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Vol. 12 (2009 year), No. 3
Correspondence of Early Proterozoic (Karelian) aeonothem of the General Stratigraphic Scale of Russia to requirements of the standard of basic taxonomic subdivision of the International Stratigraphic Scale has been substantiated. It has been established that geological processes taken place in the Karelian-Kola stratotype of the Lower Proterozoic (Karelian) aeonotem have outlined the whole megacycle of correlated development of all external and internal geospheres in the period between Late Archaean and Early Proterozoic cratonization of the Earth's crust. Standard regional stratigraphic subdivisions of the Karelian aeonothem have shown right periodicity of precipitations storage and denudation, magmatism, structural and tectonic deformations. The perspectives of Karelia and the Kola Peninsula for creation of interregional system of stratotypes have been considered.
(in Russian, стр.8, fig. 4, tables. 1, ref 33, Adobe PDF, Adobe PDF 0 Kb)
Vol. 15 (2012 year), No. 2
Kaulina T.V.
Thermochronology of eclogitic rocks of the Kola Peninsula
According to the results of U-Pb, Sm-Nd and Rb-Sr dating of metamorphic minerals the chronology of metamorphic events and thermal history of eclogitic rocks of the Wide and Narrow Salma and eclogites of the Chalmozero area (Yona district of the Belomorian Mobile Belt, the Kola Peninsula) have been reconstructed. The conclusion has been made that the studied rocks for more than 700 Ma have been located at depth at high temperature, which lead to a disturbance of U-Pb and Sm-Nd system in minerals at temperature below the closure temperatures, obtained experimentally. Closure temperatures for U-Pb and Sm-Nd isotopic systems in rutile are largely dependent on the grain size and cooling rate of rocks. Closure temperature for U-Pb system in 0.3 mm rutile grains can be 600 C, higher than usually accepted 400-450 В°C. Closure temperature for Sm-Nd system in rutile is about 350 C, significantly lower than that for U-Pb system. Duration of metamorphic processes and cooling rate of rocks provide constrains on geodynamic models.
(in English, стр.7, fig. 4, tables. 0, ref 33, Adobe PDF, Adobe PDF 0 Kb)