Russian Platform

Russian Platform: see Baltic Shield.

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Russian Platform 

a portion of the Eastern European Platform, located between the Baltic and Ukrainian shields, the Urals, and the Timan Ridge. It is covered by a thick mantle of sedimentary deposits. The Precambrian basement of the Eastern European Platform within the limits of the Russian Platform is located at a great depth, particularly in the southwest and southeast, where the depth may reach 16–18 km.

Beginning with the Riphean, the Russian Platform experienced deformations that gradually complicated its structure. The leading process in these deformations was a progressive downwarping that occurred at different times in various areas. The main structural elements of the Russian Platform are tectonic depressions (syneclises), arches (anteclises), and aulakogenes. The formation of the complex of deposits in the sedimentary mantle occurred from the beginning of the Late Proterozoic through the Quaternary. At the end of the Riphean, a significant portion of the Eastern European Platform south of the Baltic Shield sank and was covered by a sea until the end of the Silurian. Beginning with the Middle Devonian, the more southern portion of the Russian Platform sank and was also covered by a sea. The Baltic, Moscow, and Caspian tectonic depressions began forming, bounded by the Masurian-Byelorussian and Voronezh arches and divided by the Volga-Urals arch. The tectonic depressions are filled with series of Devonian, Carboniferous, and Permian deposits and, in the southern part, with Mesozoic and Cenozoic deposits. At the end of the Proterozoic, the Dnieper-Donets aulakogene was formed south of the Byelorussian and Voronezh arches; it is filled with Triassic, Jurassic, Cretaceous, and Paleogenic deposits. Within the Donets Basin, at the end of the Paleozoic, the strata were crushed into a complex system of folds. Among the Quaternary formations in the north of the Russian Platform, morainic deposits are particularly characteristic, and in the south, sands and loess-like loams are typical.