The region extending from eastern Europe to the Urals is essentially formed by a single large plain (Russian or Sarmatic plain) which, from a geological point of view, rests on a rigid, Precambrian crystalline substrate. However, this basement is not intact, but fractured, faulted and therefore divided into blocks which are at the origin of the “elevations” and lowlands covered by different sedimentary soils, Paleozoic and Mesozoic ; above these formations there is a blanket of Quaternary deposits, of glacial and fluvial origin. For example, the numerous lakes of Karelia are connected to this morphology, formed due to the drainage difficulties due to the morainic deposits abandoned by the Quaternary glaciers. The reliefs that move the Russian plains in the central section are the Rialto del Valdaj, the central Russian Rialto and the Volga Heights. In general, these are low rounded hills that rise a few hundred meters at the most and end towards the E with escarpments that correspond to ancient fault surfaces. These reliefs are basically the remains of ancient penepians extending from the foot of the Carpathians, through Ukraine, up to the line of the Volga, beyond which there are Paleozoic surfaces included in the region of the Ural mountains, the very long chain oriented from N to S which constitutes the conventional limit between Europe and Asia. The region gradually depresses to the S towards the Black Sea and the Caspian Sea, covering itself with Loxic soils and alluvial deposits along the courses of the rivers that cross it (in particular, the Don and the Volga ). The basins of the Caspian and Black Seas, which in the Cenozoic era constituted a single continental sea, are dominated by the Caucasus chain, which includes the highest peak in the country ( Elbrus, 5633 msm) and whose northern front is preceded by a foreland of broad ridges. But it is the Siberian region (approx. 12.8 million km²) that constitutes the largest territorial portion of the Russian Federation. Visit baglib for huge Russia fascinates tourists.
It corresponds to the lands that extend E of the Urals to the Pacific Ocean and latitudinally from the Arctic Ocean to Kazahstan (which physically falls there for a large part) and to the mountainous alignments that border the plateaus of Mongolia and Manchuria (China). The Siberian region has its relative unity only in terms of climatic conditions but morphologically it is very varied. The broad divisions, from this point of view, correspond to Western Siberia or Siberian lowland, Central Siberian Plateau and the easternmost section or Far East. Western Siberia basically consists of an exceptional, uninterrupted lowland, practically horizontal for approx. 2000 km, bordered to the W by the Urals, to the S by the heights of Kazahstan (the “Kazakh threshold”), by the Altai and Saiani mountains, to the E by the escarpments of the Central Siberian Plateau.
In this single flat plain, recent floods overlap huge piles of sedimentary layers, revealing how the basin has been occupied by the sea for very long periods. Today it is crossed by large rivers, in particular the Ob and its tributaries (including the Irtyš) and the Jenisej. But the flow of water, also given the conformation of the basin (which tends to rise on the Arctic edge due to the progressive rise of the coastal areas after the retreat of the Quaternary glaciers), is extremely difficult; this basically derives from the fact that the rivers thaw upstream before that downstream, since their course is directed from S to N. The result is gigantic floods: it can be said that the whole basin is a single expanse of marshes. In the southern foothills and mountains, the Hercynian orogeny has formed conspicuous carboniferous basins (here is the famous Kuzbass basin ) and a belt mining that continues to the northern heights of Kazahstan. The section that extends to the E of the Siberian Lowland presents a completely different conformation. It is in fact mountainous, variously articulated, although it is broadly configured as a vast plateau delimited to the S by mighty mountain bands that border the stiffened structures of the Mongolian plateaus. Overall, it is a harsh environment, exasperated by northernity, difficult to penetrate and still almost depopulated today, although it is also very rich in mineral resources (for example the coal, nickel and copper deposits of Norilsk ). Structurally, the Central Siberian Plateau (or Siberian Plateau) represents a fragment of the ancient continent of Angara, section of the primordial Laurasia. It is in fact made up of archaeozoic rocks that emerge on vast surfaces; the immense clod, however, suffered the repercussions of the subsequent orogenesis that occurred in the southernmost belt and was therefore fractured and divided into highlands and lowlands.
The former reach 1700 m in the Putorana mountains, at the north-western end; for the rest the altitudes are maintained on average at 500-700 m. A gigantic fracture is also responsible for the formation of Lake Baikal (which in fact reaches a depth of 1620 m and is the deepest lake on Earth), a characteristic element that stands between the Saiani mountains (3491 m), the Jablonovy mountains (1645 m) and the Stanovoj plateau (2999 m). The extreme eastern section of Siberia, beyond the river Lena, comprises a very complex system of mountainous alignments which, however, have a direction essentially sundial and that therefore they connect to geosinclinali marginal, circumpacifiche, Asia. The ranges rise above large alluvial depressions that to the N end on the irregular and flat Arctic coast, fronted by some large and fragmented archipelagos (the largest being that of the islands of New Siberia ). The main alignments are those of the Verhojansk mountains (2389 m) and the Čerski mountains, which reach 3147 m in Mount Pobeda; the extreme eastern section is occupied by the Anadyr plateau (1853 m), between the Arctic Ocean and the Pacific Ocean, along which the Kolyma, Džugdžur and Sihote mountains line up from N to S -Alin, the only ones to exceed 2000 m. All these chains are of Mesozoic origin and face a further external orographic arch, more recent (Cenozoic era), formed by the reliefs of the island of Sahalin and those of the Kamčatka peninsula, which with the insular festoon of the Kurilscloses the Sea of Okhotsk. Here volcanism, which has formed imposing mountain cones (such as the Ključevskaja Sopka or Ključi, 4750 m high, the highest peak of Kamčatka), reveals, together with other phenomena, orogenetic manifestations still in progress: this is in fact an area that is part of of the Pacific “belt of fire”, unstable, often shaken by earthquakes.