As a result, plains are formed. Plains: characteristics and types. Plains, their classification. Division of plains by absolute height. Landforms associated with continental glaciation

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Plains– vast areas of the earth’s surface with small (up to 200 m) fluctuations in height and slight slopes.

Plains occupy 64% of the land area. Tectonically, they correspond to more or less stable platforms that have not shown significant activity in recent times, regardless of their age - whether they are ancient or young. Most of the land's plains are located on ancient platforms (42%).

Based on the absolute height of the surface, plains are distinguished negative– lying below the level of the World Ocean (Caspian region), low-lying– from 0 to 200 m altitude (Amazonian, Black Sea, Indo-Gangetic lowlands, etc.), sublime– from 200 to 500 m (Central Russian, Valdai, Volga Uplands, etc.). Plains also include plateau(high plains), which, as a rule, are located above 500 m and are separated from the adjacent plains by ledges (for example, the Great Plains in the USA, etc.). The depth and degree of dissection of them by river valleys, gullies and ravines depends on the height of the plains and plateaus: the higher the plains, the more intensely they are dissected.

In terms of appearance, plains can be flat, wavy, hilly, stepped, and in terms of the general slope of the surface - horizontal, inclined, convex, concave.

The different appearance of the plains depends on their origin and internal structure, which largely depend on the direction of neotectonic movements. Based on this feature, all plains can be divided into two types - denudation and accumulation (see diagram 1). Within the former, the processes of denudation of loose material predominate, and within the latter, its accumulation.

It is clear that denudation surfaces have experienced upward tectonic movements for most of their history. It was thanks to them that the processes of destruction and demolition - denudation - prevailed here. However, the duration of denudation may vary, and this is also reflected in the morphology of such surfaces.

With continuous or almost continuous slow (epeirogenic) tectonic uplift, which continued throughout the entire existence of the territories, there were no conditions for the accumulation of sediments. There was only a denudation of the surface by various exogenous agents, and if thin continental or marine sediments accumulated for a short time, then during subsequent uplifts they were carried out of the territory. Therefore, in the structure of such plains, an ancient base comes to the surface - folds cut off by denudation, only slightly covered by a thin cover of Quaternary deposits. Such plains are called basement; It is easy to see that the basement plains tectonically correspond to the shields of ancient platforms and the protrusions of the folded foundation of young platforms. Basement plains on ancient platforms have a hilly topography, most often they are elevated. These are, for example, the plains of Fennoscandia - the Kola Peninsula and Karelia. Similar plains are located in northern Canada. Basement hills are widespread in Africa. As a rule, long-term denudation has cut off all the structural irregularities of the base, so such plains are astructural.

The plains on the “shields” of young platforms have a more “restless” hilly topography, with residual hill-type elevations, the formation of which is associated either with lithological features - harder stable rocks, or with structural conditions - former convex folds, microhorsts or exposed intrusions. Of course, they are all structurally determined. This is what, for example, the Kazakh small hills and part of the Gobi plains look like.

The plates of ancient and young platforms, which experience a stable uplift only during the neotectonic stage of development, are composed of layers of sedimentary rocks of great thickness (hundreds of meters and a few kilometers) - limestones, dolomites, sandstones, siltstones, etc. Over millions of years, the sediments hardened, became rocky and acquired stability to erosion. These rocks lie more or less horizontally, as they were once deposited. Uplifts of territories during the neotectonic stage of development stimulated denudation on them, which did not allow young loose rocks to be deposited there. Plains on slabs of ancient and young platforms are called reservoir. From the surface, they are often covered with loose Quaternary continental sediments of low thickness, which practically do not affect their height and orographic features, but determine their appearance due to morphosculpture (East European, southern part of West Siberian, etc.).

Since strata plains are confined to platform plates, they are clearly structural - their macro- and even mesoforms of relief are determined by the geological structures of the cover: the nature of the bedding of rocks of varying hardness, their slope, etc.

During the Pliocene-Quaternary subsidence of territories, even relative ones, sediments carried away from surrounding areas began to accumulate on them. They filled in all the previous surface irregularities. This is how they were formed accumulative plains, composed of loose, Pliocene-Quaternary sediments. These are usually low-lying plains, sometimes even below sea level. According to the conditions of sedimentation, they are divided into marine and continental - alluvial, aeolian, etc. An example of accumulative plains are the Caspian, Black Sea, Kolyma, Yana-Indigirskaya lowlands composed of marine sediments, as well as the Pripyat, Leno-Vilyui, La Plata, etc. Accumulative Plains, as a rule, are confined to syneclises.

In large basins among the mountains and at their feet, accumulative plains have a surface inclined from the mountains, cut through by the valleys of many rivers flowing from the mountains and complicated by their alluvial cones. They are composed of loose continental sediments: alluvium, proluvium, colluvium, and lake sediments. For example, the Tarim Plain is composed of sands and loess, the Dzungarian Plain is composed of powerful sand accumulations brought from neighboring mountains. The ancient alluvial plain is the Karakum desert, composed of sands brought by rivers from the southern mountains in the pluvial era of the Pleistocene.

The morphostructures of plains usually include ridges These are linearly elongated hills with rounded peaks, usually no more than 500 m high. They are composed of dislocated rocks of different ages. An indispensable feature of a ridge is the presence of a linear orientation, inherited from the structure of the folded region in which the ridge arose, for example the Timan, Donetsk, Yenisei.

It should be noted that all of the listed types of plains (basement, strata, accumulative), as well as plateaus, plateaus and ridges, according to I. P. Gerasimov and Yu. A. Meshcheryakov, are not morphographic concepts, but morphostructural ones, reflecting the relationship of relief with geological structure.

Plains on land form two latitudinal series corresponding to the platforms of Laurasia and Gondwana. Northern Plains Row formed within the relatively stable ancient North American and East European platforms in recent times and the young epi-Paleozoic West Siberian platform - a plate that experienced even slight subsidence and is expressed in relief as a predominantly low-lying plain.

The Central Siberian Plateau, and in the morphostructural sense these are high plains - plateaus, formed on the site of the ancient Siberian Platform, activated in recent times due to resonant movements from the east, from the active geosynclinal Western Pacific belt. The so-called Central Siberian Plateau includes volcanic plateaus(Putorana and Syverma), tuffaceous plateaus(Central Tunguska), trap plateaus(Tungusskoye, Vilyuiskoye), reservoir plateaus(Priangarskoe, Prilenskoe), etc.

The orographic and structural features of the northern plains are unique: low coastal accumulative plains predominate beyond the Arctic Circle; to the south, along the so-called active 62° parallel, there is a strip of basement hills and even plateaus on the shields of ancient platforms - Laurentian, Baltic, Anabar; in middle latitudes along 50° N. w. - again a strip of stratal and accumulative lowlands - North German, Polish, Polesie, Meshchera, Sredneobskaya, Vilyuiskaya.

On the East European Plain, Yu.A. Meshcheryakov also identified another pattern: the alternation of lowlands and hills. Since the movements on the East European Platform were wave-like in nature, and their source in the neotectonic stage was collisions of the Alpine belt, he established several alternating stripes of hills and lowlands, fanning out from the southwest to the east and taking an increasingly meridional direction as they move away from the Carpathians . The Carpathian strip of uplands (Volyn, Podolsk, Prydneprovskaya) is replaced by the Pripyat-Dnieper strip of lowlands (Pripyat, Prydneprovskaya), followed by the Central Russian strip of uplands (Belarusian, Smolensk-Moscow, Central Russian); the latter is successively replaced by the Upper Volga-Don strip of lowlands (Meshchera lowland, Oka-Don plain), then by the Volga upland, Trans-Volga lowland and, finally, by a strip of the Cis-Ural uplands.

In general, the plains of the northern series are inclined to the north, which is consistent with the flow of the rivers.

Southern Plains Row corresponds to the Gondwana platforms, which have experienced activation in recent times. Therefore, elevations predominate within its boundaries: stratum (in the Sahara) and basement (in southern Africa), as well as plateaus (Arabia, Hindustan). Only within the inherited troughs and syneclises did stratal and accumulative plains form (Amazonian and La Plata lowlands, the Congo depression, the Central Lowland of Australia).

In general, the largest areas among the plains on the continents belong to strata plains, within which the primary plain surfaces are formed by horizontally lying layers of sedimentary rocks, and the basement and accumulative plains are of subordinate importance.

In conclusion, we emphasize once again that mountains and plains, as the main forms of relief on land, are created by internal processes: mountains gravitate towards mobile folded belts

Earth, and plains - to platforms (Table 14). Relatively small, relatively short-lived relief forms created by external exogenous processes are superimposed on large ones and give them a unique appearance. They will be discussed below.

A plain is a type of relief that is a flat, vast space. More than two-thirds of Russia's territory is occupied by plains. They are characterized by a slight slope and slight fluctuations in terrain heights. A similar relief is found on the bottom of sea waters. The territory of the plains can be occupied by any: deserts, steppes, mixed forests, etc.

Map of the largest plains in Russia

Most of the country is located on a relatively flat type of terrain. Favorable ones allowed a person to engage in cattle breeding, build large settlements and roads. It is easiest to carry out construction activities on the plains. They contain many minerals and others, including, and.

Below are maps, characteristics and photos of landscapes of the largest plains in Russia.

the East European Plain

East European Plain on the map of Russia

The area of the East European Plain is approximately 4 million km². The natural northern border is the White and Barents Seas; in the south, the lands are washed by the Azov and Caspian Seas. The Vistula River is considered the western border, and the Ural Mountains - the eastern border.

At the base of the plain lies the Russian platform and the Scythian plate; the foundation is covered by sedimentary rocks. Where the base is raised, hills have formed: the Dnieper, Central Russian, and Volga. In places where the foundation is deeply sunk, lowlands lie: Pechora, Black Sea, Caspian.

The territory is located at moderate latitude. Atlantic air masses penetrate the plain, bringing with them precipitation. The western part is warmer than the east. The minimum temperature in January is -14˚C. In summer, the air from the Arctic gives coolness. The largest rivers flow south. Short rivers, Onega, Northern Dvina, Pechora, are directed to the north. The Neman, Neva and Western Dvina carry water in a westerly direction. In winter they all freeze. In spring, floods begin.

Half of the country's population lives on the East European Plain. Almost all forest areas are secondary forest, there are a lot of fields and arable lands. There are many mineral deposits in the area.

West Siberian Plain

West Siberian Plain on the map of Russia

The area of the plain is about 2.6 million km². The western border is the Ural Mountains, in the east the plain ends with the Central Siberian Plateau. The Kara Sea washes the northern part. The Kazakh small sandpiper is considered the southern border.

The West Siberian plate lies at its base, and sedimentary rocks lie on the surface. The southern part is higher than the northern and central. The maximum height is 300 m. The edges of the plain are represented by the Ket-Tym, Kulunda, Ishim and Turin plains. In addition, there are the Lower Yisei, Verkhnetazovskaya and North Sosvinskaya uplands. Siberian ridges are a complex of hills in the west of the plain.

The West Siberian Plain lies in three regions: arctic, subarctic and temperate. Due to low pressure, Arctic air penetrates the territory, and cyclones are actively developing in the north. Precipitation is unevenly distributed, with the maximum amount falling in the middle part. Most precipitation falls between May and October. In the southern zone, thunderstorms often occur in summer.

The rivers flow slowly, and many swamps have formed on the plain. All reservoirs are flat in nature and have a slight slope. The Tobol, Irtysh and Ob originate in mountainous areas, so their regime depends on the melting of ice in the mountains. Most reservoirs have a northwestern direction. In spring there is a long flood.

Oil and gas are the main riches of the plain. In total there are more than five hundred deposits of combustible minerals. In addition to them, in the depths there are deposits of coal, ore and mercury.

The steppe zone, located in the south of the plain, is almost completely plowed. Fields of spring wheat are located on black soil. Plowing, which lasted for many years, led to the formation of erosion and dust storms. In the steppes there are many salt lakes, from which table salt and soda are extracted.

Central Siberian Plateau

Central Siberian Plateau on the map of Russia

The area of the plateau is 3.5 million km². In the north it borders on the North Siberian Lowland. The Eastern Sayan Mountains are a natural border in the south. In the west, the lands begin at the Yenisei River, in the east they end at the Lena River valley.

The plateau is based on the Pacific lithospheric plate. Because of it, the earth's crust rose significantly. The average heights are 500 m. The Putorana plateau in the north-west reaches 1701 m in height. The Byrranga Mountains are located in Taimyr, their height exceeds a thousand meters. In Central Siberia there are only two lowlands: North Siberian and Central Yakut. There are many lakes here.

Most of the territories are located in the Arctic and subarctic zones. The plateau is fenced off from warm seas. Due to the high mountains, precipitation is distributed unevenly. They fall in large numbers in the summer. The earth cools greatly in winter. The minimum temperature in January is -40˚C. Dry air and lack of winds help to endure such difficult conditions. During the cold season, powerful anticyclones form. There is little precipitation in winter. In summer, cyclonic weather sets in. The average temperature during this period is +19˚C.

The largest rivers, the Yenisei, Angara, Lena, and Khatanga, flow through the lowland. They cross faults in the earth's crust, so they have many rapids and gorges. All rivers are navigable. Central Siberia has enormous hydropower resources. Most of the major rivers are located in the north.

Almost the entire territory is located in the zone. The forests are represented by larch trees, which shed their needles for the winter. Pine forests grow along the Lena and Angara valleys. The tundra contains shrubs, lichens and mosses.

Siberia has a lot of mineral resources. There are deposits of ore, coal, and oil. Platinum deposits are located in the southeast. There are salt deposits in the Central Yakut Lowland. There are graphite deposits on the Nizhnyaya Tunguska and Kureyka rivers. Diamond deposits are located in the northeast.

Due to difficult climatic conditions, large settlements are located only in the south. Human economic activity is concentrated in the mining and logging industries.

Azov-Kuban Plain

Azov-Kuban Plain (Kuban-Azov Lowland) on the map of Russia

The Azov-Kuban Plain is a continuation of the East European Plain, its area is 50 thousand km². The Kuban River is the southern border, and the northern one is the Yegorlyk River. In the east, the lowland ends in the Kuma-Manych depression, the western part opens to the Sea of Azov.

The plain lies on the Scythian plate and is a virgin steppe. The maximum height is 150 m. The large rivers Chelbas, Beysug, Kuban flow in the central part of the plain, and there is a group of karst lakes. The plain is located in the continental belt. Warm ones soften the local climate. In winter, temperatures rarely drop below -5˚C. In summer the thermometer shows +25˚C.

The plain includes three lowlands: Prikubanskaya, Priazovskaya and Kuban-Priazovskaya. Rivers often flood populated areas. There are gas fields in the territory. The region is famous for its chernozem fertile soils. Almost the entire territory has been developed by humans. People grow cereals. The diversity of flora has been preserved only along rivers and in forests.

Plains are areas of the land surface, the bottom of oceans and seas, characterized by slight fluctuations in height (up to 200 m, slopes less than 5°). According to the structural principle, plains of platform and orogenic (mountain) regions are distinguished (mainly within intermountain and foothill troughs); according to the predominance of certain external processes - denudation, formed as a result of the destruction of elevated relief forms, and accumulative, resulting from the accumulation of layers of loose sediments. Collectively, the plains occupy most of the Earth's surface, 15-20% of the land. The largest plain in the world is the Amazon (over 5 million sq. km).

Numerous types of plains are distinguished by the nature and height of the surface, geological structure, origin and history of development. Depending on the appearance and size of the irregularities, they are distinguished: flat, wavy, ridged, stepped plains. Based on the shape of the surface, horizontal plains (the Great Chinese Plain), sloping plains (mainly foothills), and concave plains (in the intermountain depressions - the Tsaidam Basin) are distinguished.

The classification of plains by height relative to sea level is widespread. Negative plains are located below sea level, often in deserts, for example, the Qattara Depression or the lowest place on land - the Ghor Depression (up to 395 m below sea level). Lowland plains, or lowlands (altitudes from 0 to 200 m above sea level), include the world's greatest plains: the Amazonian Plain, the East European Plain and the West Siberian Plain. The surface of elevated plains, or hills, is located in the altitude range of 200-500 m (Central Russian Upland, Valdai Upland). Mountain plains rise above 500 m, for example, one of the largest in Central Asia - Gobi. The term plateau is often applied to both elevated and upland plains with a flat or undulating surface separated by slopes or ledges from lower neighboring areas.

The appearance of the plain depends largely on external processes. Based on the amount of influence of external processes, plains are divided into accumulative and denudative. Accumulative plains, formed by the accumulation of layers of loose sediments (accumulation), are river (alluvial), lake, sea, ash, glacial, and water-glacial. For example, the thickness of sediments, mainly river and sea, on the Flanders Lowland (North Sea coast) reaches 600 m, and the thickness of silty rocks (loess) on the Loess Plateau is 250-300 m. Accumulative plains also include volcanic plateaus composed of solidified lavas and loose products of volcanic eruptions (Dariganga Plateau in Mongolia, Columbia Plateau in North America).

Denudation plains arose as a result of the destruction of ancient hills or mountains and the removal of the resulting material by water and wind (denudation). Depending on the predominant process due to which the ancient relief was destroyed and the surface leveled, erosional (with the predominance of the activity of flowing waters), abrasion (created by wave processes on the sea coasts), deflationary (leveled by the wind) and other denudation plains are distinguished. Many plains have complex origins, as they were formed by various processes. Depending on the mechanism of formation, denudation plains are divided into: peneplains - in this case, the removal and demolition of material occurred more or less evenly from the entire surface of ancient mountains, for example, the Kazakh small hills or the Tien Shan syrts; pediplains that arise from the destruction of previously elevated relief, which begins from the outskirts (many plains at the foot of the mountains, mainly deserts and savannas of Africa).

The participation of tectonic processes in the formation of plains can be either passive or active. With passive participation, the main role in the formation of structural plains is played by a fairly even - horizontal or inclined (monoclinal) - occurrence of rock layers (Turgai Plateau). Many structural plains are simultaneously accumulative, for example, the Caspian Lowland, the North German Lowland. When denudation predominates in the formation of structural plains, stratified plains are distinguished (Swabian-Franconian Jura). What differs from them are the basement plains, developed in dislocated rocks (Lake Plateau in Finland). During intermittent tectonic uplifts, followed by a period of rest sufficient to destroy and level the relief, tiered plains are formed, for example, the Great Plains.

Platform plains are formed in areas of relatively quiet tectonic and magmatic activity. These include most of the plains, including the largest ones. The plains of orogenic regions (see orogen) are distinguished by intense activity of the earth's interior. These are the plains of intermountain basins (Fergana Valley) and foothill troughs (Podolsk Upland). Sometimes the plains are considered parts of the so-called lowland countries - vast spaces where there are small areas with highly dissected relief (for example, Zhiguli on the Russian Plain - a flat country).

Earth's surface. On land, plains occupy about 20% of the area, the most extensive of which are confined to and. All plains are characterized by small fluctuations in elevation and slight slopes (slopes reach 5°). Based on absolute height, the following plains are distinguished: lowlands - they range from 0 to 200 m (Amazonian);

elevations - from 200 to 500 m above ocean level (Central Russian);
mountainous, or plateaus - over 500 m above sea level ();
the plains lying below ocean level are called depressions (Caspian).

According to the general nature of the surface of the plain, there are horizontal, convex, concave, flat, and hilly.

Based on the origin of the plains, the following types are distinguished:

marine accumulative(cm. ). Such, for example, is the lowland with its sedimentary cover of young marine strata;
continental accumulative. They were formed as follows: at the foot of the mountains, the products of destruction carried out from them by streams of water are deposited. Such plains have a slight slope to sea level. These most often include regional lowlands;
river accumulative. They are formed due to the deposition and accumulation of loose rocks brought in ();
abrasion plains(see Abrasia). They arose as a result of the destruction of coastlines by sea activity. These plains arise the faster the weaker the rocks and the more frequent the waves;
structural plains. They have a very complex origin. In the distant past they were mountainous countries. Over the course of millions of years, the mountains were destroyed by external forces, sometimes to the stage of almost plains (peneplains), then, as a result, cracks and faults appeared, along which water flowed to the surface; it, like armor, covered the previous unevenness of the relief, while its own surface remained flat or stepped as a result of the outpouring of traps. These are structural plains.

The surface of the plains, which receive sufficient moisture, is dissected by river valleys, dotted with complex systems of gullies and.

The study of the origin of the plains and the modern forms of their surface is of very important economic importance, since the plains are densely populated and developed by humans. They contain many settlements, a dense network of communication routes, and large farmlands. Therefore, it is with plains that one has to deal with when developing new territories, designing the construction of settlements, communications routes, and industrial enterprises. As a result of human economic activity, the topography of the plains can change significantly: ravines are filled in, embankments are built, quarries are formed during open-pit mining, and man-made hills of waste rock - waste heaps - grow near mines.

Changes in the relief of ocean plains are influenced by:

, eruptions, faults in the earth's crust. The irregularities they create are transformed by external processes. Sedimentary rocks settle to the bottom and level it. It accumulates most at the foot of the continental slope. In the central parts of the ocean, this process occurs slowly: over a thousand years, a layer of 1 mm is created;
natural currents that erode and transport loose rocks sometimes form underwater dunes.

The largest plains on Earth

Plains- vast areas of the earth's surface with small (up to 200 m) fluctuations in height and slight slopes.

Plains occupy 64% of the land area. Tectonically, they correspond to more or less stable platforms that have not shown significant activity in recent times, regardless of their age - ancient or young. Most of the land's plains are located on ancient platforms (42%).

Plains are distinguished by absolute and surface height negative-

lying below the level of the World Ocean (Caspian), low-lying- from 0 to 200 m altitude (Amazonian, Black Sea, Indo-Gangetic lowlands, etc.), sublime- from 200 to 500 m (Central Russian, Valdai, Volga uplands, etc.). Plains also include plateau (high plains), which, as a rule, are located above 500 m and are separated from the adjacent plains by ledges (for example, the Great Plains in the USA, etc.). The depth and degree of dissection of them by river valleys, gullies and ravines depends on the height of the plains and plateaus: what

The higher the plain, the more intensely they are dissected.

In terms of appearance, plains can be flat, wavy, hilly, stepped, and in terms of the general slope of the surface - horizontal, inclined, convex, concave.

The different appearance of the plains depends on their origin and internal structure, which largely depend on the direction of neotectonic movements. Based on this feature, all plains can be divided into two types - denudation and accumulative (see diagram 14-A-1-1). Within the former, the processes of denudation of loose material predominate, and within the latter, its accumulation.

The plains on the “shields” of young platforms have a more “restless” hilly topography, with residual elevations such as hills, the formation of which is associated either with lithological features - more

hard stable rocks, or with structural conditions - former convex folds, microhorsts or exposed intrusions. Of course, they are all structurally determined. This is what, for example, the Kazakh small hills and part of the Gobi plains look like.

Plates of ancient and young platforms, experiencing a stable uplift only during the neotectonic stage of development, are composed of layers of sedimentary rocks of great thickness (hundreds of meters and a few kilometers) - limestones, dolomites, sandstones, siltstones, etc. Over millions of years, the sediments hardened, became rocky and acquired stability to erosion. These rocks lie more or less horizontally, as they were once deposited. Uplifts of territories during the neotectonic stage of development stimulated denudation on them, which did not allow young loose rocks to be deposited there. Plains on slabs of ancient and young platforms are called reservoir. From the surface, they are often covered with loose Quaternary continental sediments of low thickness, which practically do not affect their height and orographic features, but determine their appearance due to morphosculpture (East European, southern part of West Siberian, etc.).

During the Pliocene-Quaternary subsidence of territories, even relative ones, sediments carried away from surrounding areas began to accumulate on them. They filled in all the previous surface irregularities. This is how they were formed accumulative plains, composed of loose, Pliocene-Quaternary sediments. These are usually low-lying plains, sometimes even below sea level. According to the conditions of sedimentation, they are divided into marine and continental - alluvial, aeolian, etc. An example of accumulative plains are the Caspian, Black Sea, Kolyma, Yana-Indigirskaya lowlands composed of marine sediments, as well as the Pripyat, Leno-Vilyuiskaya, La Plata, etc. Accumulative plains , as a rule, are confined to syneclises.

We are filled with loose continental sediments: alluvium, proluvium, colluvium, and lake sediments. For example, the Tarim Plain is composed of sands and loess, the Dzungarian Plain is composed of powerful sand accumulations brought from neighboring mountains. The ancient alluvial plain is the Karakum desert, composed of sands brought by rivers from the southern mountains in the pluvial era of the Pleistocene.

The morphostructures of plains usually include ridges These are linearly elongated hills with rounded peaks, usually no more than 500 m high. They are composed of dislocated rocks of different ages. An indispensable feature of a ridge is the presence of a linear orientation, inherited from the structure of the folded region in the place of which the ridge arose, for example, Timansky, Donetsk, Yenisei.

Plains on land form two latitudinal series corresponding to the platforms of Laurasia and Gondwana. Northern Plains Row formed within the framework of the ancient North American and East European platforms, which were relatively stable in recent times, and the young EpiPaleozoic West Siberian platform - a plate that experienced even slight subsidence and is expressed in relief as a predominantly low-lying plain.

The Central Siberian plateau, and in the morpho-structural sense these are high plains - a plateau, was formed on the site of the ancient Siberian platform, activated in recent times due to resonant movements from the east, from the active geosynclinal Western Pacific belt. The so-called Central Siberian Plateau includes volcanic plateaus(Pu-torana and Syverma), tuffaceous plateaus(Central Tunguska), trap plateaus(Tungusskoye, Vilyuiskoye), reservoir plateaus(Priangarskoe, Prilenskoe), etc.

The orographic and structural features of the plains of the northern row are peculiar: beyond the North-

“Plateaus and plateaus are often distinguished only by their appearance and degree of dissection, without taking into account their geological structure. Plateaus are considered less dissected forms of relief and are classified as high plains. Plateaus are usually higher, dissected more intensely and deeper in the marginal parts, so they are classified as mountains.

The Arctic Circle is dominated by low coastal accumulative plains; to the south, along the so-called active 62° parallel, there is a strip of basement hills and even plateaus on the shields of ancient platforms - Laurentian, Baltic, Anabar; in middle latitudes along 50° N. w. - again a strip of stratal and accumulative lowlands - North German, Polish, Polesie, Meshchera, Sredneobskaya, Vilyuiskaya.

On the East European Plain, Yu. A. Meshcheryakov identified another pattern: the alternation of lowlands and hills. Since the movements on the East European Platform were wave-like in nature, and their source in the neotectonic stage was collisions of the Alpine belt, he established several alternating stripes of hills and lowlands, fanning out from the southwest to the east and taking an increasingly meridional direction as they move away from the Carpathians . The Carpathian strip of uplands (Volyn, Podolsk, Prydneprovskaya) is replaced by the Pripyat-Dnieper strip of lowlands (Pripyat, Prydneprovskaya), followed by the Central Russian strip of uplands (Belarusian, Smolensk-Moscow, Central Russian); the latter is successively replaced by the Upper Volga-Don strip of lowlands (Meshchera lowland, Oka-Don plain), then by the Volga upland, Trans-Volga lowland and, finally, by a strip of the Cis-Ural uplands.

In general, the plains of the northern series are inclined to the north, which is consistent with the flow of the rivers.

Southern Plains Row corresponds to the Gond-Van platforms, which have experienced activation in recent times. Therefore, elevations predominate within its boundaries: stratum (in the Sahara) and basement (in southern Africa), as well as plateaus (Arabia, Hindustan). Only within the inherited troughs and syneclises did strata and accumulative plains form (Amazonian and La Plata lowlands, Congo depression, Central Lowland of Australia).

In conclusion, we emphasize once again that mountains and plains, as the main forms of relief on land, are created by internal processes: mountains gravitate towards mobile folded belts

Lands, and plains - to platforms (Table 14). Relatively small, relatively short-lived relief forms created by external exogenous

processes overlap
on large ones and give them a unique appearance. They will be discussed below.

Table 14

Areas of the main types of continental morphostructures (%)