SOLID SOLUTIONS OF KARELIANITE AND ESKOLAITE (Slyudyanka complex, southern Baikal area): GENESIS AND A POSSIBLE PETROGENETIC INDICATOR
L.Z. Reznitsky1, E.V. Sklyarov1, L.F. Suvorova2, I.G. Barash1
1Institute of the Earth’s Crust, Siberian Branch of the Russian Academy of Sciences, ul. Lermontova 128, Irkutsk, 664033, Russia
2A.P. Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Sciences, ul. Favorskogo 1a, Irkutsk, 664033, Russia
Keywords: Eskolaite, karelianite, solid solution, genesis, synthesis
Abstract
A continuous solid-solution series between the end-members eskolaite (98 wt.% Cr2O3) and karelianite (93 wt.% V2O3) has been revealed in Cr-V-bearing rocks of the Sludyanka metamorphic complex. Chromium and vanadium oxides crystallized as karelianite-eskolaite minerals during regional high-temperature prograde (granulite facies) metamorphism and participated in the formation of other Cr-V and Cr-V-bearing phases. Ferrian karelianite (up to 12 wt.% Fe2O3) and three-component solid solutions Esk12-50Kar45-60Hem6-30 occur in metamorphic rocks that have particular protolith compositions (Fe-Kar) and in later metasomatic rocks ((Cr, V, Fe)2O3). Natural eskolaite and karelianite are discussed in terms of paragenesis, and their crystallization conditions are compared with the conditions of their laboratory synthesis.
DOI: 10.15372/RGG2019114
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