Graphite-bearing mineral assemblages in the mantle beneath Central Aldan superterrane of North Asian craton: Combined confocal micro-Raman and electron microprobe characterization / Nikolenko E.I., Sharygin I.S., Alifirova T.A., Korsakov A.V., Zelenovskiy P.S., Shur V.Y. // Journal of Raman Spectroscopy. - 2017. - V. , l. .

ISSN:

03770486

Type:

Article in Press

Abstract:

Mantle-derived lherzolitic and harzburgitic Cr-pyropes from lamprophyres of the Chompolo field (Central Aldan superterrane, North Asian Craton) were studied using micro-Raman spectroscopy and electron microprobe microanalysis. These garnets enclose graphite coexisting with forsterite, diopside, Ba-Cl-phlogopite, tschermakite, rutile, magnesiochromite, Mg-ilmenite, apatite, chalcopyrite, dolomite, magnesite and lindsleyite inclusions. The PT conditions of residence of graphite-bearing assemblage in the mantle were estimated, using a combination of mineral thermometers and barometers, to be as high as 2.87-3.55 GPa and 710-770 °C. Generally, graphite within inclusions is well ordered; D1 and D2 disordered bands in its spectra are restricted to inclusion edges. The residual pressure up to 2.1 GPa was inferred for graphite assuming pressure dependence of the G-band upshift (1580 cm-1 at ambient conditions vs 1588.6 cm-1 at 2.1 GPa). Disordered graphite most likely appears due to the stress-induced distortion of the fully ordered graphite crystal structure. The distortion results from difference in the thermoelastic properties of graphite inclusions and their garnet hosts exposed to decompression during ascent to the surface with lamprophyre magma. The mineralogy of inclusions in the studied garnets strongly suggests an episode(s) of metasomatism by carbon-rich agent(s) (COH-fluid or carbonatitic melt) in the lithospheric mantle of the Central Aldan superterrane, which was coeval with the formation of graphite inclusions and the host pyropes. © 2017 John Wiley & Sons, Ltd.

Author keywords:

Carbonate; Craton; Deep carbon cycle; Graphite; Mantle

Index keywords:

нет данных

DOI:

10.1002/jrs.5163

Смотреть в Scopus:

https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019099964&doi=10.1002%2fjrs.5163&partnerID=40&md5=cac3822428c3abf0eceebaebad11c59e

Соавторы в МНС:

Другие поля

Поле	Значение
Link	https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019099964&doi=10.1002%2fjrs.5163&partnerID=40&md5=cac3822428c3abf0eceebaebad11c59e
Affiliations	Sobolev Institute of Geology and Mineralogy Siberian Branch of Russian Academy of Science Koptyuga ave. 3 Novosibirsk 630090 Russia; School of Natural Sciences and Mathematics Ural Federal University Lenin Ave. 51 Ekaterinburg 620000 Russia
Author Keywords	Carbonate; Craton; Deep carbon cycle; Graphite; Mantle
Correspondence Address	Nikolenko, E.I.email: nevgeny@igm.nsc.ru
Publisher	John Wiley and Sons Ltd
CODEN	JRSPA
Language of Original Document	English
Abbreviated Source Title	J. Raman Spectrosc.
Source	Scopus