levels may originate through contamination of the kimberlite melt by sedimentary evaporites. Although we have shown that radiogenic isotope (Sr, Nd, Pb) compositions of the water-soluble, labile minerals in the groundmass of least altered Udachnaya-East kimberlites are consistent with a mantle origin and free of obvious sedimentary contributions (Kamenetsky et al, 2009c;Maas et al, 2005), the high δ 18 O values of the carbonate fraction require additional comment.…”

“…Another unusual componentalkali carbonate -is pervasive in the studied samples and represented by Na-and K-bearing minerals (nyerereite, shortite, zemkorite; Egorov et al, 1988;Kamenetsky et al, 2007aKamenetsky et al, , 2007b. The unusual alkali carbonate minerals are closely associated with chlorides, sodalite, K-bearing sulphides and common calcite, olivine, phlogopite, monticellite, perovskite, Cr-spinel and Ti-magnetite (Kamenetsky et al, 2009c;Fig carbonates (pirssonite, trona, hydrocalcite) and perfectly shaped crystals of halite and sylvite (Fig. 4).…”

“…Kimberlites from Udachnaya-East have provided detailed constraints on mineral assemblages and melt composition that are difficult (or impossible) to obtain in more altered kimberlite Kamenetsky et al, 2004Kamenetsky et al, , 2006Kamenetsky et al, , 2007aKamenetsky et al, , 2007bKamenetsky et al, , 2008Kamenetsky et al, , 2009aKamenetsky et al, , 2009bKamenetsky et al, , 2009cMaas et al, 2005;Mernagh et al, 2011;Sharygin et al, 2007Sharygin et al, , 2008. These findings and constraints include: 1) recognition of two populations of olivine, with distinct morphological and chemical features; 2) detailed characterisation of chemical, zoning and growth/resorption features in one of these (the euhedral) olivine population; 3) analysis of the mineral assemblage coexisting with liquidus (euhedral) olivine, based on crystal inclusions in olivine; 4) characterisation of melt and fluid inclusions in olivine; thermometric experiments on these inclusions, directed at understanding temperature and pressure of crystallisation; 5) microanalytical analysis of melt and fluid inclusions (laser Raman spectroscopy, laser ablation ICPMS, proton-induced X-ray emission, electron microprobe, etc.)…”

Experimental and Theoretical Evidence for Surface-Induced Carbon and Nitrogen Fractionation during Diamond Crystallization at High Temperatures and High Pressures

“…The composition of the system was chosen to provide diamond crystallization near the Carbon-Carbon oxide (CCO) buffer from a single carbon source rather than modelling some specific geological situation. However, sodium carbonates were found in fresh kimberlites [37,38] and even as inclusions in diamonds [38,39] and in olivine recovered from kimberlites [40].…”

Chemical abrasion of zircon and ilmenite megacrysts in the Monastery kimberlite: Implications for the composition of kimberlite melts

“…Compositionally-similar melt inclusions, containing carbonates (magnesite, dolomite, Ca-Na-K carbonates), phosphates (apatite and bradleyite), kalsilite, phlogopite, alkali-sulfates and alkalichlorides in ilmenite and olivine of the polymict breccia xenoliths from the Bultfontein kimberlite, have been suggested to be pristine examples of primary kimberlite melt with alkali-carbonate composition entrapped at mantle depths (Giuliani et al, 2012(Giuliani et al, , 2013(Giuliani et al, , 2014. This component is undoubtedly carried from the mantle to the surface by kimberlite magmas, as evidenced by the Na-rich carbonate-chloride melt inclusions trapped in olivine, phlogopite and Cr-spinel phenocrysts in archetypal kimberlites from Siberia, Canada and Greenland (Kamenetsky et al, 2004(Kamenetsky et al, , 2009a(Kamenetsky et al, , 2009b(Kamenetsky et al, , 2013a. We therefore conclude that the melt inclusions trapped in the healed fractures traversing the Monastery megacrysts represent relics of the alkalicarbonate kimberlite melt.…”