Assessment of the relief of Eastern Siberia. North-East of Siberia. Relief, geological structure of North-Eastern Siberia. Gold and diamonds of Eastern Siberia

EASTERN SIBERIA, a natural region located mainly in Russia. It is located in Siberia, between the valley of the Yenisei River and the watershed ranges along the Pacific coast, stretching south of the Chukotka Peninsula. In the north it is washed by the Kara, Laptev and East Siberian seas.

Naturally complex Eastern Siberia includes the following physical and geographical countries: Central Siberia, partly the Altai-Sayan country (with the Eastern Sayan mountain system), North-Eastern Siberia, the Baikal region and Transbaikalia. The relief is dominated by low and middle mountains. In the west, the Central Siberian Plateau, the largest in Russia, stands out. In the east, complex mountain systems (the Verkhoyansky and Chersky ridges, etc.) are combined with plateaus (Yanskoye, Elginskoye, Alazeyskoye, Yukagirskoye, etc.) and uplands (Oymyakonskoye, Kolymskoye, etc.). In the south there are also a number of vast uplands (Stanovoe, Aldan, Patom, etc.). In some high-mountain ranges, alpine landforms with modern glaciation are developed (Orulgan, Momsky, Sunta-Khayata, etc.). In the north, a number of large lowlands stretch - the North Siberian, Yano-Indigirskaya, Kolyma, etc.

The tectonic structures of Eastern Siberia are represented by the Siberian platform and its folded framing: in the north - the Early Mesozoic structure of Taimyr; in the west - the system of the Yenisei Ridge of the Baikal age; in the southeast - the structures of the Salair-Caledonian-Hercynian Altai-Sayan folded region. In the south is the Baikal-Mongol-Okhotsk region, in which the time of the main folding in various mountain systems varies from the late Proterozoic to the late Mesozoic. To the east of the Siberian Platform is the late Mesozoic Verkhoyansk-Chukotka folded region. Mountain building covered the southern part of Eastern Siberia in the Cenozoic. The eastern regions are experiencing active uplift. One of the largest continental rift systems in the world, the Baikal rift system, is located in the south of Eastern Siberia. High seismicity is characteristic of the southern (Lake Baikal basin with adjacent territories, Eastern Sayan) and eastern (Verkhoyansky and Chersky ridges) regions. Strong destructive earthquakes occurred in 1862 (in the delta of the Selenga River), 1927 (Bulun in the Verkhoyansk Range), 1950 (in the Eastern Sayan), 1957 (Muiskoye in Transbaikalia), 1959 (Middle Baikal), 1971 (Artykskoye in the Chersky Range). Known deposits of oil and natural combustible gas, coal, iron ores, gold, uranium, platinum, tin, copper, nickel, cobalt, antimony, mercury, niobium, rare earth elements, as well as diamonds, phlogopite, muscovite, asbestos, stone and potash salt, etc.

The climate of Eastern Siberia is sharply continental. In the regions of Oymyakon and Verkhoyansk, there is the cold pole of Eurasia (absolute minimum -68 °C). Permafrost is ubiquitous, reaching a maximum thickness of 1500 m (the Markha River basin). Thermokarst lakes are numerous in the north and northeast. The largest rivers of Russia flow through the territory of Eastern Siberia: Lena, Yenisei, Kolyma, Indigirka; there is a unique Lake Baikal. The northern lowlands of Eastern Siberia are occupied by tundra: arctic, moss-lichen and shrubs on peat-cryozems. To the south, a narrow strip of forest-tundra without a sharp transition gives way to the northern subzone of taiga larch forests on coarsely humus cryozems. Larch forests are widespread in the middle and southern subzones of the taiga on cryoturbated pale soils and coarsely humus light soils. In the south of the Central Siberian Plateau there are forest-steppe islands. The zonal distribution of the soil and vegetation cover is disturbed in the Byrranga mountains and on the Putorana Plateau, as well as in high areas of the plateaus. The structure of altitudinal zonality in the northeastern part of Eastern Siberia differs sharply from the southern part, where it is more diverse.

Active development of natural resources, the development of large industrial centers has led to the emergence of areas with a tense ecological situation (Norilsk, Kemerovo, Irkutsk, etc.), which is aggravated by the poor ability of the natural environment of this region to self-purify. A number of nature reserves (Taimyrsky, Barguzinsky, Central Siberian, Vitimsky, etc.) and national parks (Pribaikalsky, Zabaikalsky, Tunkinsky, etc.) have been created. The World Heritage List includes: Lake Baikal, the Ubsunur Hollow (most of it is in Mongolia).

Lit .: Plains and mountains of Siberia. M., 1975; Antipova A.V. Geography of Russia. M., 2001.

Eastern Siberia occupies a vast territory from the Yenisei to the Pacific Ocean. It is famous for its large number of natural resources and minerals. The features of the relief and this region made it so valuable in terms of raw materials. Mineral resources of Eastern Siberia are not only oil, coal and iron ores. A significant part of Russia's gold and diamonds, as well as valuable metals, is mined here. In addition, almost half of the country's forest resources are located in this region.

Eastern Siberia

Minerals are not the only feature of this region. Eastern Siberia covers an area of more than 7 million square kilometers, which is about a quarter of the whole of Russia. It stretches from the valley of the Yenisei River to the most mountain ranges on the Pacific coast. The region borders the Arctic Ocean to the north and Mongolia and China to the south.

Eastern Siberia does not include as many regions and settlements as in the European part of Russia, because this area is considered sparsely populated. Here are the country's largest Chita and Irkutsk regions, as well as the Krasnoyarsk and Trans-Baikal regions. In addition, the autonomous republics of Yakutia, Tuva and Buryatia belong to Eastern Siberia.

Eastern Siberia: relief and minerals

The diversity of the geological structure of this region explains such a wealth of its raw materials. Due to their huge number, many deposits have not even been explored. What minerals are Eastern Siberia rich in? It is not only coal, oil and iron ores. The subsoil of the region contains rich reserves of nickel, lead, tin, aluminum and other metals, as well as sedimentary rocks necessary for industry. In addition, Eastern Siberia is the main supplier of gold and diamonds.

This can be explained by the features of the relief and geological structure of this region. Eastern Siberia is located on the ancient Siberian platform. And most of the territory of the region is occupied by the Central Siberian Plateau, elevated above sea level from 500 to 1700 m. The foundation of this platform is the oldest crystalline rocks, whose age reaches 4 million years. The next layer is sedimentary. It alternates with igneous rocks formed as a result of volcanic eruptions. Therefore, the relief of Eastern Siberia is folded, stepped. It contains many mountain ranges, plateaus, terraces, deep river valleys.

Such a variety of geological processes, tectonic shifts, deposits of sedimentary and igneous rocks led to the wealth of minerals in Eastern Siberia. The table allows you to find out that more resources are mined here than in neighboring regions.

Coal reserves

Due to geological processes since the Paleozoic and Mesozoic eras, the largest in Russia coal deposits of minerals in Western and Eastern Siberia are located in the lowlands of the region. These are the Lena and Tunguska basins. There are also a lot of smaller deposits. And although there is less coal in them, they are also promising. These are the Kama-Achinsk and Kolyma-Indigirsk basins, the Irkutsk, Minusinsk, South Yakut deposits.

Hard coal reserves in Eastern Siberia account for 80% of all coal mined in Russia. But many places of its occurrence are very difficult to develop due to the harsh climatic conditions of the region and the features of the relief.

Iron and copper ores

The main minerals of Eastern Siberia are metals. Their deposits are found in the most ancient rocks, even the Precambrian period. Most of all in the region are hematites and magnetites. Their deposits are located in the south of the Yakutsk region, in the basin on and also on the Angara, in Khakassia, Tuva and Transbaikalia.

The largest ore deposits are Korshunovskoye and Abakanskoye. There are also many of them in the Angara-Pitsky district. 10% of all Russian iron ore reserves are concentrated here. In Transbaikalia and in the north of the region there are also large deposits of tin and valuable metals.

The environs of Norilsk are famous for large deposits of copper-nickel ores. Almost 40% of Russian copper and about 80% of nickel are mined here. In addition, there is a lot of cobalt, there are also platinum, silver, tellurium, selenium and other elements. In other places, copper, mercury, manganese, antimony are mined. There are large deposits of bauxite.

Non-metallic minerals

Our country is the world's largest supplier of natural gas, and a lot of oil is produced here. And the first supplier of these minerals is the deposits of Eastern Siberia. In addition, geological processes have led to the emergence of rich deposits of sedimentary rocks.

Gold and diamonds of Eastern Siberia

The most valuable metal has been mined here for almost the second century. The oldest deposit is Bodaibo in the Irkutsk region. There are rich placer and bedrock deposits of gold in the Aldan, Yan, Allah-Yun regions. Deposits have recently begun to be developed in the region of the Yenisei Ridge, near Minussinsk and in the east of Transbaikalia.

Thanks to the special geological processes that have been going on in this region since the Mesozoic era, many diamonds are now being mined here. The largest deposit in Russia is located in Western Yakutia. They are mined from the so-called diatremes filled with kimberlites. Each such "explosion tube" in which diamonds are found even got its own name. The most famous are "Udachnaya-Vostochnaya", "Mir" and "Aikhal".

Natural resources

The complex topography of the region, vast undeveloped territories covered with taiga forests provide a wealth of natural resources. Due to the fact that the most full-flowing rivers of Russia flow here, the region is provided with cheap and environmentally friendly hydroelectric power. The rivers are rich in fish, the surrounding forests are rich in fur-bearing animals, of which sable is especially valued. But due to the fact that man has become more and more actively interfering with nature, many species of plants and animals are dying out. Therefore, many reserves and national parks have recently been created in the region to preserve natural wealth.

The richest areas

Eastern Siberia occupies almost a quarter of the territory of Russia. But there are not many people living here. In some places, there are more than 100 square kilometers per person. But Eastern Siberia is very rich in minerals and natural resources. Although they are unevenly distributed throughout the region.

The richest in economic terms is the Yenisei basin. Krasnoyarsk is located here, in which more than half of the entire population of Eastern Siberia is concentrated. The richness of this area in minerals, natural and hydro resources led to the active development of industry.
The wealth located in the upper reaches of the Angara River began to be used only in the 20th century. A very large polymetallic deposit has been discovered here. And the reserves of iron ore are simply huge. The best magnesites in Russia are mined here, as well as a lot of antimony, bauxites, nephelines, and slates. Deposits of clay, sand, talc and limestone are being developed.
Evenkia has the richest resources. Here in the Tunguska basin there are such minerals of Eastern Siberia as stone and high-quality graphite is mined in the Noginsk deposit. Icelandic spar deposits are also being developed.
Khakassia is another richest region. A quarter of East Siberian coal and all iron ore are mined here. After all, the Abakansky mine, located in Khakassia, is the largest and oldest in the region. There is gold, copper, a lot of building materials.
One of the richest places in the country is Transbaikalia. Mostly metals are mined here. For example, it supplies copper ores, Ononskoye - tungsten, Sherlokogonskoye and Tarbaldzheyskoye - tin, and Shakhtaminskoye and Zhrikenskoye - molybdenum. In addition, a lot of gold is mined in Transbaikalia.
Yakutia is a treasure trove of minerals in Eastern Siberia. Although only after the revolution, deposits of rock salt, coal and iron ore began to be developed. There are rich deposits of non-ferrous metals, mica. In addition, it is in Yakutia that the richest reserves of gold and diamonds have been discovered.

Problems of development of minerals

Huge, often unexplored territories of the region lead to the fact that many of its natural resources are not developed. There is a very low population density here, therefore, promising mineral deposits of Eastern Siberia are mainly developed in populated areas. After all, the lack of roads over a large area and the huge distance from the center make the development of deposits in remote regions unprofitable. In addition, most of Eastern Siberia is located in the permafrost zone. A sharply continental climate hinders the development of natural resources in the rest of the territory.

Northeastern Siberia and the Far East

Due to the peculiarities of the relief and climatic conditions, the minerals of North-Eastern Siberia are not so rich. There are few forests here, mainly tundra and arctic deserts. Most of the territory is dominated by permafrost and year-round low temperatures. Therefore, the minerals of North-Eastern Siberia are not very developed. Basically, coal is mined here, as well as metals - tungsten, cobalt, tin, mercury, molybdenum and gold.

The easternmost and northern regions of Siberia belong to the Far East. This area is also rich, but also more populated due to its proximity to the ocean and milder climate. Mineral resources of Eastern Siberia and the Far East are similar in many respects. There are also many diamonds, gold, tungsten and other non-ferrous metals, mercury, sulfur, graphite, mica are mined. The region has rich deposits of oil, coal and natural gas.

General characteristics of North-Eastern Siberia

To the east of the lower reaches of the Lena lies a vast territory, bounded in the east by the mountain ranges of the Pacific watershed. This physical and geographical country was named North-Eastern Siberia. Including the islands of the Arctic Ocean, North-Eastern Siberia covers an area of more than $1.5 million sq. km. Within its borders is the eastern part of Yakutia and the western part of the Magadan region. North-Eastern Siberia is located in high latitudes and is washed by the waters of the Arctic Ocean and its seas.

Cape Svyatoi Nos is the northernmost point. The southern regions are in the Mai River basin. Almost half of the country's territory is located north of the Arctic Circle, which is characterized by a diverse and contrasting relief. There are mountain ranges, plateaus, flat lowlands along the valleys of large rivers. Northeastern Siberia belongs to the Verkhoyansk-Chukotka Mesozoic folding, when the main folding processes took place. The modern relief was formed as a result of the latest tectonic movements.

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The climatic conditions of North-Eastern Siberia are severe, January frosts reach -$60$, -$68$ degrees. Summer temperature +$30$, +$36$ degrees. The temperature amplitude in some places is $100$-$105$ degrees, there is little precipitation, about $100$-$150$ mm. Permafrost fetters the soil to a depth of several hundred meters. On the flat territories, the distribution of soils and vegetation cover is well expressed in zonality - on the islands, the zone of arctic deserts, continental tundra and monotonous swampy larch woodlands. Altitudinal zonality is characteristic of mountainous regions.

Remark 1

Explorers I. Rebrov, I. Erastov, M. Stadukhin delivered the first information about the nature of North-Eastern Siberia. It was the middle of the $XVII$ century. The northern islands were studied by A.A. Bunge and E.V. Toll, but the information was far from complete. Only in the $30$ years of the expedition of S.V. Obruchev changed the ideas about the features of this physical and geographical country.

Despite the diversity of the relief, North-Eastern Siberia is mainly a mountainous country, lowlands occupy $20% of the area. The mountain systems of the outlying ranges of the Verkhoyansk, Chersky, Kolyma Uplands are located here. In the south of North-Eastern Siberia there are the highest mountains, the average height of which reaches $1500$-$2000$ m. whose height is $3147$ m.

Geological structure of the North-East of Siberia

In the Paleozoic era and at the beginning of the Mesozoic era, the territory of North-Eastern Siberia belonged to the Verkhoyansk-Chukotka geosynclinal marine basin. The main evidence of this is the thick Paleozoic-Mesozoic deposits, reaching $20$-$22 thousand meters in places, and strong tectonic movements, which created folded structures in the second half of the Mesozoic. The most ancient structural elements include the median massifs Kolyma and Omolon. A younger age - Upper Jurassic in the west, and Cretaceous in the east - have other tectonic elements.

These elements include:

Verkhoyansk folded zone and Sette - Dabansky atiklinorium;
Yanskaya and Indigirsko-Kolyma synclinal zones;
Tas-Khayakhtakhsky and Momsky anticlinoria.

By the end of the Cretaceous, northeastern Siberia was a territory elevated above neighboring regions. The warm climate of that time, and the denudation processes of mountain ranges leveled the relief and formed flat surfaces of leveling. The modern mountain relief was formed under the influence of tectonic uplifts in the Neogene and Quaternary period. The amplitude of these uplifts reached $1000$-$2000m. Cenozoic subsidences are occupied by lowlands and intermountain basins with strata of loose deposits.

Approximately from the middle of the Quaternary period, glaciation began, on mountain ranges that continued to rise, large valley glaciers appeared. The glaciation had an embryonic character, according to D.M. Kolosov, on the plains, firn fields formed here. The formation of permafrost begins in the second half of the Quaternary in the archipelago of the New Siberian Islands and in the coastal lowlands. The thickness of permafrost and ground ice reaches $50$-$60$ m in the cliffs of the Arctic Ocean.

Remark 2

The glaciation of the plains of northeastern Siberia was thus passive. A significant part of the glaciers were slow-moving formations that carried little loose material. The exaration impact of these glaciers had little effect on the relief.

Mountain-valley glaciation is better expressed, on the outskirts of mountain ranges there are well-preserved forms of glacial exaration - cirques, trough valleys. Valley Middle Quaternary glaciers reached a length of $200$-$300$ km. The mountains of North-Eastern Siberia, according to most experts, experienced three independent glaciations in the Middle Quaternary and Upper Quaternary.

These include:

Tobychanskoe glaciation;
Elga glaciation;
Bokhapcha glaciation.

The first glaciation led to the appearance of Siberian conifers, including Dahurian larch. During the second interglacial epoch, mountain taiga prevailed. It is typical for the southern regions of Yakutia at the present time. The last glaciation had almost no effect on the species composition of modern vegetation. The northern limit of the forest at that time, according to A.P. Vaskovsky, was noticeably shifted to the south.

The relief of the North-East of Siberia

The relief of North-Eastern Siberia forms several well-defined geomorphological tiers. Each stage is associated with a hypsometric position, which was determined by the nature and intensity of the latest tectonic movements. The position in high latitudes and the sharp continentality of the climate cause different altitudinal limits of the distribution of the corresponding types of mountainous relief. In its formation, the processes of nivation, solifluction, and frost weathering are of greater importance.

Within North-Eastern Siberia, in accordance with morphogenetic features, the following are distinguished:

Accumulative plains;
Erosion-denudation plains;
Plateau;
low mountains;
Mid-mountain and low-mountain alpine relief.

Separate areas of tectonic subsidence occupy accumulative plains, characterized by a slightly rugged relief and small fluctuations in relative height. Such forms are spreading, which owe their formation to permafrost processes, large ice content of loose deposits and thick underground ice.

Among them are:

Thermokarst basins;
Permafrost heaving mounds;
Frost cracks and polygons;
High ice cliffs on the sea coasts.

The accumulative plains include the Yano-Indigirskaya, Sredne-Indigirskaya, and Kolyma lowlands.

At the foot of a number of ridges - Anyuisky, Momsky, Kharaulakhsky, Kulara - formed erosion-denudation plains. The surface of the plains has a height of no more than $200$ m, but can reach $400$-$500$ m near the slopes of a number of ridges. Loose deposits here are thin and they are composed mainly of bedrock of different ages. As a result, gravel placers, narrow valleys with rocky slopes, low hills, spots-medallions, and solifluction terraces can be found here.

Between the Verkhoyansky ridge and the Chersky ridge there is a pronounced plateau terrain- Yanskoye, Elginskoye, Oymyakonskoye, Nerskoye plateaus. Most of the plateaus are composed of Mesozoic deposits. Their modern height is from $400$ to $1300$ m.

Those areas that were subjected to uplifts of moderate amplitude in the Quaternary are occupied low mountains, with a height of $300$-$500$ m. They occupy a marginal position and are dissected by a dense network of deep river valleys. Typical landforms for them are an abundance of stony placers and rocky peaks.

Middle mountain relief is mainly characteristic of most of the massifs of the Verkhoyansk Range system. Yudomo-May Highland, Chersky Ridge, Tas-Khayakhtakh, Momsky. In the Kolyma Highlands and the Anyui Range, there are also mid-mountain massifs. Their height is from $800$-$2200$ m. The mid-mountain massifs of North-Eastern Siberia are located in the mountain tundra, above the upper limit of woody vegetation.

High Alpine relief. These are the ridges of the highest mountain ranges - Suntar-Khayata, Ulakhan-Chistai, Tas-Khayakhtakh, etc. They are associated with the areas of the most intense uplifts of the Quaternary period. The height is more than $2000$-$2200$ m. The activity of Quaternary and modern glaciers plays a significant role in the formation of the Alpine relief, therefore large amplitudes of heights, deep dissection, narrow rocky ridges, cirques, cirques and other glacial landforms will be characteristic.

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Federal State Budgetary Educational Institution of Higher Professional Education "National Mineral and Raw Materials University "Gorny"

Faculty of secondary vocational education

(College of Geodesy and Cartography)

TEST

by geography

Option number 8

Completed:

1st year student of PG-15z group

FULL NAME. Konyaev Artur Georgievich

Lecturer: Dashicheva A.V.

St. Petersburg-2015

TASK 1: Biogenic landforms. Relief-forming activity of animals and plants.

TASK 2: North-Eastern Siberia of Russia, physical and geographical characteristics

The relief is a set of forms of the earth's surface, different in shape, size, origin, age and history of development. The relief influences the formation of the climate, the nature and direction of the flow of rivers depend on it, the features of the distribution of flora and fauna are associated with it. The relief significantly affects the life and economic activity of a person.

The significance of organisms in the life of the Earth is great and varied. The processes of changing the surface of the Earth as a result of the activity of living organisms are called biogeomorphological, and the relief created with the participation of plants and animals is called biogenic. These are mainly nano-, micro- and mesoforms of relief.

A grandiose process, carried out largely due to organisms, is the formation of sediments (for example, limestones, caustobioliths and other rocks).

Plants and animals are also involved in a complex universal process - the weathering of rocks, both as a result of direct impact on rocks, and due to their metabolic products. Not without reason, sometimes, along with physical and chemical weathering, biological weathering is distinguished.

Plants and animals have a significant impact on various natural processes, such as erosion. The destruction of vegetation on steep slopes, the trampling of plants by animals (the so-called "slaughter trails"), the loosening of soils by burrowing animals - all this increases erosion. This is especially dangerous on the mountain slopes, where distant pasture cattle breeding is carried out. There, due to excessive pasture load, various large-scale slope processes often come to life, the results of which are felt even in the foothills. Grassing of slopes (sowing meadow perennial long-rhizome grasses) holds soil together and reduces erosion.

Abundant aquatic vegetation in the rivers, as well as the inhabitants of water bodies, influence the channel processes. Beaver dams change the hydrological regime of rivers and geomorphological processes in the riverbed. Due to the damming of the rivers, swampy, hummocky floodplains are formed in the areas above the beaver dams.

Vegetation contributes to the overgrowth of lakes, filling them with organic matter. As a result, leveled hummocky surfaces of marshes appear on the site of lake basins. In the tundra, peat mounds are very characteristic.

Plants and animals are actively involved in the creation of some types of accumulative shores. In the equatorial-tropical latitudes, mangrove shores are formed, growing towards the sea due to the death of the plant mass. In temperate latitudes, along the shores of seas and lakes, reed shores similar to them arise.

On the coasts of the seas, shell beaches are created from animal shells with the participation of wave activity. Such accumulative landforms as coral structures are also widely known: coastal, barrier (for example, the Great Barrier Reef off the coast of Australia), ring atolls, which are numerous in the Pacific and Indian Oceans.

Burrowing animals also contribute to the formation of a biogenic relief. As a result of earth emissions, they create molehills, marmots, bobbins - mounds up to a meter high. Termite hills reach up to 4-5 m in height with a diameter of 15-20 m and create a kind of small-hilly relief in the Australian and African savannahs.

Animals and plants perform destructive work, which is often much more diverse and complex than the similar activity of various agents of inanimate nature (wind, water, etc.).

The accumulative activity of animals and plants causes a wide variety of positive landforms. You can, for example, point to marmot bumps, which are ejections of soil from holes. However, the largest positive landforms are formed due to the accumulation of plant residues in the form of peat. Ridges composed of peat are often found on the surface of raised bogs. Together with the depressions separating them (hollows), they create a kind of ridge-hollow surface of the marshes. The height of the ridges above the surface of the hollows ranges from 15 to 30 cm and rarely reaches 50-70 cm.

As a result of the vital activity of animals and plants, various forms of relief arise, which can be divided into the following main groups:

landforms due to their destructive activity;

landforms due to their accumulative activity.

Seven-Eastern Siberia is located in the extreme northeast of Eurasia at the junction of three lithospheric plates - Eurasian, North American and Pacific, which determined the extremely complex relief of the territory. In addition, over the course of a long geological history, cardinal rearrangements of tecto- and morphogenesis have repeatedly occurred here.

If we accept that the territory of North-Eastern Siberia corresponds to the late Mesozoic Verkhoyansk-Chukotka fold-cover region, then its boundaries are: in the west - the Lena valley and the lower reaches of the Aldan, from where, crossing the Dzhugdzhur, the border goes to the Sea of Okhotsk; in the southeast, the border runs along the lowland from the mouth of the Anadyr to the mouth of the Penzhina; in the north - the seas of the Arctic Ocean; in the south and east - the seas of the Pacific Ocean. Some geographers do not include the Pacific coast in North-Eastern Siberia, drawing the boundary along the watershed of the rivers of the basins of the Arctic and Pacific Oceans.

In the Precambrian and Paleozoic, median massifs appeared in this area in the form of individual microcontinents (Kolyma-Omolon and others), which during the Mesozoic folding were woven into the lace of folded mountains. At the end of the Mesozoic, the territory experienced peneplanization. At that time, there was an even warm climate with coniferous-broad-leaved forests, and North American flora penetrated here by land on the site of the Bering Strait. During the Alpine folding, the Mesozoic structures were split into separate blocks, some of which rose and others sank. The median massifs rose entirely, and where they split, lava came out. At the same time, the shelf of the Arctic Ocean sank and the relief of North-Eastern Siberia acquired the appearance of an amphitheater. Its highest steps run along the western, southern, and eastern borders of the territory (Verkhoyansk Range, Suntar-Khayata, and the Kolyma Highlands). A step below are numerous plateaus on the site of the median massifs (Yanskoye, Elginskoye, Yukagirskoye, etc.) and the Chersky Range with the highest point of North-Eastern Siberia - Mount Pobeda (3003 m). The lowest step is the marshy Yano-Indigirskaya and Kolyma lowlands.

Arctic desert zone.

Tundra zone.

Taiga zone.

The Arctic desert is part of the Arctic geographical zone, the basin of the Arctic Ocean. This is the northernmost of the natural zones, characterized by an arctic climate. The spaces are covered with glaciers, rubble and stone fragments.

It has low air temperatures in winter up to? 60 ° C, on average - 30 ° C in January and +3 ° C in July. It is formed not only due to the low temperatures of high latitudes, but also due to the reflection of heat (albedo) in the daytime from the snow and under the ice crust. The annual amount of atmospheric precipitation is up to 400 mm. In winter, the soil is saturated with layers of snow and barely thawed ice, the level of which is 75-300 mm. [Source not specified 76 days]

The climate in the Arctic is very harsh. Ice and snow cover lasts almost the whole year. In winter, there is a long polar night (at 75 ° N - 98 days; at 80 ° N - 127 days; in the region of the pole - half a year). This is a very harsh time of the year. The temperature drops to −40 °C and below, strong gale-force winds blow, snowstorms are frequent. In summer, there is round-the-clock lighting, but there is little heat, the soil does not have time to completely thaw. The air temperature is slightly above 0 °C. The sky is often overcast with gray clouds, it rains (often with snow), due to the strong evaporation of water from the surface of the ocean, thick fogs form.

Flora and fauna

The Arctic desert is practically devoid of vegetation: there are no shrubs, lichens and mosses do not form a continuous cover. The soils are thin, with patchy (island) distribution mainly only under vegetation, which consists mainly of sedges, some grasses, lichens and mosses. Extremely slow recovery of vegetation. The fauna is predominantly marine: walrus, seal, in summer there are bird colonies. Terrestrial fauna is poor: arctic fox, polar bear, lemming.

Tumndra is a type of natural zones lying beyond the northern limits of forest vegetation, an area with permafrost soil that is not flooded by sea or river waters. The tundra is located north of the taiga zone. By the nature of the surface of the tundra are swampy, peaty, rocky. The southern border of the tundra is taken as the beginning of the Arctic. From the north, the tundra is limited by the zone of arctic deserts. Sometimes the term "tundra" is applied to similar natural areas of Antarctica.

Tundra in Alaska in July

The tundra is characterized by a very harsh climate (the climate is subarctic), only those plants and animals that can endure cold and strong winds live here. In the tundra, large fauna is quite rare.

Winter in the tundra is extremely long. Since most of the tundra is located beyond the Arctic Circle, the tundra experiences a polar night in winter. The severity of winter depends on the continentality of the climate.

The tundra, as a rule, is deprived of climatic summer (or it comes for a very short time). The average temperature of the warmest month (July or August) in the tundra is 5-10 °C. With the advent of summer, all vegetation comes to life, as the polar day comes (or white nights in those areas of the tundra where the polar day does not occur).

May and September are the spring and autumn of the tundra. It is in May that the snow cover melts, and already in early October it usually sets again.

In winter, the average temperature is up to? 30 ° C

There can be 8-9 winter months in the tundra.

Animal and plant world

The vegetation of the tundra is primarily lichens and mosses; the angiosperms encountered are low grasses (especially from the Grass family), shrubs and shrubs (for example, some dwarf species of birch and willow, berry bushes, princess, blueberry).

Typical inhabitants of the Russian tundra are reindeer, foxes, bighorn sheep, wolves, lemmings and hare. There are few birds: Lapland plantain, white-winged plover, red-throated pipit, plover, snow bunting, snowy owl and ptarmigan.

Rivers and lakes are rich in fish (nelma, broad whitefish, omul, vendace and others).

The swampiness of the tundra allows the development of a large number of blood-sucking insects that are active in the summer. Due to the cold summer, there are practically no reptiles in the tundra: low temperatures limit the ability of cold-blooded animals to live.

Taigam is a biome characterized by the predominance of coniferous forests (boreal species of spruce, fir, larch, pine, including cedar).

Pinezhsky forest.

The taiga is characterized by the absence or weak development of undergrowth (since there is little light in the forest), as well as the monotony of the grass-shrub layer and moss cover (green mosses). Shrub species (juniper, honeysuckle, currant, etc.), dwarf shrubs (blueberries, lingonberries, etc.) and herbs (oxalis, wintergreen) are not numerous both in Eurasia and in North America.

In the north of Europe (Finland, Sweden, Norway, Russia) spruce forests predominate, in North America (Canada) - spruce forests with an admixture of Canadian larch. The taiga of the Urals is characterized by light coniferous forests of Scots pine. In Siberia and the Far East, sparse larch taiga dominates with an undergrowth of elfin cedar, Dahurian rhododendron, and more.

The fauna of the taiga is richer and more diverse than that of the tundra. Numerous and widespread: lynx, wolverine, chipmunk, sable, squirrel, etc. Of the ungulates, there are reindeer and red deer, elk, roe deer; hares, shrews, rodents are numerous: mice, voles, squirrels and flying squirrels. Of the birds, the following are common: capercaillie, common hazel grouse, nutcracker, crossbills, etc. The taiga of North America is typical of American species of the same genera as in Eurasia.

In the taiga forest, in comparison with the forest-tundra, the conditions for the life of animals are more favorable. There are more settled animals here. Nowhere in the world, except for the taiga, there are so many fur-bearing animals.

In winter, the vast majority of invertebrate species, all amphibians and reptiles, as well as some mammalian species, plunge into suspended animation and hibernation, and the activity of a number of other animals decreases.

Taiga types

According to the species composition, light coniferous (Scots pine, some American species of pine, Siberian and Dahurian larch) and more characteristic and widespread dark coniferous taiga (spruce, fir, stone pine, Korean cedar) are distinguished. Tree species can form pure (spruce, larch) and mixed (spruce-fir) forest stands.

The soil is usually sod-podzolic. Humidity is sufficient. 1-6% humus.

Evaporation 545 mm, precipitation 550 mm, average temperature in July 17°-20 °C, in winter the average temperature in January in the west? 6 °C, and in the east? 13 °C

A sharply continental climate operates on the territory of North-Eastern Siberia. Almost all of North-Eastern Siberia lies within the Arctic and subarctic climatic zones. The temperature is on average below? 10 °.

North-Eastern Siberia can be divided into 3 climatic zones.

Hydrography

Northeastern Siberia is dissected by a network of many rivers flowing to the Laptev and East Siberian seas. The largest on them - Yana, Indigirka and Kolyma - flow almost in a meridional direction from south to north. Cutting through mountain ranges in narrow deep valleys and receiving numerous tributaries here, they, already in the form of high-water streams, go to the northern lowlands, where they acquire the character of flat rivers.

Most of the rivers are fed mainly by melting snow cover in early summer and summer rains. Groundwater, melting of snow and glaciers in high mountains, as well as icings, play a certain role in feeding the rivers. More than 70% of the annual river flow falls on three calendar summer months.

The largest river in North-Eastern Siberia - Kolyma (basin area - 643 thousand km2, length - 2129 km) - begins in the Upper Kolyma Highlands. Somewhat below the mouth of the Korkodon River, the Kolyma enters the Kolyma Lowland; its valley widens sharply here, the fall and speed of the current decrease, and the river gradually acquires a flat appearance. Near Nizhnekolymsk, the width of the river reaches 2-3 km, and the average annual discharge is 3900 m3/sec (flow of about 123 km3 of water).

The sources of the second major river - the Indigirka (length - 1980 km, basin area - 360 thousand km2) - are located in the region of the Oymyakon Plateau. Crossing the Chersky Range, it flows in a deep and narrow valley with almost steep slopes; rapids are often found here in the channel of the Indigirka. Then the river enters the plain of the Sredneindigirskaya lowland, where it breaks into branches separated by sandy islands. Below the village of Chokurdakh, the delta begins, with an area of 7700 km2. Indigirka has a runoff of more than 57 km3 per year (an average annual flow is 1800 m3/sec).

The western regions of the country are drained by Yana (length - 1490 km2, basin area - 238 thousand km2). Its sources - the Dulgalakh and Sartang rivers - flow down from the northern slope of the Verkhoyansk Range. After their confluence within the Yan Plateau, the river flows in a wide valley with well-developed terraces. In the middle part of the current, where the Yana crosses the spurs of the mountain ranges, its valley narrows, and rapids appear in the channel. The lower reaches of the Yana are located on the territory of the coastal lowland; when it flows into the Laptev Sea, the river forms a large delta (about 5200 km2 in area).

Yana is characterized by long summer floods, which is due to the gradual melting of snow cover in the mountainous regions of its basin and the abundance of summer rains. The highest water levels are observed in July and August. The average annual discharge is 1000 m3/s, and the runoff per year is over 31 km3.

Most of the lakes of North-Eastern Siberia are located on the northern plains, in the basins of the Indigirka and Alazeya. Here there are places where the area of the lakes is not less than the area of the land separating them. The abundance of lakes, of which there are several tens of thousands, is due to the small ruggedness of the lowland relief, difficult runoff conditions, and the widespread permafrost. Most often, lakes occupy thermokarst basins or depressions in floodplains and on river islands. All of them are distinguished by their small size, flat banks, shallow depths (up to 4-7 m). For seven to eight months, the lakes are bound by a powerful ice cover; very many of them freeze to the bottom in the middle of winter.

On the territory of North-Eastern Siberia there is: gold, tin, polymetals, tungsten, mercury, molybdenum, antimony, cobalt, arsenic, coal.

Unlike other parts of Siberia, the amount of high-quality timber here is relatively small.

relief siberia russia

Literature

1. Lyubushkina S.G. General geography: Proc. allowance for university students enrolled in special. "Geography" / S.G. Lyubushkina, K.V. pashkang, A.V. Chernov; Ed. A.V. Chernov. - M. : Education, 2004. - 288 p.

2. N. A. Gvozdetsky and N. I. Mikhailov, Physical Geography of the USSR. Asian part. - 3rd ed., Rev. and additional Textbook for students geogr. fak. Univ. - M.: "Thought", 1978. 512 p.

3. Davydova M.I., Rakovskaya E.M. Physical geography of the USSR. - M.: Enlightenment, 1990.- 304 p.

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Remark 1

Geological structure of the North-East of Siberia

These elements include:

Verkhoyansk folded zone and Sette - Dabansky atiklinorium;
Yanskaya and Indigirsko-Kolyma synclinal zones;
Tas-Khayakhtakhsky and Momsky anticlinoria.

Remark 2

These include:

Tobychanskoe glaciation;
Elga glaciation;
Bokhapcha glaciation.

The relief of the North-East of Siberia

Within North-Eastern Siberia, in accordance with morphogenetic features, the following are distinguished:

Accumulative plains;
Erosion-denudation plains;
Plateau;
low mountains;
Mid-mountain and low-mountain alpine relief.

Among them are:

Thermokarst basins;
Permafrost heaving mounds;
Frost cracks and polygons;
High ice cliffs on the sea coasts.

The accumulative plains include the Yano-Indigirskaya, Sredne-Indigirskaya, and Kolyma lowlands.

Eastern Siberia

Eastern Siberia: relief and minerals

Coal reserves

Iron and copper ores

Non-metallic minerals

Gold and diamonds of Eastern Siberia

Natural resources

The richest areas

Problems of development of minerals

Northeastern Siberia and the Far East

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Geological structure of the North-East of Siberia

The relief of the North-East of Siberia

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