Spodumene from rare-metal pegmatites of the Kolmozero lithium world-class deposit on the Fennoscandian shield: trace elements and crystal-rich fluid inclusions
Lyudmila N. Morozova, E. N. Sokolova, S. Z. Smirnov, Viсtor V. Balagansky, Aya V. Bazai
Abstract
Abstract The paper investigates trace elements and crystal-rich fluid inclusions in spodumene from rare-metal pegmatites of the Kolmozero lithium deposit in the Kola region, Russia. The main lithium mineral in the pegmatites is spodumene, which occurs in three generations, designated as Spd-I, Spd-II and Spd-III. Iron, Na and Mn are the most typical element impurities in spodumene. The Fe/Mn ratio is 7.1 in Spd-I, 12.3 in Spd-II and 13.2 in Spd-III. Spd-II contains fluid and crystal-rich fluid inclusions. The crystal-rich fluid inclusions in Spd-II originally trapped CO 2 -bearing aqueous fluids with dissolved alkali carbonates. The crystal-rich fluid inclusions contain zabuyelite (Li 2 CO 3 ) and cristobalite (SiO 2 ) as solid phases, which have not been reported previously from the Kolmozero rare-metal pegmatites. These minerals are assumed to have resulted from a reaction between a CO 2 -bearing aqueous fluid and host Spd-II and are not related to the mineral-forming system of pegmatites.