Н.М. Кудряшов, Е.В. Галеева, О.В. Удоратина, А.А. Калинин, М. Гроув.
Архейская эпоха редкометалльного (Li, Cs) пегматитообразования в северо-восточной части Фенноскандинавского щита
Keywords: rare metal (Li, Cs) pegmatite; U-Pb isotope age; SHRIMP-RG; zircon; Okhmyl’k and Vasin-Myl’k deposits; Fennoscandian Shield
The results of isotope geochronological study of zircons from rare metal pegmatite deposits Okhmyl’k and Vasin-Myl’k are presented. Up to date no reliable data on the age of pollucite-spodumene-lepidolite pegmatite veins in the Archean greenstone belt Kolmozero-Voron’ya were available, the age estimations varied within a long time interval from 2.7 to 1.7 Ga. New U-Pb (SHRIMP-RG) data for zircons indicate crystallization of pegmatite at 2607±9 Ma in the Okhmyl’k and 2619±29 in the Vasin-Myl’k. This age corresponds to the global Archean stage of rare metal pegmatite formation at 2.65 – 2.60 Ga. Isotope data for ~1.7 – 1.6 Ga indicate the age of the late hydrothermal-metasomatic processes in pegmatite veins.
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