The enormous territory of the Russia can be decomposed, simplifying a lot, into a few large morphological units. From the structural point of view, we can speak of two stable blocks, that of Eastern Europe (continuation of the Baltic shield) and that of Siberia, separated and surrounded by reliefs dating back to the various orogenetic cycles and further modified. In the whole of the Russia, about two thirds of the surface is flat and below 300 m in height.
Russian lowland
From West to East and from North to South, we first encounter the great Russian lowland, which extends as far as the Ural mountains and, beyond, the Siberian lowland (Western Siberia). This reaches E up to the course of the Enisej river, beyond which the Siberian Plateau rises a few hundred meters, which reaches beyond Lake Baikal and the Lena river, finally giving way to a more tormented mountainous region (Extreme East Russian). AS extend the southern parts of the great flat units of the north, which descend to the water collection basins (Black Sea, Caspian Sea, Aral Sea), and a series of mountain ranges: Caucasus, between the Black Sea and the Caspian, Altaj and Saiani, to the South of western and central Siberia, Iablonovyi and Stanovoj, to the East of Lake Baikal, and the reliefs near the Pacific.
● The Russian lowland is made up of a base of archaic rocks covered by more recent and intensely remodeled formations during the Quaternary glaciations. The highest altitudes, above 1200 m, are reached near the Norwegian border, in the Kola Peninsula. Further south are the lakes of glacial excavation, including Ladoga and Onega, the largest in Europe. Still to the South, the Palaeozoic rocks and the moraines of the Valdaj emerge, which, although slightly over 300 m in height, are an important continental watershed, from which the Western Dvina flows to the West towards the Baltic, to the South the Dnieper towards the Black Sea and E the Volga towards the Caspian Sea. The last two basins are divided by series of hills: the Rialto Centrale Russo, which does not reach 300 m in height, and the Volga Heights (390 m). AS of the Rialto Centrale are the Donec hills, whose waters have deeply affected the reliefs, highlighting enormous coal deposits. Here the Russian Lowland has a slight inclination towards the West, making the valleys of the rivers asymmetrical, whose western bank is often steep and even more than 100 m high, while wide plains extend on the eastern bank.
● Between Valdaj, the Central Rialto and the Volga Heights, is the Sarmatic Plain, bordered to the North by a series of low moraine reliefs, between Lake Onega and the Urals, beyond which the plain extends towards the Arctic Ocean, over 500 km wide, crossed by the Northern Dvina and the Pečora, whose basins are separated by the Timani Mountains. The whole region is subject, as in northern Siberia, to a very slow uplift, which further attenuates the already very low slope of the rivers. The southern limit of the European part is marked, between the Black Sea and the Caspian Sea, by the Caucasus, where, on the El′brus, it exceeds 5600 m in height.
Ural Mountains
The Ural Mountains stretch in the meridian direction for over 2000 km, and consist of a main chain that reaches 1894 m to the North (Narodnaja Gora), but generally does not exceed 1200; towards noon parallel, higher formations join it. The Urals are rich in both metal and energy resources, to the point that the central sector of the chain is called the Ore Urals (the Northern Urals are called Deserts, the southern ones Wild). In the Arctic Ocean, the relief of the Urals extends to the islands of Novaya Zemlya.
Siberia
To the east of the Urals, the large quadrangular Siberian lowland extends for over 1600 km up to the Enisej and for 1900 km from the Arctic Sea on the border with Kazakhstan, always at altitudes below 180 m. The large region is drained by the Ob´, which originates from the Altai and flows into the Gulf of the Ob´. Like all tributaries of the Ocean, the river freezes every year; the spring-summer thaw begins in the S, when the lower course (in the N) is still frozen, which causes enormous flooding. On the mouths of the rivers that flow into the Arctic Sea, the frost lasts over 6 months in Europe, and up to 10 months in Siberia: the northern parts of the plains, therefore, turn into enormous marshes in the summer months. This area is called merzlota in Russian(permafrost): the subsoil is impregnated with frozen waters since the Ice Age (up to 350 m depth, in the Tajmyr peninsula), and therefore is impermeable; the merzlota extends for about 4 million km 2 continuously and for another 6 million discontinuously (a third of which in the European Russia): it follows that a very large part of the surface of the Russia is almost unusable.
● The Siberian Plateau, a series of platforms at heights varying between 300 and 750 m in height, has a width similar to that of the Low plateau and culminates in the N with the Putorana Mountains (1701 m), while it is bordered to the West, a S and E by Hercynian corrugation formations which to the South, with the Saiani and the Altaj, respectively exceed 3400 and 4500 m. The raising of the Iablonovyi and Stanovoj mountains and the formation of the Baikal rift valley, which at over 1600 m is the deepest on Earth (its bottom is 1300 m below sea level), date back to Cenozoic corrugations. All the waters of the Siberian Plateau are collected to the West in the Enisej (via the Angara, Tunguska Pietrosa and the Lower Tunguska) and to the East in the Lena.
● Further east there are chains directed towards the N and NE, such as the mountains of Verhojansk, Čerskij, Kolyma, between which flow, always towards the Arctic Ocean, the rivers Jana, Indigirka and Kolyma. Towards the Bering Strait the tertiary reliefs of Anadyr´ rise, while towards the S the volcanic and seismic peninsula of Camciatca stretches, which closes the Sea of Okhotsk to the E. AS of the Iablonovyi and Stanovoj mountains (Russian Far East), it is part of the Amur river basin and, between its Ussuri tributary and the Pacific, rise the Sichote-Alin´ mountains.
Islands
The coast is fronted by the narrow and long island of Sahalin. The other main islands of the Russia are located in the Ice Sea: further N of Novaya Zemlya are the Franz Josef Land, the Northern Land (Severnaja Zemlya), the New Siberia Islands and the Wrangel Island.
