Russian Empire Bolsheviks followed in 1918. The administrative boundaries of European Russia, apart from Finland and its portion of Poland, coincided approximately with the natural limits of the East-European plains. In the North it met the Arctic Ocean. Novaya Zemlya and the Kolguyev and Vaygach Islands also belonged to it, but the Kara Sea was referred to Siberia. To the East it had the Asiatic territories of the Empire, Siberia and the Kyrgyz steppes, from both of which it was separated by the Ural Mountains, the Ural River and the Caspian Sea — the administrative boundary, however, partly extending into Asia on
Geology of Russia North Kara Terrane. It consists of a Neoproterozoic basement, consisting of metamorphosed sedimentary rocks intruded by granites, which is covered by Upper Neoproterozoic and Paleozoic sedimentary rocks. The North Kara Terrane collided with Siberia around the Devonian-Carboniferous boundary. This collision, which is related to the Caledonian orogeny, is called the Severnaya Zemlya episode. Geology of Russia The geology of Russia, the world's largest country, which extends over much of northern Eurasia, consists of several stable cratons and sedimentary platforms bounded by orogenic (mountain) belts. The European part of Russia is on the East European craton, at the heart of which