Graphite-diamond relations in mantle rocks: Evidence from an eclogitic xenolith from the Udachnaya kimberlite (Siberian Craton) / Mikhailenko Denis S.,Korsakov Andrey V.,Zelenovskiy Pavel S.,Golovin Alexander V. // AMERICAN MINERALOGIST. - 2016. - V. 101, l. 9-10. - P. 2155-2167.

ISSN/EISSN:
0003-004X / 1945-3027
Type:
Article
Abstract:
Relations of graphite and diamond have been studied in a garnet-kyanite-clinopyroxene+sulfide+coesite/quartz+diamond+graphite eclogite xenolith from the Udachnaya-East kimberlite pipe in the Yakutian diamond province. Euhedral crystals of diamond and graphite occur in the intra- and intergranular space. The equilibrium conditions of diamond formation reconstructed by geothermobarometry for the Grt-Cpx-Ky-Coe mineral assemblage are 1020 +/- 40 degrees C and 4.7 GPa. Raman imaging of graphite enclosed in diamond shows high ordering and a 9 cm(-1) shift of the similar to 1580 cm(-1) band. This Raman shift of graphite, as well as a 5 cm-' shift of the 1332 cm-' band of diamond, indicate large residual stress in graphite and in diamond around the inclusion, respectively. According to FTIR spectroscopy, nitrogen in diamond is highly aggregated and exists mainly as the A centers, while no other phases occur near graphite inclusions. Therefore, diamond in the analyzed eclogite sample must be quite old: it likely had crystallized long (similar to 1 Byr) before it became entrained with kimberlite melt. New data show that graphite can stay in the upper mantle for billions of years without converting to diamond. Crystallization of various carbon polymorphs, both in laboratory and natural systems, remains poorly constrained. Graphite present in mantle and UHP rocks may be a metastable phase crystallized in the diamond stability field. This fact should be taken into consideration when deducing petrological constrains and distinguishing diamond and graphite subfacies in upper mantle.
Author keywords:
Diamond; graphite; metastable graphite; pseudomorphs; UHPM HIGH-TEMPERATURE CONDITIONS; O-H FLUIDS; HIGH-PRESSURE; MINERAL INCLUSIONS; RAMAN-SPECTROSCOPY; YAKUTIAN KIMBERLITES; BEARING ECLOGITE; SOUTH-AFRICA; CARBON; PIPE
DOI:
10.2138/am-2016-5657
Web of Science ID:
ISI:000385605100021
Соавторы в МНС:
Другие поля
Поле Значение
Month SEP-OCT
Publisher MINERALOGICAL SOC AMER
Address 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA
Language English
EISSN 1945-3027
Keywords-Plus HIGH-TEMPERATURE CONDITIONS; O-H FLUIDS; HIGH-PRESSURE; MINERAL INCLUSIONS; RAMAN-SPECTROSCOPY; YAKUTIAN KIMBERLITES; BEARING ECLOGITE; SOUTH-AFRICA; CARBON; PIPE
Research-Areas Geochemistry \& Geophysics; Mineralogy
Web-of-Science-Categories Geochemistry \& Geophysics; Mineralogy
Author-Email pazilovdenis@igm.nsc.ru
ResearcherID-Numbers Zelenovskiy, Pavel/L-7480-2016 Golovin, Alexander/A-7090-2014 Denis, Mikhaylenko/A-8375-2014 Korsakov, Andrey/O-2390-2013
ORCID-Numbers Zelenovskiy, Pavel/0000-0003-3895-4785 Denis, Mikhaylenko/0000-0003-0585-3021 Korsakov, Andrey/0000-0002-4922-7658
Funding-Acknowledgement Russian Science Foundation {[}15-17-30012]; Ministry of Education and Science of the Russian Federation {[}RFMEFI59414X0011]
Funding-Text We greatly appreciate the assistance of our colleagues from IGM (Novosibirsk): E.N. Nigmatulina for EMPA, I.N. Kupriyanov for FTIR spectroscopy of diamonds, A.L. Ragozin for preparing samples for analyses, and E.N. Fedorova for interpretation FTIR data. Thanks are extended to A. Shatskiy for interpretations of data during the manuscript preparation. The paper profited much from constructive criticism by G. Yaxley and an anonymous reviewer. The study was supported by grant RSF No. 15-17-30012 from the Russian Science Foundation and was carried out using the equipment of the Ural Center of Shared Use ``Modern Nanotechnologies{''} supported by the Ministry of Education and Science of the Russian Federation (unique identifier RFMEFI59414X0011).
Number-of-Cited-References 119
Usage-Count-Last-180-days 1
Usage-Count-Since-2013 6
Journal-ISO Am. Miner.
Doc-Delivery-Number DZ1NM