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EEP basement is made up of three main crustal segments Baltia, Sarmatia and Volgouralia, which have been assembled in two stages: early accretion of the Volgouralia and Sarmatia not later 2.0 Ga and subsequent adding to this continental mass the Baltia complexes at 1.7-1.8 Ga. Sarmatia and Volgouralia are in contact during Toropez-Serdobsk accretion-collision belt, Losevo volcanic"Cplutonic belt and Vorontsovka flyschoid complex. This Sarmatia - Volgouralia continental massive were conjugated to the Baltia through the Moscow accretion-collision belt and its possible extension to south - Osnitsk-Mikashevichi belt. The metamorphic events succession was established in the EEP Precambrian segments evolution characterized the crust forming processes inherent to different terrains, its combinations or separated suture zones. Sarmatia: (1) ca 3.2 Ga Mezoarchaean UHT (900-1000 C, 9-11 kb) metamorphism of Oskol-Azov terrain; (2) 2.7-2.8 Ga granulite and amphibolite facies metamorphism of Podolian and Middle Dniepr terrains (Claesson et al. 2006) as well as amphibolite facies (600-650 C, 4-5 kb) metamorphism of Neoarchaean BIF; (3) 2.1 Ga zonal metamorphism (350-650 C, 2-5 kb) of Paleoproterozoic BIFs and amphibolite to granulite facies metamorphism of Bragin terrain; (4) 2.06-2.08 amphibolite facies metamorphism of Volyn and Podolian domains connected with postcollision granites intrusion (Claesson et al. 2006). Baltia: (1) 2.8-2.85 Ga high-grade amphibolite facies moderately HP metamorphism and migmatization within the Central Kola terrain, as well as greenschist to amphibolite facies of the Karelian greenstone area (Slabunov et al., 2006); (2) 2.75-2.65 HP metamorphism (740-865 C, 14.0-17.5 kb) of the Belomorian mobile belt (Bibikova et al. 2003; Volodichev et al. 2004); (3) 1.91-1.95 Ga collision metamorphism (860-960 C, 10.3-14.0 kb) of the Lapland granulite belt (Lapland and Kovitsa-Umba terrain) (Bibikova et al. 1993). (4) 1.79-1.85 Ga zonal LP greenschist to granulite metamorphism of the northern Ladoga region, granulite metamorphism western Lithuanian terrain (850-900 C, 8-10 kb), Belarus-Podlasie mobile belt and Vitebsk terrain (750 C, 8 kb) (Bogdanova et al., 2006). Volgouralia: 2.71-2.72 Ga granulite and amphibolite facies metamorphism (Bibikova, 1995); 1.80-1.90 Ga metamorphism connected with the Volgouralia and Baltia collision. The Volgouralia and Sarmatia collision have been occurred during the Paleoproterozoic island arc development of the eastern part of Sarmatia, that is the cause of their ∼2.1 Ga zonal metamorphism (450-730 C, 3-5 kb). However granulite complexes (900 C, 8-9 kb) of the Moscow belt was formed at 1.9 Ga. Later metamorphic reworking of the southern Baltia terrains was occurred in epidote-amphibolite facies conditions at 1.75 Ga. As evidenced by the foregoing Sarmatia differs from Baltia in the timing of main metamorphic events, suggesting distinguished crust-forming tectonic regimes.
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