Forbidden mineral assemblage coesite-disordered graphite in diamond-bearing kyanite gneisses (Kokchetav Massif) / Shchepetova O.V., Korsakov A., Mikhailenko D., Zelenovskiy P., Shur V., Ohfuji H. // Journal of Raman Spectroscopy. - 2017. - V. , l. .

ISSN:

03770486

Type:

Article in Press

Abstract:

Confocal 2D and 3D Raman imaging was applied to SiO2 inclusions in kyanite porphyroblasts from diamond-bearing kyanite gneisses of the Kokchetav Massif (Northern Kazakhstan). The study reveals a mineral assemblage of coesite-disordered graphite which is forbidden in ultrahigh pressure-high temperature (UHP-HT) metamorphic complexes. Disordered graphite in coesite inclusions is optically undetectable and has been identified exclusively by Raman spectroscopy. Raman imaging of the forbidden coesite-disordered graphite assemblage fails to detect bands assigned to fluid components (e.g. CO2, N2, CH4, H2Oliq), but the Raman spectra of fluid inclusions in kyanite, garnet and quartz demonstrate the presence of CO2, N2, CH4, H2Oliq and disordered graphite. The disordered graphite most likely formed by precipitation from a C-O-H fluid during the retrograde stage. The fluid was entrapped by kyanite with coesite inclusions near the peak metamorphic conditions. The lack of disordered graphite around diamond crystals in our samples does not support the generally accepted origin of disordered graphite in ultra high pressure metamorphic rocks by partial diamond graphitization during exhumation. © 2017 John Wiley & Sons, Ltd.

Author keywords:

Coesite; Diamond; Disordered graphite; Raman imaging; UHP-HT metamorphism

Index keywords:

нет данных

DOI:

10.1002/jrs.5167

Смотреть в Scopus:

https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019993776&doi=10.1002%2fjrs.5167&partnerID=40&md5=945d033334c6569eb4998805490b474b

Соавторы в МНС:

Другие поля

Поле	Значение
Link	https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019993776&doi=10.1002%2fjrs.5167&partnerID=40&md5=945d033334c6569eb4998805490b474b
Affiliations	Sobolev Institute of Geology and Mineralogy Siberian Branch Russian Academy of Science 3 Ac. Koptyuga ave. Novosibirsk 630090 Russian Federation; Novosibirsk State University Pirogova st. 2 Novosibirsk 630090 Russian Federation; School of Natural Sciences and Mathematics Ural Federal University Ekaterinburg Russian Federation; Geodynamics Research Center (GRC) Ehime University Matsuyama Japan
Author Keywords	Coesite; Diamond; Disordered graphite; Raman imaging; UHP-HT metamorphism
Correspondence Address	Shchepetova, O.V.email: olgashchepetova@igm.nsc.ru
Publisher	John Wiley and Sons Ltd
CODEN	JRSPA
Language of Original Document	English
Abbreviated Source Title	J. Raman Spectrosc.
Source	Scopus