Olivine-chrome-spinel equilibrium in chromitites and ultramafites of Rai-Iz massif, Polar Urals
Abstract
Olivine and chrome-spinel compositions from chromitites and ore-bearing metamorphosed ultramafic rocks of Rai-Iz massif were compared. It was established that olivine and spinel ferruginosity are directly proportional and increase monotonically from chromitites to ultramafic rocks that indicates the existence of equilibrium in the ore-rock system. The compositions of accessory spinel are in agreement with compositions of ferrichromite and chromemagnetite, which are highly oxidized spinel group minerals, typical for metamorphic ultramafic rocks. The obtained results suggests that chromitites and metamorphosed ultramafic rocks are products of a single process which is metamorphic differentiation of ultramafic rocks.
About the Authors
P. B. Shirjaev
Institute of Geology and Geochemitry Urals Branch of RAS
Russian Federation
Russian Federation
N. V. Vakhrusheva
Institute of Geology and Geochemitry Urals Branch of RAS
Russian Federation
Russian Federation
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Review
For citations:
Shirjaev P.B., Vakhrusheva N.V. Olivine-chrome-spinel equilibrium in chromitites and ultramafites of Rai-Iz massif, Polar Urals. LITHOSPHERE (Russia). 2016;(2):107-110. (In Russ.)
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