Tectonic structure of the West Siberian Plain. West Siberian plate

The West Siberian Plain belongs to the accumulative type and is one of the largest lowland plains on the planet. Territorially it belongs to the West Siberian plate. On its territory are the regions of the Russian Federation and the northern part of Kazakhstan. The tectonic structure of the West Siberian Plain is ambiguous and diverse.

Tectonic structures of Russia

Russia is on the territory of Eurasia, the largest continent on the planet, which includes two parts of the world - Europe and Asia. The tectonic structure of the Ural mountains divides the sides of the world. The map gives an opportunity to visually see the geological structure of the country. Tectonic zoning separates the territory of Russia into such geological elements as platforms and folded areas. The geological structure has a direct connection with the topography of the surface. Tectonic structures and forms of relief depend on the area in which they relate.

Within Russia there are several geological regions. Tectonic structures of Russia are represented by platforms, folded belts and mountain systems. On the territory of the country, almost all areas underwent folding processes.

The main platforms within the territory of the country are the East European, Siberian, West Siberian, Pechora and Scythian. They, in turn, are divided into plateaus, lowlands and plains.

Ural-Mongolian, Mediterranean and Pacific are involved in the structure of folded belts. Mountain systems on the territory of Russia - the Greater Caucasus, Altai, Western and Eastern Sayans, Verkhoyansky Range, the Ural Mountains, the Chersky Range, the Sikhote-Alin Range. Can tell about how they were formed, a stratigraphic table.

The tectonic structure, the shape of the relief on the territory of Russia, is very complex and diverse from the point of view of morphology, geomorphology, origin and orography.

Geological structure of Russia

The position of the lithospheric plates that is observed today is the result of a complex long geological development. Within the lithosphere, large areas of land are distinguished, which differ from each other in the different composition of rocks, their occurrence and geological processes. During the geotectonic zoning, attention is paid to the degree of change in the rocks, the composition of the foundation rocks and the sedimentary cover, and the intensity of the foundation movements. The territory of Russia is divided into folded areas and regions of epiphlatform activation. Geotectonic zoning covers all tectonic structures. The stratigraphic table contains data on the modern geotectonics of the territory of Russia.

Forms of relief are formed due to deep movements and external influences. A special role is played by the activity of rivers. In the course of their life, river valleys and ravines are formed. The shape of the relief also forms a glaciation. As a result of the glacier on the plains appear hills and ridges. The shape of the relief is still affected by permafrost. The result of freezing and thawing of groundwater is the process of subsidence.

The Siberian Precambrian platform is an ancient structure. In its central part is the region of the Karelian folding, in the west and south-west the Baikal folding was formed . In the region of the West Siberian and Siberian lowlands, the Hercynian folding became widespread.

Relief of Western Siberia

The territory of Western Siberia is gradually sinking from south to north. The relief of the territory is represented by a great variety of its forms and is complex in origin. One of the important criteria of the relief is the difference in absolute marks. On the West Siberian Plain, the difference in absolute marks is tens of meters.

The flat terrain and insignificant elevations are due to the small amplitude of plate movement. On the periphery of the plain, the maximum amplitude of the uplift reaches 100-150 meters. In the central and northern parts, the amplitude of descent is 100-150 meters. The tectonic structure of the Central Siberian plateau and the West Siberian Plain in the late Cenozoic was relatively calm.

Geographical structure of the West Siberian Plain

Geographically, in the north the plain borders on the Kara Sea, in the south the border runs through the north of Kazakhstan and captures a small part of it, in the west it is controlled by the Ural Mountains, in the east - by the Central Siberian Plateau. From north to south the length of the plain is about 2500 km, the length from west to east varies from 800 to 1900 km. The area of the plain is about 3 million km ² .

The relief of the plain is monotonous, almost level, occasionally the height of the relief reaches 100 meters above sea level. In the western, southern and northern parts of it, the height can reach up to 300 meters. The lowering of the territory occurs from the south to the north. In general, the tectonic structure of the West Siberian Plain is reflected in the terrain.

On the territory of the plain the main rivers - the Yenisei, the Ob, the Irtysh, there are lakes and marshes. The climate is continental.

Geological structure of the West Siberian Plain

The location of the West Siberian Plain is confined to the epicercine slab of the same name. The rocks of the basement are strongly dislocated and belong to the Paleozoic period of time. They are covered with a layer of marine and continental Mesozoic-Cenozoic deposits (sandstones, clays, etc.) with a thickness of more than 1000 meters. In the basins of the basement, this capacity reaches up to 3000-4000 meters. The southern part of the plain shows the youngest - alluvial-lacustrine deposits, in the northern part there are more mature - glacial-marine sediments.

The tectonic structure of the West Siberian Plain includes a foundation and a cover.

The basement of the plate has the appearance of depression with steep sides from the east and northeast and flat from the south and west. The foundation blocks refer to the pre-Paleozoic, Baikal, Caledonian and Hercynian times. The basement is dissected by deep faults of different ages. The largest faults of the submeridional strike are the East Zaural and Omsk-Purian faults. A map of tectonic structures shows that the surface of the base of the slab has an Exterior instrument belt and an Inner area. The entire surface of the basement is complicated by a system of uplifts and depressions.

The cover is interlaced by coastal-continental and marine sediments with a thickness of 3000-4000 meters in the south and 7000-8000 meters in the north.

The Central Siberian Plateau

The Central Siberian plateau is in the north of Eurasia. It is located between the West Siberian Plain in the west, the Central Yakut plain in the east, the North Siberian lowland in the north, the Baikal region, the Transbaikal and the Eastern Sayans in the south.

The tectonic structure of the Central Siberian plateau is confined to the Siberian platform. The composition of its sedimentary rocks corresponds to the period of the Paleozoic and Mesozoic. Typical peoples for it are stratified intrusions, which consist of trapps and basaltic covers.

The relief of the plateau consists of wide plateaus and ridges, at the same time there are valleys with steep slopes. The average height of the drop in the relief is 500-700 meters, but there are parts of the plateau where the absolute elevation rises above 1000 meters, such areas include the Yenisei Ridge and the Angara-Lena Plateau. One of the highest parts of the territory is the Putorana Plateau, its height is 1701 meters above sea level.

The median ridge

The main dividing ridge of Kamchatka is the Median Range. The tectonic structure represents a mountain chain consisting of systems of peaks and passes. The ridge extends from north to south and its length is 1200 km. In its northern part, a large number of passes is concentrated, the central part represents large distances between peaks, in the south a strong dissection of the massif is observed, and the asymmetry of the slopes characterizes the Median Range. The tectonic structure is reflected in the relief. It includes volcanoes, lava plateaus, mountain ranges, glacier-topped peaks.

The ridge is complicated by the structures of the lower order, the brightest of them are Malkinsky, Kozyrevsky, Bystrinsky ridges.

The highest point belongs to the Ichinsky hill and is 3621 meters. Some volcanoes, such as Huvhoytun, Alnay, Shishel, Ostra Sopka, exceed the 2500 meter mark.

The Ural Mountains

The Ural Mountains are a mountain system that lies between the East European and West Siberian Plains. Its length is more than 2000 km, the width varies from 40 to 150 km.

The tectonic structure of the Ural Mountains belongs to the ancient fold system. In the Paleozoic there was a geosyncline and a splashing sea. Beginning with the Paleozoic, the Urals mountain system is being formed. The main formation of folds occurred in the Hercynian period.

Intensive folding occurred on the eastern slope of the Urals, which was accompanied by deep faults and intrusion, the dimensions of which reached about 120 km in length and 60 km in width. The folds here are compressed, overturned, complicated by thrusts.

On the western slope the folding occurred less intensively. The folds here are simple, without thrusts. There are no intrusions.

Pressure from the east created a tectonic structure - the Russian platform, the foundation of which prevented the formation of folding. Gradually the folded mountains appeared on the site of the Ural geosyncline .

Tectonically, the entire Urals is a complex complex of anticlinoria and synclinoria, separated by deep faults.

The relief of the Urals is asymmetric from east to west. The eastern slope slopes steeply towards the West Siberian Plain. The gentle western slope smoothly passes into the East European Plain. Asymmetry caused by its activity the tectonic structure of the West Siberian Plain.

The Baltic Shield

The Baltic Shield belongs to the northwest of the East European Platform, is the largest protrusion of its basement and is elevated above sea level. In the north-west the border passes with the folded structures of Caledonia-Scandinavia. In the south and south-east, the shield rocks are submerged under the cover of sedimentary rocks of the East European plate.

Geographically, the shield is attached to the south-eastern part of the Scandinavian Peninsula, to the Kola Peninsula and Karelia.

Three segments are involved in the structure of the shield, different in age - South Scandinavian (western), Central and Kola-Karelian (eastern). The Southern Scandinavian sector is tied to the south of Sweden and Norway. In its composition the Murmansk block is allocated.

The central sector is located in Finland and Sweden. It includes the Central-Kola block and is located in the central part of the Kola Peninsula.

The Kola-Karelian sector is located on the territory of Russia. It belongs to the most ancient structures of formation. A number of tectonic elements are distinguished in the structure of the Kola-Karelian sector: Murmansk, Central-Kola, White Sea, Karelian, among themselves they are separated by deep faults.

Kola Peninsula

The Kola Peninsula is tectonically tied to the north-eastern part of the Baltic crystalline shield, composed of rocks of ancient origin - granites and gneisses.

The relief of the peninsula took over the features of the crystalline shield and reflects the traces of faults and cracks. The appearance of the peninsula was influenced by glaciers, which smoothed the tops of the mountains.

The peninsula is divided according to the nature of the relief into the western and eastern parts. The relief of the eastern part is not as complex as the western one. The mountains of the Kola Peninsula have the form of pillars - on the tops of the mountains there are flat plateaus with steep slopes, below there are lowlands. The plateaus are cut by deep valleys and gorges. In the western part are the Lovozero tundra and the Khibiny, the tectonic structure of the latter refers to the mountain massifs.

Hibiny

Geographically, the Khibins are referred to the central part of the Kola Peninsula, they represent a large mountain massif. The geological age of the massif exceeds 350 million years. Mountain Khibiny - tectonic structure, which is an intrusive body (solidified magma) is complex in structure and composition. From the geological point of view, the intrusion is not an outflowing volcano. The array continues to rise and now, for a year the change is 1-2 cm. The composition of the intrusive massif contains more than 500 types of minerals.

There are no glaciers in the Khibiny, but traces of ancient ice are found. The tops of the massif are plateau-like, the slopes are steep with lots of snowfields, avalanches are active, many mountain lakes are active. Hibiny relatively low mountains. The very high mark above sea level belongs to the mountain Yudichvumchorr and corresponds to 1200.6 m.