Palaeoproterozoic UPb zircon ages from Belorussia: new geodynamic implications for the East European Craton

摘要: Abstract The crust in the northwest of East European Craton has traditionally been regarded as part an Archaean nucleus eastern Europe. Recent correlation with Baltic Shield Scandinavia, however, suggests need reappraisal. To study this problem, zircons from three boreholes basement Russian Platform Belorussia (Belarus) have dated by U-Pb and Pb-Pb methods. ages indicated two discordias are 1982±26 Ma for a metadacite Central Belorussian Belt volcanic-arc igneous rocks, 1800±7 mafic granulite Baltic-Belorussian Granulite largely built up rocks. For another metadacite, age 1975±10 was obtained. In previous “stratigraphies” Belorussia, all rocks considered to be important components Archaean, even Early crust. Analyses abraded crystal cores complex one sample separated core rim do not suggest substantially older materials. Together granitoids charnockites, which had, explained result late magmatism metamorphism, therefore characterizing crust, our data indicate dominance Palaeoproterozoic northwestern that adjoins Tornquist-Line boundary between central northeastern conjunction results Finnish-Estonian similarly allegedly but actual fact Proterozoic southern Estonia, existence large crustal belts extending way Finnish Gulf Poland. This implies substantial revision established concepts on Precambrian geology half continent.