Flat plains titles. What are plains

• Lowland is a plain that rises no higher than 200 m above sea level.
• Highlands are flat areas of land with an altitude of 200 to 500 meters above sea level.
• A plateau is a plain with a flat or slightly undulating surface, elevated above sea level by more than 500 meters.

Accumulation

Seabed rise

Change of plains under the influence of water flows

Just like the mountains, the plains gradually change. Much work is done on them by water flows, both permanent (rivers) and temporary, which form on the slopes after heavy rains or during the spring melting of snow.

Each tributary of the river digs out a valley through which it flows, each tributary erodes the banks and deepens, albeit slowly, its bed. The process of erosion occurs especially quickly on hills and plateaus, since the rivers originating from them have a more rapid flow.

Water flowing over the surface washes away the top, arable layer of soil from the fields along with the nutrients that plants need so much. The washout occurs especially quickly on steep slopes not covered with vegetation; that's why steep slopes are not plowed. Slopes with a slight slope should only be plowed across. When plowing a slope transversely, the flowing water is retained by the furrows, absorbed into the ground and does not wash away the soil. Thus, millions of hectares of fertile soil are preserved from erosion. Material from the site

Changing plains under the influence of wind

The winds, sweeping over the plains, do great destructive work. It happens that hurricane-force winds blow over the plains for several days in a row, without ceasing. A dust storm begins. In one such storm, the wind can remove a layer of soil up to 25 cm thick, and previously fertile lands turn into barren wastelands.

Grass strips, which are created at certain intervals in the fields, as well as forest strips, reduce soil blowing.

The wind does especially great work on plains covered with loose sand, not held together by plant roots - dunes and sand dunes. The open expanse of sand is never level.

Main article: Plain

flat plains

If a piece of land has a flat surface, then it is said to be a flat plain (Fig. 64). An example of a flat plain is certain sections of the West Siberian Lowland. There are few flat plains on the globe.

rolling plains

Lowlands

Hills

Plateau

There are plains whose surface is located at an altitude of more than 500 m from ocean level. Such plains are called plateaus. Thus, the vast plain between the Yenisei and Lena rivers is called the Central Siberian Plateau. There are many plateaus in southern Asia, Africa and Australia. Material from the site http://wikiwhat.ru

Plains by external processes

Pictures (photos, drawings)

• Log is high or low

• Which of the Russian plains has the flatter surface?

• The plain is hilly and flat in Russia

• What types of plains are there in appearance?

• Plains below 200 m above sea level

Questions for this article:

Left a reply Ser012005

1. PLAINS - the most common type of relief of the earth's surface. On land, plains occupy about 20% of the area, the most extensive of which are confined to platforms and plates. -All plains are characterized by small variations in elevation and slight slopes (slopes reach 5°). Based on absolute height, the following plains are distinguished:
- lowlands - their absolute height is from 0 to 200 m (Amazonian);
- elevations - from 200 to 500 m above ocean level (Central Russian);
- mountainous, or plateaus - over 500 m above ocean level (Central Siberian Plateau);
- plains lying below ocean level are called depressions (Caspian).

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

and point 3. Based on the origin of the plains, the following types are distinguished:

Marine accumulative (see.

Accumulation). Such, for example, is the West Siberian Lowland with its sedimentary cover of young marine strata;

Continental accumulative. They were formed in the following way: at the foot of the mountains, the products of destruction of rocks carried away 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 by the river (Amazonian);

Abrasion plains (see Abrasion). They arose as a result of the destruction of coastlines by wave action of the sea.

The largest plains in Russia: names, map, borders, climate and photos

These plains arise the faster the weaker the rocks, the more frequent the waves, the stronger the winds;

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 of tectonic movements, cracks and faults appeared in the earth’s crust, along which magma poured onto 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.
(taken from the Internet)

Plains, their classification. Division of plains by absolute height. Landforms associated with continental glaciation.

Plain- this is an area of ​​land or seabed that has a slight fluctuation in heights (up to 200 m) and a slight slope (up to 5º).

They are found at different altitudes, including at the bottom of the oceans. A distinctive feature of the plains is a clear, open horizon line, straight or wavy, depending on the surface topography.

Another feature is that the plains are the main territories inhabited by people.

Since the plains occupy a vast territory, almost all natural zones exist on them. For example, the East European Plain includes tundra, taiga, mixed and deciduous forests, steppes and semi-deserts. Most of the Amazonian lowland is occupied by selvas, and on the plains of Australia there are semi-deserts and savannas.

Types of plains

In geography, plains are divided according to several criteria.

According to absolute height, they are distinguished:

low-lying. The height above sea level does not exceed 200m. A striking example is the West Siberian Plain.

Exalted- with a height difference from 200 to 500 m above sea level. For example, the Central Russian Plain.

Nagornye plains whose level is measured at elevations of over 500 m. For example, the Iranian Plateau.

depressions- the highest point is below sea level.

Example - Caspian lowland.

Separately allocate underwater plains, which include the bottom of basins, shelves and abyssal areas.

By origin, plains are :

Accumulative (sea, river and continental) - formed as a result of the influence of rivers, ebbs and flows. Their surface is covered with alluvial sediments, and in the sea - with marine, river and glacial sediments. Of the sea, we can cite the West Siberian Lowland as an example, and of the river, the Amazon. Among continental plains, marginal lowlands that have a slight slope towards the sea are classified as accumulative plains.

Abrasion- are formed as a result of the impact of surf on land.

In areas where strong winds prevail, rough seas are frequent, and the coastline is formed of weak rocks, this type of plain is more often formed.

Structural- the most complex in origin.

In place of such plains, mountains once rose. As a result of volcanic activity and earthquakes, the mountains were destroyed. The magma flowing from cracks and splits bound the surface of the land like armor, hiding all the unevenness of the relief.

Ozernye- formed on the site of dry lakes.

Such plains are usually small in area and are often bordered by coastal ramparts and ledges. An example of a lake plain is Jalanash and Kegen in Kazakhstan.

3. Based on the type of relief, plains are distinguished:

flat or horizontal– Great Chinese and West Siberian Plains.

wavy- are formed under the influence of water and water-glacial flows.

For example, the Central Russian Upland

hilly- the relief contains individual hills, hills, and ravines. Example - East European Plain.

stepped- are formed under the influence of the internal forces of the Earth.

Example - Central Siberian Plateau

concave- These include the plains of intermountain depressions. For example, the Tsaidam Basin.

Also distinguished ridge and ridge plains. But in nature it is most often found mixed type. For example, the Pribelsky ridge-undulating plain in Bashkortostan.

The land surface was repeatedly subjected to continental glaciation.
During the era of maximum glaciation, glaciers covered more than 30% of the land area.

The main centers of glaciation in Eurasia were on the Scandinavian Peninsula, Novaya Zemlya, the Urals and Taimyr. In North America, the centers of glaciation were the Cordillera, Labrador, and the area west of Hudson Bay (Keewatin Center).
In the relief of the plains the traces of the last glaciation (which ended 10 thousand years ago) are most clearly expressed: Valdaisky- on the Russian Plain, Wurmsky- in the Alps, Wisconsin- in North America.

The moving glacier changed the topography of the underlying surface. The degree of its impact was different and depended on the rocks that made up the surface, on its relief, and on the thickness of the glacier.

The surface, composed of soft rocks, was smoothed by the glacier, destroying sharp protrusions. He destroyed fissured rocks, breaking off and carrying away pieces of them. Freezing into the moving glacier from below, these pieces contributed to the destruction of the surface.

Encountering hills composed of hard rocks along the way, the glacier polished (sometimes to a mirror shine) the slope facing its movement.

Frozen pieces of hard rock left scars, scratches, and created complex glacial shading. The direction of glacier scars can be used to judge the direction of glacier movement. On the opposite slope, the glacier broke out pieces of rock, destroying the slope. As a result, the hills acquired a characteristic streamlined shape "mutton foreheads". Their length varies from several meters to several hundred meters, the height reaches 50 m. Clusters of “ram’s foreheads” form a relief of curly rocks, well expressed, for example, in Karelia, on the Kola Peninsula, in the Caucasus, on the Taimyr Peninsula, and also in Canada and Scotland.
At the edge of the melting glacier it was deposited moraine.

If the end of the glacier, due to melting, was delayed at a certain boundary, and the glacier continued to supply sediments, ridges and numerous hills arose terminal moraines. Moraine ridges on the plain often formed near protrusions of subglacial bedrock relief.

Ridges of terminal moraines reach a length of hundreds of kilometers at a height of up to 70 m. When advancing, the glacier moves in front of itself the terminal moraine and loose sediments deposited by it, creating pressure moraine- wide asymmetrical ridges (steep slope facing the glacier).

Many scientists believe that most terminal moraine ridges were created by glacier pressure.
When a glacier body melts, the moraine contained in it is projected onto the underlying surface, greatly softening its unevenness and creating a relief main moraine. This relief, which is a flat or hilly plain with swamps and lakes, is characteristic of areas of ancient continental glaciation.
In the area of ​​the main moraine you can see drumlins- oblong hills, elongated in the direction of glacier movement.

The slope facing the moving glacier is steep. The length of drumlins ranges from 400 to 1000 m, width - from 150 to 200 m, height - from 10 to 40 m. On the territory of Russia, drumlins exist in Estonia, on the Kola Peninsula, in Karelia and in some other places. They are also found in Ireland and North America.
The flow of water that occurs as the glacier melts washes away and carries away mineral particles, depositing them where the flow rate slows down.

When meltwater deposits accumulate, thick layers of loose sediment, differing from moraine in the sorting of the material.

Landforms created by meltwater flows as a result of erosion, and as a result of sediment accumulation, are very diverse.
Ancient drainage valleys melted glacial waters - wide (from 3 to 25 km) hollows stretching along the edge of the glacier and crossing pre-glacial river valleys and their watersheds.

Deposits from glacial waters filled these depressions. Modern rivers partially use them and often flow in disproportionately wide valleys.
Kama- rounded or oblong hills with flat tops and gentle slopes, externally resembling moraine hills. Their height is 6-12 m (rarely up to 30 m). The depressions between the hills are occupied by swamps and lakes.

Kames are located near the glacier boundary, on its inner side, and usually form groups, creating a characteristic kame relief.
Kamas, unlike moraine hills, are composed of roughly sorted material. The diverse composition of these sediments and the thin clays found especially among them suggest that they accumulated in small lakes that arose on the surface of the glacier.

Ozy- ridges resembling railway embankments. The length of the eskers is measured in tens of kilometers (30-40 km), the width is in tens (less often hundreds) of meters, the height is very different: from 5 to 60 m. The slopes are usually symmetrical and steep (up to 40°).
The eskers extend regardless of the modern terrain, often crossing river valleys, lakes, and watersheds.

Sometimes they branch, forming systems of ridges that can be divided into separate hills. The eskers are composed of diagonally layered and, less commonly, horizontally layered sediments: sand, gravel, and pebbles.
The origin of eskers can be explained by the accumulation of sediments carried by meltwater flows in their channels, as well as in cracks inside the glacier. When the glacier melted, these deposits were projected onto the surface.

Zandra- spaces adjacent to terminal moraines, covered with deposition of meltwater (washed out moraine). At the end of the valley glaciers, the outwash is insignificant in area, composed of medium-sized rubble and poorly rounded pebbles.

At the edge of the ice cover on the plain, they occupy large spaces, forming a wide strip of outwash plains. Outwash plains are composed of extensive flat alluvial fans of subglacial flows, merging and partially overlapping each other.

Landforms created by the wind often appear on the surface of outwash plains.
An example of outwash plains can be the strip of “woodland” on the Russian Plain (Pripyatskaya, Meshcherskaya).
In areas that have experienced glaciation, there is a certain regularity in the distribution of relief, its zoning In the central part of the glaciation region (Baltic Shield, Canadian Shield), where the glacier arose earlier, persisted longer, had the greatest thickness and speed of movement, an erosive glacial relief was formed.

The glacier carried away pre-glacial loose sediments and had a destructive effect on bedrock (crystalline) rocks, the degree of which depended on the nature of the rocks and the pre-glacial relief.

The cover of a thin moraine, which lay on the surface during the retreat of the glacier, did not obscure the features of its relief, but only softened them. The accumulation of moraine in deep depressions reaches 150-200 m, while in neighboring areas with bedrock ledges there is no moraine.
In the peripheral part of the glaciation area, the glacier existed for a shorter time, had less power and slower movement. The latter is explained by a decrease in pressure with distance from the glacier's feeding center and its overload with debris.

In this part, the glacier was mainly unloaded from debris and created accumulative relief forms. Outside the glacier's distribution boundary, directly adjacent to it, there is a zone whose relief features are associated with the erosion and accumulative activity of melted glacial waters.

The plains of our planet

The formation of the relief of this zone was also affected by the cooling effect of the glacier.
As a result of repeated glaciation and the spread of the ice sheet in different glacial epochs, as well as as a result of movements of the edge of the glacier, forms of glacial relief of different origins turned out to be superimposed on each other and greatly changed.

The glacial relief of the surface freed from the glacier was affected by other exogenous factors. The earlier the glaciation, the more, naturally, the processes of erosion and denudation changed the relief. At the southern boundary of maximum glaciation, the morphological features of the glacial relief are absent or very poorly preserved.

Evidence of glaciation are boulders brought by the glacier and locally preserved remains of heavily altered glacial deposits.

The topography of these areas is typically erosive. The river network is well formed, the rivers flow in wide valleys and have a developed longitudinal profile.

To the north of the boundary of the last glaciation, the glacial relief has retained its features and is a disorderly accumulation of hills, ridges, and closed basins, often occupied by shallow lakes. Moraine lakes fill up relatively quickly with sediment, and rivers often drain them. The formation of a river system due to lakes “strung” by the river is typical for areas with glacial topography.

Where the glacier persisted the longest, the glacial topography was changed relatively little. These areas are characterized by a river network that has not yet been fully formed, an undeveloped river profile, and lakes that have not been drained by the rivers.

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Main article: Plain

Plains by structure

Based on their structure, plains are classified into flat and hilly.

flat plains

If a piece of land has a flat surface, then it is said to be a flat plain (Fig. 64). An example of a flat plain is certain sections of the West Siberian Lowland.

There are few flat plains on the globe.

rolling plains

Hilly plains (Fig. 65) are more common than flat ones.

What plains are there in Russia?

From the countries of Eastern Europe to the Urals stretches one of the largest hilly plains on the globe - the Eastern European, or Russian. On this plain you can find hills, ravines, and flat areas.

Plains by height above sea level

Based on absolute height, lowlands, hills and plateaus are distinguished.

In order to determine the absolute height of any part of the earth's surface, an altitude scale is placed on physical maps.

The coloring on a physical map shows at what height from sea level various parts of the earth's surface are located.

Lowlands

If the plain is located no higher than 200 m from ocean level, then it should be called lowland (Fig. 66). The surface of some lowlands is below ocean level. For example, the Caspian lowland is located 26-28 m below sea level, and the Amazon lowland is no higher than 200 m above sea level.

To display the height of plains on a physical map, different colors are used: lowlands should be painted green.

Moreover, the lower the absolute height of this territory, the darker the green color. And the dark green color indicates lowlands below ocean level.

Hills

Those plains that are located at an altitude of more than 200 m from ocean level, but not higher than 500 m, are usually called hills.

Thus, the Central Russian Upland is more than 200 m higher than the level of the Baltic Sea.

Elevations on geographic maps are indicated in yellowish tones.

Plateau

There are plains whose surface is located at an altitude of more than 500 m from ocean level.

Such plains are called plateaus. Thus, the vast plain between the Yenisei and Lena rivers is called the Central Siberian Plateau. There are many plateaus in southern Asia, Africa and Australia.

Material from the site http://wikiwhat.ru

Plateaus are indicated on maps by different shades of brown. The higher the plateau, the darker the color.

Plains by external processes

Based on external processes, accumulation and denudation plains are distinguished. Accumulation plains are formed due to the accumulation and deposition of rocks. Denudation plains, on the contrary, due to the destruction of other relief forms, for example, mountains.

Pictures (photos, drawings)

On this page there is material on the following topics:

• Flat and hilly plains

• What is elevation and examples

• The name of the large plains of Russia is flat and hilly

• What are the names of the plains?

• Flat Plains titles

Questions for this article:

• How do plains differ in altitude above sea level?

Material from the site http://WikiWhat.ru

Main article: Plain

Plains by structure

Based on their structure, plains are classified into flat and hilly.

flat plains

If a piece of land has a flat surface, then it is said to be a flat plain (Fig.

64). An example of a flat plain is certain sections of the West Siberian Lowland. There are few flat plains on the globe.

rolling plains

Hilly plains (Fig. 65) are more common than flat ones. From the countries of Eastern Europe to the Urals stretches one of the largest hilly plains on the globe - the Eastern European, or Russian. On this plain you can find hills, ravines, and flat areas.

Plains by height above sea level

Based on absolute height, lowlands, hills and plateaus are distinguished.

In order to determine the absolute height of any part of the earth's surface, an altitude scale is placed on physical maps.

The coloring on a physical map shows at what height from sea level various parts of the earth's surface are located.

Lowlands

If the plain is located no higher than 200 m from the ocean level, then it should be called a lowland (Fig.

66). The surface of some lowlands is below ocean level. For example, the Caspian lowland is located 26-28 m below sea level, and the Amazon lowland is no higher than 200 m above sea level.

To display the height of plains on a physical map, different colors are used: lowlands should be painted green. Moreover, the lower the absolute height of this territory, the darker the green color. And the dark green color indicates lowlands below ocean level.

Hills

Those plains that are located at an altitude of more than 200 m from ocean level, but not higher than 500 m, are usually called hills.

Plains: characteristics and types

Thus, the Central Russian Upland is more than 200 m higher than the level of the Baltic Sea.

Elevations on geographic maps are indicated in yellowish tones.

Plateau

There are plains whose surface is located at an altitude of more than 500 m from ocean level. Such plains are called plateaus. Thus, the vast plain between the Yenisei and Lena rivers is called the Central Siberian Plateau.

There are many plateaus in southern Asia, Africa and Australia. Material from the site http://wikiwhat.ru

Plateaus are indicated on maps by different shades of brown. The higher the plateau, the darker the color.

Plains by external processes

Based on external processes, accumulation and denudation plains are distinguished.

Accumulation plains are formed due to the accumulation and deposition of rocks. Denudation plains, on the contrary, due to the destruction of other relief forms, for example, mountains.

Pictures (photos, drawings)

On this page there is material on the following topics:

• Names of plains up to more than 500 m

• Types of plains by height

• Lowland and highland size

• They are classified according to height…..

• What is the flattest plain in Russia

Questions for this article:

• How do plains differ in altitude above sea level?

Material from the site http://WikiWhat.ru

Examples of the use of the word plateau in literature.

On the outskirts of the Alashan desert, near the bend of the Yellow River, Ordos was located, a fertile loess plateau, and nearby there existed, replacing each other, the capitals of medieval China - Chang'an, Luoyang, Xi'an and further into the interior of China - Kaifeng.

The Apurimac River, which originates in the highlands plateau in the Andes off the western coast of South America, it is considered by many geographers to be the source of the Amazon.

It gradually dried up, just as the Caspian Sea will dry out over time, thanks to the high concentration of sunlight over vast areas stretching from the Aral Sea to the Pamir Sea plateau.

When the Brass Baboon crossed plateau, Tranto saw him and sounded a greeting.

At the bottom of the slope he saw that the valley turned into a wide rocky plateau- dry, ominous, from which here and there leafless gazan trees of an ancient appearance protruded, having the usual, bizarrely curved shape.

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.

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 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 have virtually no effect on 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-Indigirsk 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 more complex

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.

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 1.

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 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 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

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 (%)

Encyclopedic reference(from the geography textbook for 6th grade “The World of the Earth”)

We live on a planet of the plains. Flat terrain prevails over mountainous terrain both on land and on the ocean floor.

Plains are large and fairly flat areas of the earth's surface. The plains are characterized by slight fluctuations in heights and small slopes.

The largest plain on Earth is Amazonian lowland– located in South America. Its area exceeds 5 million km2. In Russia the largest plain is West Siberian Plain. Its area is about 3 million km2.

Often found on the plains hills– landforms similar to lonely low mountains. In nature, it is quite difficult to distinguish a high hill from a low mountain. Scientists have agreed to call those hills that rise no more than 200 m above the surrounding plain.

In appearance, plains can be flat or hilly. There are no big rises and falls on flat ones.

Vast flat plains are very rare. There are many more small flat plains. They are found along the shores of seas and large rivers.

If the height of the plains does not exceed 200 m above sea level, they are called lowlands. Plains located at altitudes from 200 to 500 m above sea level are called hills, and if above 500 m, they are called plateaus or plateaus. The plateau differs from the plateau in its internal structure and the presence of limiting cliffs - ledges. Many deep gorges run along the cracks on the surface of the plateaus. This gives them the appearance of flat-topped mountains.

Mountains- These are areas of the earth's surface that are sharply raised above the plains. They are characterized by large differences in elevation and significant slopes of the terrain.

However, in the mountains you can find areas of plains. They are usually located in wide depressions between mountain ranges and are called intermountain basins. Extensive mountain systems consisting of mountain ranges and wide, highly elevated intermontane basins are called highlands.

As is known, mountain call any rise with clearly defined slopes, base and peak, which rise above the plain by more than 200 m. The high parts of mountains are called peaks, and the pointed vertices are in peaks. Free-standing mountains are rare, representing either volcanoes or the remains of destroyed mountains. Usually mountains are united in large groups - mountainous countries. For example, Tien Shan, Andes, Caucasus. The mountainous countries stretch up to several thousand kilometers in length.

Mountains are distinguished by height: low, or low mountains,– up to 1000 m, average, or middle mountains, - 1000–2000 m, tall, or highlands,– more than 2000 m.

Structures created by people - houses, quarries, ancient pyramids, dams on rivers, road embankments, canals - show the possibility of human use of underground resources.

Koshevoy V.A., Dushina I.V., Lobzhanidze A.A.. Geography. World of the Earth: textbook. for 6th grade. – M.: Balass, 2005.

The concept of the plain. The word “plain” or the expression “flat place” is well known to everyone. Everyone knows that there are no absolutely flat places, that plains can have a slope, undulations, hills, etc. In geography, the name plains or flat areas mean vast spaces in which the heights of neighboring areas differ relatively little from each other. An example of one of the most perfect vast plains is the West Siberian Lowland and especially its southern part. Here you can drive hundreds of kilometers and not come across a single significant hill. In its northern part, the West Siberian Lowland is more hilly. Nevertheless, here too there are rises reaching 200

m

heights are very rare. But not all flat areas have such a leveled surface. It is enough to point to the East European (or Russian) Plain, within which we have elevations of up to 300 meters or more in absolute height and depressions, the absolute height of which is below ocean level (Caspian Lowland). The same can be said about other large lowlands (Amazonian, Mississippian, Laplata, etc.). The flat regions include not only lowlands, but also many plateaus: Central Siberian, Arabian, Deccan, etc. Due to the high absolute altitude, their surface is usually more dissected by flowing waters. The latter can be clearly seen in the example of the Central Siberian Plateau, within which absolute heights range from 500 to 1 thousand. m,

not counting the valleys of large rivers with absolute altitudes less than 200

m. So far we have talked about large plains. But, in addition to these vast flat areas, there are many smaller plains, located mainly along the banks of rivers, lakes and seas (the lowlands of the Rio, Kurin, Lombard, Rhone, Zeya-Bureya plains and many others).(from 0 to 200 m), high plains, or simply hills(up to 300-500 m), and finally plateaus(over 500 m). Depending on the shape of the relief, plains are classified as flat, inclined, bowl-shaped, wavy, etc. It is important for us to know not only the height and shape of the surface of the plain, but also the origin (genesis) of the plain. The latter is also important because the shape, character and many other features of the plain are determined by its genesis. Therefore, when considering the most typical plains of the globe, we divide them into groups based on genetic principles.

Primary plains. Vast plains emerging from sea level are collectively called primary plains. The primary plains are composed predominantly of horizontally lying strata, which, in fact, determine the basic shape of the surface of these plains. The latter gives grounds to call the primary plains structural. It is also easy to understand that large primary or structural plains are platform areas.

An example of the youngest primary plain is the Caspian Lowland, which became land only at the end of the Quaternary period. The surface of the Caspian lowland is almost not dissected by rivers. The West Siberian Lowland is also a relatively young primary plain, most of which emerged from sea level by the beginning of the Neogene. The surface of this lowland has already been significantly altered by the activity of flowing waters, and in the northern part by the activity of glaciers. Examples of more ancient primary plains are the East European Plain and the Central Siberian Plateau. Many parts of these plains emerged from sea level in Mesozoic and even Paleozoic times. It is clear that these plains have been modified by subsequent processes to a much greater extent. For example, the surface of the Central Siberian Plateau is strongly dissected by rivers, the valleys of which are cut to a depth of 250-300 m. Individual sections of the plateau dissected by rivers, depending on their size, have different names. Thus, large areas with a more or less flat surface and well-defined slopes (at the edges) are called plateau; smaller areas depending on height are called table mountains(Fig. 234) or table heights. The flat upper surface of the mesas here is due to the more resistant rock of the upper strata.

Alluvial plains. Plains formed by sediments and deposits of river waters are collectively called alluvial plains. Among the alluvial plains there are river And deltaic. These plains are described by us in the section “The work of rivers”.

Fluvioglacial plains formed by deposits of loose materials carried by melted glacial waters. They were described by us earlier.

Lake plains. The plains that arose on the site of former lakes are called lake plains. They are flat lake bottoms that have disappeared as a result of rivers draining them or filling lake basins with sediment. The size of such plains is usually small. Using the remains of the former shores of the lake and coastal ramparts, it is possible to reconstruct the outline of the disappeared lakes.

Coastal plains. Along the coasts of the seas, as a result of the work of waves, coastal currents, as well as the work of streams and rivers flowing into the sea, strips of lowlands are formed that border the shores. In some cases, these low-lying plains are the result of the accumulation of sediments carried by coastal water currents, washed in by waves, or deposited by coastal currents. In others, these plains are caused by the abrasive activity of the sea. The sizes of both can be very different. The conditions of origin of these plains are familiar to us.

Lava plateaus. Erupted liquid (basic) lavas can form large, flat spaces called lava plateaus. Lava plateaus are difficult to destroy. Therefore, dense river networks usually do not form here. River valleys are canyon-like in nature and often have steeply falling banks. The latter is also due to the very high strength of the rock. The alternation of lavas and tuffs often gives the shores a stepped character.

The dissection of the lava plateau by canyons is, as it were, the first stage in the transformation of their relief. Subsequently, the valleys expand and the plateau is divided into table shapes.

But even for table forms, the steepness of the slopes always remains characteristic.(peneplains). As a result of long-term destruction of mountains, leveled, slightly hilly surfaces, known collectively as leveled surfaces, or peneplains, can form.

Unlike plains formed by the accumulation of sediments (accumulation), these plains are composed of hard rocks, the occurrence of which can be very diverse. We will talk about the origin of these plains a little later in connection with the transformation of the mountains under the influence of external agents. Upland plateau.

Low-lying areas among mountains are usually a place for the accumulation of those products of destruction that are carried away from the surrounding mountains. As a result, such areas level out and form vast elevated plains called upland plateaus. Examples of such plateaus are the Iranian plateau (about 500 m in height), Gobi (over 1 thousand), Tibet (4-5 thousand m).

All the types of plains we have noted can be combined into three main groups.

The first group is the primary, or structural, plains. The basic shape of these plains is determined by their structure. These are predominantly platform areas.