New Data on Stable Isotopes in Minerals from Corundum-Bearing Formations of Northern Karelia (Russia)

摘要

Far East Geological Institute, Far East Branch, Russian Academy of Sciences, Vladivostok, Russia;Far East Geological Institute, Far East Branch, Russian Academy of Sciences, Vladivostok, Russia;Far East Geological Institute, Far East Branch, Russian Academy of Sciences, Vladivostok, Russia;Far East Geological Institute, Far East Branch, Russian Academy of Sciences, Vladivostok, Russia;Far East Geological Institute, Far East Branch, Russian Academy of Sciences, Vladivostok, Russia;%Rocks and minerals of the Earth are usually enriched in ~(18)O isotope in comparison with its concentration in modern seawater; i.e., they have positive δ~(18)O values. Most silicate rocks are characterized by δ~(18)O values from +4 to +15%o. Until recently, noble corundum and associating minerals did not often fall outside the limits of this range [1,2]. The appearance of data on corundum of Northern Karelia strongly depleted in heavy oxygen isotope in comparison with SMOW [3—5] caused significant interest, since this suggests quite specific conditions of their formation.