East European platform: landform. Minerals of the East European Platform. Exogenous factors

The East European Plain is part of the East European Platform. This is an ancient and stable block, bordering on the east, the platform is framed by the Urals. The tectonic structure of the East European Plain is such that in the south it is adjacent to the Mediterranean folded belt and the Scythian plate, which occupies the space of Ciscaucasia and Crimea. The border with it runs from the mouth of the Danube, along the Black and Azov Seas.

Tectonics

Older and harder Permian and Carboniferous limestones come to the surface on the banks of the Samarskaya Luka. Strong sandstones should also be distinguished among the deposits. The crystalline foundation of the Volga Upland is lowered to a great depth (about 800 meters).

The closer to the Oka-Don lowland, the more the surface decreases. The Volga slopes are steep and dissected by numerous ravines and gullies. Because of this, a very rugged terrain has formed here.

and the Oka-Don lowland

The common Syrt is another important part of the relief that distinguishes the East European Plain. Photos of this region on the border of Russia and Kazakhstan show an area of chernozem, chestnut soils and solonchaks, prevailing on watersheds and in river valleys. The common Syrt begins in the Trans-Volga region and extends 500 kilometers to the east. It is mainly located in the interfluve of the Big Irgiz and the Small Irgiz, adjoining the Southern Urals in the east.

Between the Volga and Central Russian uplands is the Oka-Don lowland. Its northern part is also known as Meshchera. The northern boundary of the lowland is the Oka. In the south, its natural boundary is the Kalach Upland. An important part of the lowland is the Oksko-Tsninsky shaft. It stretches through Morshansk, Kasimov and Kovrov. In the north, the surface of the Oka-Don lowland was formed from glacial deposits, and in the south, its basis is sands.

Valdai and Northern Uvaly

The vast East European Plain lies between the Atlantic and Arctic oceans. The basins of the rivers flowing into them begin at its highest point - 346 meters. Valdai is located in the Smolensk, Tver and Novgorod regions. It is characterized by hilly, ridge and moraine relief. There are many swamps and lakes (including Seliger and Upper Volga lakes).

The northernmost part of the East European Plain is the Northern Ridges. They occupy the territory of the Komi Republic, Kostroma, Kirov and Vologda regions. The upland, consisting of hills, gradually decreases in a northerly direction until it rests on the White and Barents Seas. Its maximum height is 293 meters. Northern Uvaly is the watershed of the Northern Dvina and Volga basins.

Black Sea lowland

In the southwest, the East European Plain ends with the Black Sea Lowland, located on the territory of Ukraine and Moldova. On the one hand, it is limited by the Danube Delta, and on the other, by the Kalminus River of Azov. The Black Sea lowland consists of Neogene and Paleogene deposits (clays, sands and limestones). They are covered with loams and loess.

The lowland is crossed by the valleys of several rivers: the Dniester, the Southern Bug and the Dnieper. Their banks are characterized by steepness and frequent landslides. There are many estuaries on the sea coast (Dniester, Dnieper, etc.). Another recognizable feature is the abundance of sandbars. The steppe landscape with dark chestnut and chernozem soils prevails in the Black Sea Lowland. This is the richest agricultural granary.

In areas where the rocks of the crystalline basement of the platforms come to the surface, for example, in Ukraine - in the middle reaches of the Dnieper near the cities of Dnepropetrovsk and Krivoy Rog, it is clear that these rocks are crumpled into folds, broken by cracks and have the same structures as in the mountains. From this it was concluded that once, at the first stages of the formation of platforms, mountains existed on the site of modern plains. Then came long periods of quiet tectonic life, during which the mountains were almost completely destroyed by external forces of denudation. Mountain ranges and peaks have been lowered, levelled. An almost plain was formed, which the American geologist and geographer William Davis, one of the founders of the science of geomorphology, proposed to call peneplain (“pen”-almost, “captivity”-plain). The primary ancient peneplains gradually descended and were covered by the waters of the Paleozoic and Mesozoic seas. Thick sediments accumulated at the bottom of the seas. After the receding of the sea and a gentle general uplift of the platform, these sedimentary rocks formed a platform cover.

Simultaneously with the general weak tectonic uplifts and subsidence of the entire platform, its individual sections experienced local (local) movements up or down. It was these movements that formed gentle uplifts and deflections in the surface of the foundation and in the modern relief - those hills and flat depressions that we have already spoken about.

Local movements on the platforms continue to this day. Precise measurements have shown that, for example, the Kursk region is rising by 3.6 mm per year, and Krivoy Rog by 10 mm per year. Seeming to us inviolability and immobility of the surface of our planet is illusory. In fact, movements of different directions and different strengths, caused by processes that have not yet been fully elucidated in the bowels of the Earth, occur continuously throughout the entire history of the planet.

On the plains. where the natural grassy vegetation is destroyed, under the influence of heavy rains or during the rapid melting of snow, jets of water that gather on the slopes wash them away and form deep, fast-growing ravines.

Exogenous forces act on the surface exposed from under the waters of the departed sea - river erosion and accumulation, wind, gravitational shedding, collapse and slumping of collapsing rocks, their dissolution by groundwater. As a result of the interaction of tectonic movements and exogenous processes, a hilly or flat, wavy or hollow relief of the plains was formed. And the stronger the tectonic movements, the more exogenous processes affect them. However, these processes depend not only on tectonic movements. Different parts of the earth's surface receive different amounts of solar heat. Some areas receive a lot of precipitation in the form of rain and snow, while others suffer from drought. Differences in climate also determine differences in the work of exogenous processes.

In humid countries, the main work is done by water. After rains or snow melt, it is partially absorbed into the soil covered with forests and meadows, and partially flows down the slopes. Both soil and surface water are collected in streams, which join into small rivers, and then into large water streams. Rivers flow, eroding their bed, washing away the banks, causing them to collapse and landslide. There is a network of large and small river valleys. Valley relief is a distinctive feature of the geomorphological landscapes of humid regions.

Where ravines are located close to each other, an impassable mixture of sharp and narrow ridges and "small gorges" is formed. Such relief is called badlands or bad lands.

In the forest-steppe and steppe regions, precipitation is less, and it falls very unevenly throughout the year. Rivers and valleys here no longer dissect the surface so densely. But where the natural grassy vegetation is destroyed, during rare but heavy rains or during the spring stormy melting of snow, jets of water that gather on the slopes cut them and form deep, fast-growing ravines.

In arid regions of semi-deserts and deserts, rainfall is very rare. The vegetation here is sparse and does not cover the soil with a protective carpet. The main driving force is the wind. It reigns in deserts everywhere, even in rare riverbeds, which are dry most of the year.

The wind blows dust and grains of sand out of the soil. Black storms carry dust for many hundreds of kilometers. Falling to the ground when the wind subsides, this dust can form thick layers of silty deposits - the so-called loess.

Sand, carried by the wind in the air or rolled over a bare surface, accumulates in deserts, piling up moving dunes, dune chains and ridges. The pattern of the aeolian relief of the sands, which is especially clearly visible on aerial photographs, is determined by the regime and strength of the winds, obstacles encountered in their path - mountain ranges and ridges.

The climate of any region of the Earth did not remain the same. The causes of climate change on our planet are complex and not yet fully understood. Scientists associate these changes with cosmic phenomena, with changes in the position of the Earth's axis and migrations of the poles, with vertical and horizontal displacements of the continents.

Lake Elk. Karelia. Such lakes are located in depressions of the moraine-glacial relief.

The Earth has experienced strong climate fluctuations in recent geological time, especially during the Quaternary period (anthropogen). During this period, large glaciations arose in the polar regions of the globe. In Eurasia, glaciers gradually descended from the mountains of northern Scandinavia, the Urals, and Central Siberia. They connected with each other, formed extensive ice sheets. In Europe, during the maximum glaciation (200-300 thousand years ago), the edge of the ice sheet several hundred meters high reached the northern foothills of the Alps and the Carpathians, descended in tongues along the Dnieper valleys to Dnepropetrovsk and Don to Kalach.

The ice in the ice sheet spread slowly from the center to the edges. On the elevations of the subglacial relief, glaciers ripped off and smoothed rocks, turning large boulders and blocks of rocks. And now, especially in areas close to the centers of former glaciations - in Scandinavia, on the Kola Peninsula, in Karelia, smoothed and scratched, and sometimes polished to a shine granite rocks, the so-called sheep foreheads, are perfectly preserved. According to the location of scratches and strokes on these rocks and glacial boulders, scientists determine the direction of movement of ancient, long-vanished glaciers.

Spotted tundra. This is a flat, dry, clayey tundra with clayey patches the size of a plate or a wheel, usually completely devoid of vegetation. Spots interspersed in dry, vegetated tundra or bordered by a border of plants.

Stones froze into the ice, and it carried them hundreds and thousands of kilometers, piling up along the edges of the ice sheets in the form of ridges and hilly moraines. In the cracks in the glaciers, inside and below them, streams of unfrozen water flowed, saturated with sand, pebbles and gravel. Some cracks were completely clogged with sediment. And when the glaciers began to melt and retreat, sand and gravel masses projected from the cracks onto the surface freed from under the ice. Winding ridges formed. Such sandy ridges up to 30-40 km long and from a few meters to 2-3 km wide are often found in the Baltic States, near Leningrad, in Karelia, Finland. They are called aze- (Swedish for a ridge). Ozes, moraine ridges and hills, as well as kams - rounded sandy mounds and drumlins - hills of a characteristic elongated shape - these are typical witnesses of the relief-forming work of ancient ice sheets that covered vast territories.

Residual glacial moraine, composed of loose loams with accumulations of rock fragments.

Glaciers advanced and retreated several times to the northern regions of Europe, Asia, and North America. During these great Quaternary glaciations, air temperatures decreased throughout the Earth, especially strongly in the polar and temperate latitudes. In the vast expanses of Europe, Siberia and North America, where glaciers did not penetrate, the soil froze to a depth of several hundred meters. Soil permafrost was formed, which has survived to this day in Western and Eastern Siberia, the Far East, Canada, etc. In summer, the surface of the frozen ground thaws, the soil overflows with water, and many small lakes and swamps form. In winter, all this water freezes again. When it freezes, as you know, water expands. The ice contained in the soil breaks them with cracks. The network of these cracks often has a regular lattice (polygonal) pattern. The surface bulges, tubercles are formed. Trees in such areas lean in different directions. When soil ice and permafrost thaw, hollows and depressions form - a thermokarst relief. Permafrost heaving and thawing subsidence destroy buildings, roads, airfields, and people who develop polar permafrost regions have to devote a lot of effort to combat these harmful natural phenomena.

Relief of the East European Plain

Almost the entire length is dominated by a gently sloping plain relief. The East European Plain almost completely coincides with the East European Platform. This circumstance explains its flat relief, as well as the absence or insignificance of manifestations of such natural phenomena as earthquakes and volcanism. Large uplands and lowlands arose as a result of tectonic movements, including along faults. The height of some hills and plateaus reaches 600-1000 meters.

On the territory of the Russian Plain, platform deposits occur almost horizontally, but their thickness in some places exceeds 20 km. Where the folded foundation protrudes to the surface, elevations and ridges are formed (for example, the Donetsk and Timan ridges). On average, the height of the Russian Plain is about 170 meters above sea level. The lowest areas are on the Caspian coast (its level is about 26 meters below the level of the World Ocean).

Relief of the West Siberian Plain

Differentiated subsidence of the West Siberian Plate in the Mesozoic and Cenozoic determined the predominance of accumulation processes of loose deposits within it, the thick cover of which levels the unevenness of the surface of the Hercynian basement. Therefore, the modern West Siberian Plain is characterized by a generally flat surface. However, it cannot be considered as a monotonous lowland, as it was considered until recently. In general, the territory of Western Siberia has a concave shape. Its lowest parts (50-100 m) are located mainly in the central (Kondinskaya and Sredneobskaya lowlands) and northern (Nizhneobskaya, Nadymskaya and Purskaya lowlands) parts of the country. Low (up to 200-250 m) elevations stretch along the western, southern and eastern outskirts: the North Sosvinskaya, Turinskaya, Ishimskaya, Priobskoye and Chulym-Yenisei plateaus, the Ketsko-Tymskaya, Verkhnetazovskaya, Nizhneeniseiskaya. A distinctly pronounced strip of uplands is formed in the inner part of the plain by the Siberian Uvals (average height - 140-150 m), extending from the west from the Ob to the east to the Yenisei, and the Vasyugan Plain parallel to them.

Some orographic elements of the West Siberian Plain correspond to geological structures: gentle anticlinal uplifts correspond, for example, to the Verkhnetazovskaya and Lulimvor uplands, and the Baraba and Kondinsky lowlands are confined to syneclises of the plate basement. However, discordant (inversion) morphostructures are not uncommon in Western Siberia. These include, for example, the Vasyugan Plain, which formed on the site of a gently sloping syneclise, and the Chulym-Yenisei Plateau, located in the basement trough zone.

The West Siberian Plain is usually divided into four large geomorphological regions: 1) marine accumulative plains in the north; 2) glacial and water-glacial plains; 3) near-glacial, mainly lacustrine-alluvial, plains; 4) southern non-glacial plains (Voskresensky, 1962).

The differences in the relief of these areas are explained by the history of their formation in the Quaternary, the nature and intensity of the latest tectonic movements, and zonal differences in modern exogenous processes. In the tundra zone, relief forms are especially widely represented, the formation of which is associated with a harsh climate and the widespread distribution of permafrost. Thermokarst basins, bulgunnyakhs, spotty and polygonal tundras are quite common, and solifluction processes are developed. The southern steppe provinces are characterized by numerous closed basins of suffusion origin, occupied by salt marshes and lakes; the network of river valleys here is not dense, and erosional landforms in the interfluves are rare.

The main elements of the relief of the West Siberian Plain are wide flat interfluves and river valleys. Due to the fact that the interfluve spaces account for a large part of the country's area, they determine the general appearance of the relief of the plain. In many places, the slopes of their surface are insignificant, the runoff of precipitation, especially in the forest-bog zone, is very difficult, and the interfluves are heavily swamped. Large areas are occupied by swamps to the north of the line of the Siberian railway, on the interfluve of the Ob and Irtysh, in the Vasyugan region and the Baraba forest-steppe. However, in some places the relief of the interfluves takes on the character of a wavy or hilly plain. Such areas are especially typical of some northern provinces of the plain, which were subjected to Quaternary glaciations, which left here a heap of stadial and bottom moraines. In the south - in Baraba, on the Ishim and Kulunda plains - the surface is often complicated by numerous low ridges stretching from the northeast to the southwest.

Another important element of the country's relief is the river valleys. All of them were formed in conditions of small slopes of the surface, slow and calm flow of rivers. Due to differences in the intensity and nature of erosion, the appearance of the river valleys of Western Siberia is very diverse. There are also well-developed deep (up to 50-80 m) valleys of large rivers - the Ob, Irtysh and Yenisei - with a steep right bank and a system of low terraces on the left bank. In places, their width is several tens of kilometers, and the Ob valley in the lower reaches even 100-120 km. The valleys of most small rivers are often only deep ditches with poorly defined slopes; during spring floods, water completely fills them and floods even neighboring valley areas.

plan for describing the landform of the East European Plain 1 determine which maps are needed to describe
2 in what part of the mainland is the landform located
3 in which direction it stretches
4 what are the approximate dimensions
5 what is the highest height, the prevailing heights
6 if, find out what is the origin of the relief form under, this is according to the book by the author Korinskaya A V

It is located in the west of Russia from the borders with Ukraine and Belarus to the Urals. The plain is based on an ancient platform, so the relief of this natural area is generally flat. Of great importance in the formation of such a relief were external destructive processes: the activity of wind, water, and a glacier. The average height of the Russian Plain ranges from 100 to 200 m above sea level. The foundation of the Russian platform lies at various depths and comes to the surface only on the Kola Peninsula and in Karelia. Here the Baltic Shield is formed, with which the origin of the Khibiny on the Kola Peninsula is connected. In the rest of the territory, the foundation is covered by a sedimentary cover, different in thickness. The origin of the uplands on the Russian Plain is explained by many reasons: the activity of the glacier, the deflection of the platform, and the uplift of its foundation. The northern part of the plain was covered by an ancient glacier. The Russian plain is located almost entirely within the temperate climate. Only the far north is in the subarctic climate. Continentality on the plain increases towards the east and especially towards the southeast. Precipitation is brought by westerly winds (all year round) from the Atlantic. Compared to other large plains of our country, it receives the largest amount of precipitation. In the zone of maximum moisture are the sources of large rivers of the Russian Plain: the Volga, the Northern Dvina. The north-west of the plain is one of the lake regions of Russia. Along with the large lakes Ladoga, Onega, Chudskoye, Ilmenskoye, there are a lot of small lakes, mainly of glacial origin. In the south of the plain, where cyclones rarely pass, there is less precipitation. In summer, droughts and dry winds often occur. All rivers of the Russian Plain are fed mainly by snow and rain and spring floods. The rivers of the north of the plain are more abundant than those of the south. Groundwater plays a significant role in their nutrition. The southern rivers are shallow, the share of groundwater nutrition in them is sharply reduced. All rivers of the Russian Plain are rich in energy resources. The features of the relief and climate of the Russian Plain cause a clear change in natural zones within its limits from the northwest to the southeast from the tundra to the deserts of the temperate zone. The most complete set of natural zones can be traced here in comparison with other natural regions of the country. The Russian Plain has been inhabited and mastered by man for a long time. 50% of the population of Russia lives here. 40% of hayfields and 12% of Russia's pastures are also located here. In the bowels of the plain there are deposits of iron (KMA, deposits of the Kola Peninsula), coal (Pechora basin), brown coal (Podmoskovny basin), apatites of the Kola Peninsula, potash salts and rock salts, phosphates, oil (Volga-Ural basin). Timber is being harvested in the forests of the Russian Plain. Since forests have been cut down for more than one century, the composition of the forest stand has changed greatly in many central and western regions. Many secondary small-leaved forests appeared. The main areas of the most fertile soils of chernozems are concentrated on the Russian Plain. They are almost completely open. They grow wheat, corn, sunflower, millet and other crops. The areas of arable lands are also large in forest zones. Rye and barley, potatoes and wheat, flax and oats are grown here.

East European Russian Plain Characteristics of the Relief 1) where is the territory located? relief forms are created by this or that process, their placement 7) what natural phenomena are associated with the tectonic and geological structure, with relief features, possible measures to combat them.

The West Siberian Plain stretches from west to east for 1900 km, and from north to south for 2400 km. It is located from the Urals to the Yenisei and from the seas of the Arctic Ocean to the southern borders. The Russian Plain occupies the European part. It is located from the western borders to the Ural Mountains.

2. The Russian plain is confined to the ancient Russian platform, and the West Siberian to the new West Siberian plate. 3. More than 1600 years - Russian platform.

Relief of Russia Relief is a set of irregularities of the earth

4. Russian plain: the lowest point is the Caspian lowland (- 27 meters), the highest is the mountains of the Khibiny (Kola Peninsula).

The average height is 150 meters. The West Siberian Plain - the average height is 120 meters, the maximum is 200 meters. 5. On both plains, river erosion of the plain type is widely represented. Most of the relief of these plains is formed by the action of the rivers.

Aeolian processes are also present on both plains. In the West Siberian Plain, among other things, the permafrost processes, which are widely developed in the north of the plain, are also of great importance. 6. River erosion forms river valleys, consisting of floodplains, terraces, oxbow lakes, riverbanks, etc. Eolian processes formed ancient dune landscapes on the West Siberian Plain (now they are overgrown with forest).

Merlotnye processes form heaving mounds, spotted tundra. Examples: Valdai and Smolensk-Moscow Uplands and Siberian Ridges in Western Siberia. 7. Earthquakes, volcanoes, mudflows, landslides and collapses, tsunamis. Methods of struggle: the use of various instruments for monitoring seismic activity.

Formation of the relief of the plains

Then came long periods of quiet tectonic life, during which the mountains were almost completely destroyed by external forces of denudation. Mountain ranges and peaks have been lowered, levelled. An almost plain was formed, which the American geologist and geographer William Davis, one of the founders of the science of geomorphology, proposed to call peneplain (“pen”-almost, “captivity”-plain).

The primary ancient peneplains gradually descended and were covered by the waters of the Paleozoic and Mesozoic seas. Thick sediments accumulated at the bottom of the seas. After the receding of the sea and a gentle general uplift of the platform, these sedimentary rocks formed a platform cover.

Simultaneously with the general weak tectonic uplifts and subsidence of the entire platform, its individual sections experienced local (local) movements up or down.

It was these movements that formed gentle uplifts and deflections in the surface of the foundation and in the modern relief - those hills and flat depressions that we have already spoken about.

On the plains.

where the natural grassy vegetation is destroyed, under the influence of heavy rains or during the rapid melting of snow, jets of water that gather on the slopes wash them away and form deep, fast-growing ravines.

As a result of the interaction of tectonic movements and exogenous processes, a hilly or flat, wavy or hollow relief of the plains was formed. And the stronger the tectonic movements, the more exogenous processes affect them. However, these processes depend not only on tectonic movements. Different parts of the earth's surface receive different amounts of solar heat. Some areas receive a lot of precipitation in the form of rain and snow, while others suffer from drought. Differences in climate also determine differences in the work of exogenous processes.

In humid countries, the main work is done by water.

After rains or snow melt, it is partially absorbed into the soil covered with forests and meadows, and partially flows down the slopes. Both soil and surface water are collected in streams, which join into small rivers, and then into large water streams. Rivers flow, eroding their bed, washing away the banks, causing them to collapse and landslide.

There is a network of large and small river valleys. Valley relief is a distinctive feature of the geomorphological landscapes of humid regions.

Where ravines are located close to each other, an impassable mixture of sharp and narrow ridges and "small gorges" is formed. Such relief is called badlands or bad lands.

In the forest-steppe and steppe regions, precipitation is less, and it falls very unevenly throughout the year.

Rivers and valleys here no longer dissect the surface so densely. But where the natural grassy vegetation is destroyed, during rare but heavy rains or during the spring stormy melting of snow, jets of water that gather on the slopes cut them and form deep, fast-growing ravines.

In arid regions of semi-deserts and deserts, rainfall is very rare. The vegetation here is sparse and does not cover the soil with a protective carpet.

The main driving force is the wind. It reigns in deserts everywhere, even in rare riverbeds, which are dry most of the year.

The wind blows dust and grains of sand out of the soil. Black storms carry dust for many hundreds of kilometers.

Falling to the ground when the wind subsides, this dust can form thick layers of silty deposits - the so-called loess.

The climate of any region of the Earth did not remain the same.

The causes of climate change on our planet are complex and not yet fully understood. Scientists associate these changes with cosmic phenomena, with changes in the position of the Earth's axis and migrations of the poles, with vertical and horizontal displacements of the continents.

Lake Elk.

Karelia. Such lakes are located in depressions of the moraine-glacial relief.

The Earth has experienced strong climate fluctuations in recent geological time, especially during the Quaternary period (anthropogen).

During this period, large glaciations arose in the polar regions of the globe. In Eurasia, glaciers gradually descended from the mountains of northern Scandinavia, the Urals, and Central Siberia. They connected with each other, formed extensive ice sheets. In Europe, during the maximum glaciation (200-300 thousand years ago), the edge of the ice sheet several hundred meters high reached the northern foothills of the Alps and the Carpathians, descended in tongues along the Dnieper valleys to Dnepropetrovsk and Don to Kalach.

The ice in the ice sheet spread slowly from the center to the edges.

On the elevations of the subglacial relief, glaciers ripped off and smoothed rocks, turning large boulders and blocks of rocks. And now, especially in areas close to the centers of former glaciations - in Scandinavia, on the Kola Peninsula, in Karelia, smoothed and scratched, and sometimes polished to a shine granite rocks, the so-called sheep foreheads, are perfectly preserved.

According to the location of scratches and strokes on these rocks and glacial boulders, scientists determine the direction of movement of ancient, long-vanished glaciers.

Spotted tundra.

This is a flat, dry, clayey tundra with clayey patches the size of a plate or a wheel, usually completely devoid of vegetation.

Spots interspersed in dry, vegetated tundra or bordered by a border of plants.

Winding ridges formed. Such sandy ridges up to 30-40 km long and from a few meters to 2-3 km wide are often found in the Baltic States, near Leningrad, in Karelia, Finland. They are called aze- (Swedish for a ridge).

Help me please…

Ozes, moraine ridges and hills, as well as kams - rounded sandy mounds and drumlins - hills of a characteristic elongated shape - these are typical witnesses of the relief-forming work of ancient ice sheets that covered vast territories.

Residual glacial moraine, composed of loose loams with accumulations of rock fragments.

Glaciers advanced and retreated several times to the northern regions of Europe, Asia, and North America.

During these great Quaternary glaciations, air temperatures decreased throughout the Earth, especially strongly in the polar and temperate latitudes. In the vast expanses of Europe, Siberia and North America, where glaciers did not penetrate, the soil froze to a depth of several hundred meters.

Soil permafrost was formed, which has survived to this day in Western and Eastern Siberia, the Far East, Canada, etc. In summer, the surface of the frozen ground thaws, the soil overflows with water, and many small lakes and swamps form. In winter, all this water freezes again. When it freezes, as you know, water expands. The ice contained in the soil breaks them with cracks. The network of these cracks often has a regular lattice (polygonal) pattern.

The surface bulges, tubercles are formed. Trees in such areas lean in different directions. When soil ice and permafrost thaw, hollows and depressions form - a thermokarst relief. Permafrost heaving and thawing subsidence destroy buildings, roads, airfields, and people who develop polar permafrost regions have to devote a lot of effort to combat these harmful natural phenomena.

Relief of the East European Plain

Almost the entire length is dominated by a gently sloping plain relief.

The East European Plain almost completely coincides with the East European Platform. This circumstance explains its flat relief, as well as the absence or insignificance of manifestations of such natural phenomena as earthquakes and volcanism.

Large uplands and lowlands arose as a result of tectonic movements, including along faults. The height of some hills and plateaus reaches 600-1000 meters.

On the territory of the Russian Plain, platform deposits occur almost horizontally, but their thickness in some places exceeds 20 km.

Where the folded foundation protrudes to the surface, elevations and ridges are formed (for example, the Donetsk and Timan ridges). On average, the height of the Russian Plain is about 170 meters above sea level. The lowest areas are on the Caspian coast (its level is about 26 meters below the level of the World Ocean).

Relief of the West Siberian Plain

Therefore, the modern West Siberian Plain is characterized by a generally flat surface. However, it cannot be considered as a monotonous lowland, as it was considered until recently.

In general, the territory of Western Siberia has a concave shape. Its lowest parts (50-100 m) are located mainly in the central (Kondinskaya and Sredneobskaya lowlands) and northern (Nizhneobskaya, Nadymskaya and Purskaya lowlands) parts of the country.

Low (up to 200-250 m) elevations stretch along the western, southern and eastern outskirts: the North Sosvinskaya, Turinskaya, Ishimskaya, Priobskoye and Chulym-Yenisei plateaus, the Ketsko-Tymskaya, Verkhnetazovskaya, Nizhneeniseiskaya. A distinctly pronounced strip of uplands is formed in the inner part of the plain by the Siberian Uvals (average height - 140-150 m), extending from the west from the Ob to the east to the Yenisei, and the Vasyugan Plain parallel to them.

However, discordant (inversion) morphostructures are not uncommon in Western Siberia. These include, for example, the Vasyugan Plain, which formed on the site of a gently sloping syneclise, and the Chulym-Yenisei Plateau, located in the basement trough zone.

In the tundra zone, relief forms are especially widely represented, the formation of which is associated with a harsh climate and the widespread distribution of permafrost. Thermokarst basins, bulgunnyakhs, spotty and polygonal tundras are quite common, and solifluction processes are developed. The southern steppe provinces are characterized by numerous closed basins of suffusion origin, occupied by salt marshes and lakes; the network of river valleys here is not dense, and erosional landforms in the interfluves are rare.

The main elements of the relief of the West Siberian Plain are wide flat interfluves and river valleys.

Due to the fact that the interfluve spaces account for a large part of the country's area, they determine the general appearance of the relief of the plain. In many places, the slopes of their surface are insignificant, the runoff of precipitation, especially in the forest-bog zone, is very difficult, and the interfluves are heavily swamped. Large areas are occupied by swamps to the north of the line of the Siberian railway, on the interfluve of the Ob and Irtysh, in the Vasyugan region and the Baraba forest-steppe.

However, in some places the relief of the interfluves takes on the character of a wavy or hilly plain. Such areas are especially typical of some northern provinces of the plain, which were subjected to Quaternary glaciations, which left here a heap of stadial and bottom moraines.

In the south - in Baraba, on the Ishim and Kulunda plains - the surface is often complicated by numerous low ridges stretching from the northeast to the southwest.

Another important element of the country's relief is the river valleys.

All of them were formed in conditions of small slopes of the surface, slow and calm flow of rivers. Due to differences in the intensity and nature of erosion, the appearance of the river valleys of Western Siberia is very diverse. There are also well-developed deep (up to 50-80 m) valleys of large rivers - the Ob, Irtysh and Yenisei - with a steep right bank and a system of low terraces on the left bank.

In places, their width is several tens of kilometers, and the Ob valley in the lower reaches even 100-120 km. The valleys of most small rivers are often only deep ditches with poorly defined slopes; during spring floods, water completely fills them and floods even neighboring valley areas.

Please help… Features are given.

"How and why the relief of Russia is changing"

write the reasons for the formation of relief. 3. The plains are bordered by mountains. 4. The east of the country is higher than the west 5. The general decrease in the territory of the country to the north.

Answers:

1) The plains are bordered by mountains. This is always the case when lithospheric plates collide. 2) The East is higher than the West. Russia is divided into 2 parts - East and West. The border is the Yenisei River. The western part is flat, with low hills and hills, and the eastern part is dominated by mountains, although there are also large lowlands. In ancient times, the western part of Russia was the center of glaciation. there are many lakes (Karelia). There are many remains of weathering crusts on the Kola Peninsula. The relief of the East European Plain is late Cenozoic, to the north of Moscow there are moraine ridges, glacial forms. There are reliefs of eolian processes, the formation of dunes. from intermittent and parallel ridges, passes. There are traces of glaciers everywhere. The West Siberian Plain, here the relief is more uniform. Here there are valleys of large rivers, eolian dunes. -East of Russia, the mountains of the North Jurassic changes. The mountains in the East were formed as a result of a geological fault. The largest faults separate the mountains from lowlands. Elevation difference 4500 m.. The youngest mountains, volcanoes in the Kamchatka-Kuril province.

3) Russia, especially in the Asian part, has a slope to the north. Therefore, almost all major rivers flow north

Relief of the East European (Russian) Plain

The East European (Russian) Plain is one of the largest plains in the world in terms of area. Among all the plains of our Motherland, only it goes to two oceans. Russia is located in the central and eastern parts of the plain. It stretches from the coast of the Baltic Sea to the Ural Mountains, from the Barents and White Seas to the Azov and Caspian.

The East European Plain has the highest rural population density, large cities and many small towns and urban-type settlements, and a variety of natural resources. The plain has long been mastered by man.

The substantiation of its definition as a physical-geographical country are the following features: 1) an elevated stratal plain was formed on the plate of the ancient East European platform; 2) Atlantic-continental, predominantly temperate and insufficiently humid climate, formed largely under the influence of the Atlantic and Arctic oceans; 3) natural zones are clearly expressed, the structure of which was greatly influenced by the flat relief and neighboring territories - Central Europe, North and Central Asia. This led to the interpenetration of European and Asian species of plants and animals, as well as to a deviation from the latitudinal position of natural zones in the east to the north.

Relief and geological structure

The East European Uplifted Plain consists of uplands with heights of 200-300 m above sea level and lowlands along which large rivers flow. The average height of the plain is 170 m, and the highest - 479 m - on the Bugulma-Belebeevskaya Upland in the Ural part. The maximum mark of the Timan Ridge is somewhat less (471 m).

According to the features of the orographic pattern within the East European Plain, three bands are clearly distinguished: central, northern and southern. A strip of alternating large uplands and lowlands passes through the central part of the plain: the Central Russian, Volga, Bugulma-Belebeevskaya uplands and the Common Syrt are separated by the Oka-Don lowland and the Low Trans-Volga region, along which the Don and Volga rivers flow, carrying their waters to the south.

To the north of this strip, low plains predominate, on the surface of which smaller hills are scattered here and there in garlands and singly. From the west to the east-northeast, the Smolensk-Moscow, Valdai uplands and Northern Uvaly stretch, replacing each other. The watersheds between the Arctic, Atlantic and internal (endorheic Aral-Caspian) basins mainly pass through them. From Severnye Uvaly the territory goes down to the White and Barents Seas. This part of the Russian Plain A.A. Borzov called the northern slope. Large rivers flow along it - Onega, Northern Dvina, Pechora with numerous high-water tributaries.

The southern part of the East European Plain is occupied by lowlands, of which only the Caspian is located on the territory of Russia.

Figure 1 - Geological profiles across the Russian Plain

The East European Plain has a typical platform relief, which is predetermined by the tectonic features of the platform: the heterogeneity of its structure (the presence of deep faults, ring structures, aulacogens, anteclises, syneclises, and other smaller structures) with unequal manifestations of recent tectonic movements.

Almost all large uplands and lowlands are plains of tectonic origin, while a significant part is inherited from the structure of the crystalline basement. In the process of a long and complex path of development, they were formed as unified in the morphostructural, orographic and genetic aspects of the territory.

At the base of the East European Plain lie the Russian plate with a Precambrian crystalline basement and in the south the northern edge of the Scythian plate with a Paleozoic folded basement. The boundary between the plates in the relief is not expressed. On the uneven surface of the Precambrian basement of the Russian Plate, there are strata of Precambrian (Vendian, in some places Riphean) and Phanerozoic sedimentary rocks with slightly disturbed occurrence. Their thickness is not the same and is due to the unevenness of the basement topography (Fig. 1), which determines the main geostructures of the plate. These include syneclises - areas of deep occurrence of the foundation (Moscow, Pechora, Caspian, Glazov), anteclises - areas of shallow occurrence of the foundation (Voronezh, Volga-Ural), aulacogens - deep tectonic ditches, on the site of which syneclises subsequently arose (Kresttsovsky, Soligalichsky, Moskovsky and others), ledges of the Baikal basement - Timan.

The Moscow syneclise is one of the oldest and most complex internal structures of the Russian plate with a deep crystalline basement. It is based on the Central Russian and Moscow aulacogenes filled with thick Riphean strata, above which the sedimentary cover of the Vendian and Phanerozoic (from Cambrian to Cretaceous) occurs. In the Neogene-Quaternary time, it experienced uneven uplifts and is expressed in the relief by rather large uplands - the Valdai, Smolensk-Moscow and lowlands - the Upper Volga, North Dvina.

The Pechora syneclise is located wedge-shaped in the northeast of the Russian Plate, between the Timan Ridge and the Urals. Its uneven block foundation is lowered to various depths - up to 5000-6000 m in the east. The syneclise is filled with a thick layer of Paleozoic rocks overlain by Meso-Cenozoic deposits. In its northeastern part is the Usinsky (Bolshezemelsky) vault.

In the center of the Russian Plate there are two large anteclises - Voronezh and Volga-Urals, separated by the Pachelma aulacogen. The Voronezh anteclise slopes gently to the north into the Moscow syneclise. The surface of its basement is covered with thin deposits of the Ordovician, Devonian and Carboniferous. Rocks of the Carboniferous, Cretaceous and Paleogene occur on the southern steep slope. The Volga-Ural anteclise consists of large uplifts (arches) and depressions (aulacogens), on the slopes of which flexures are located. The thickness of the sedimentary cover here is at least 800 m within the highest arches (Tokmovsky).

The Caspian marginal syneclise is a vast area of deep (up to 18-20 km) subsidence of the crystalline basement and belongs to the structures of ancient origin, almost on all sides of the syneclise is limited by flexures and faults and has an angular outline. From the west it is framed by the Ergeninskaya and Volgograd flexures, from the north by the flexures of the General Syrt. In places they are complicated by young faults. In the Neogene-Quaternary, further subsidence (up to 500 m) and accumulation of a thick layer of marine and continental deposits took place. These processes are combined with fluctuations in the level of the Caspian Sea.

The southern part of the East European Plain is located on the Scythian epi-Hercynian plate, lying between the southern edge of the Russian plate and the Alpine folded structures of the Caucasus.

The tectonic movements of the Urals and the Caucasus led to some disturbance of the sedimentary deposits of the plates. This is expressed in the form of dome-shaped uplifts, significant along the shafts (Oksko-Tsniksky, Zhigulevsky, Vyatsky, etc.), individual flexural bends of layers, salt domes, which are clearly visible in the modern relief. Ancient and young deep faults, as well as ring structures, determined the block structure of the plates, the direction of river valleys, and the activity of neotectonic movements. The predominant direction of the faults is northwestern.

A brief description of the tectonics of the East European Plain and a comparison of the tectonic map with the hypsometric and neotectonic ones allows us to conclude that the modern relief, which has undergone a long and complex history, is in most cases inherited and dependent on the nature of the ancient structure and manifestations of neotectonic movements.

Neotectonic movements on the East European Plain manifested themselves with different intensity and direction: in most of the territory they are expressed by weak and moderate uplifts, low mobility, and the Caspian and Pechora lowlands experience weak subsidence.

The development of the morphostructure of the north-west of the plain is associated with the movements of the marginal part of the Baltic Shield and the Moscow syneclise; therefore, monoclinal (sloping) layered plains are developed here, expressed in orography in the form of uplands (Valdai, Smolensk-Moscow, Belorusskaya, Northern Uvaly, etc.), and layered plains occupying a lower position (Upper Volga, Meshcherskaya). The central part of the Russian Plain was affected by intense uplifts of the Voronezh and Volga-Ural anteclises, as well as subsidence of neighboring aulacogenes and troughs. These processes contributed to the formation of layer-tier, stepped uplands (Central Russian and Volga) and layered Oka-Don plain. The eastern part developed in connection with the movements of the Urals and the edge of the Russian Plate, therefore, a mosaic of morphostructures is observed here. In the north and south, accumulative lowlands of the marginal syneclises of the plate (Pechora and Caspian) are developed. Interspersed between them are layered-stage uplands (Bugulma-Belebeevskaya, General Syrt), monoclinal-stratified uplands (Verkhnekamskaya) and the intra-platform folded Timan Ridge.

In the Quaternary, the cooling of the climate in the northern hemisphere contributed to the spread of ice sheets. Glaciers had a significant impact on the formation of relief, Quaternary deposits, permafrost, as well as on the change in natural zones - their position, floristic composition, fauna and migration of plants and animals within the East European Plain.

Three glaciations are distinguished on the East European Plain: the Okskoe, the Dnieper with the Moscow stage, and the Valdai. Glaciers and fluvioglacial waters created two types of plains - moraine and outwash. In a wide periglacial (preglacial) zone, permafrost processes dominated for a long time. The relief was especially intensively affected by snowfields during the period of reduction of glaciation.

The moraine of the most ancient glaciation, the Oka, was studied on the Oka, 80 km south of Kaluga. The lower, heavily washed Oka moraine with Karelian crystalline boulders is separated from the overlying Dnieper moraine by typical interglacial deposits. In a number of other sections to the north of this section, under the Dnieper moraine, the Oka moraine was also found.

Obviously, the moraine relief that arose during the Oka Ice Age has not survived to our time, since it was first washed away by the waters of the Dnieper (Middle Pleistocene) glacier, and then it was blocked by its bottom moraine.

The southern boundary of the maximum distribution of the Dnieper ice sheet crossed the Central Russian Upland in the Tula region, then descended along the Don valley to the mouth of the Khopra and Medveditsa, crossed the Volga Upland, then the Volga near the mouth of the Sura River, then went to the upper reaches of the Vyatka and Kama and crossed the Urals in area 60° N In the basin of the Upper Volga (in Chukhloma and Galich), as well as in the basin of the Upper Dnieper, the upper moraine lies above the Dnieper moraine, which is attributed to the Moscow stage of the Dnieper glaciation *.

Before the last Valdai glaciation in the interglacial epoch, the vegetation of the middle belt of the East European Plain had a more thermophilic composition than the modern one. This indicates the complete disappearance of its glaciers in the north. In the interglacial epoch, peat bogs with brazenia flora were deposited in lake basins that arose in the depressions of the moraine relief.

In the north of the East European Plain, a boreal ingression arose in this era, the level of which was 70–80 m higher than the present-day sea level. The sea penetrated along the valleys of the rivers of the Northern Dvina, Mezen, Pechora, creating wide branching bays. Then came the Valdai glaciation. The edge of the Valdai ice sheet was located 60 km north of Minsk and went to the northeast, reaching Nyandoma.

Changes occurred in the climate of the more southern regions due to glaciation. At that time, in the more southern regions of the East European Plain, the remnants of seasonal snow cover and snowfields contributed to the intensive development of nivation, solifluction, and the formation of asymmetric slopes near erosional landforms (ravines, gullies, etc.).

Thus, while ice existed within the limits of the Valdai glaciation, in the periglacial zone, a nival relief and deposits (non-rock loams) were formed. The extra-glacial, southern parts of the plain are covered with thick strata of loess and loess-like loams, synchronous with ice ages. At that time, in connection with the humidification of the climate, which caused glaciation, and also, possibly, with neotectonic movements, marine transgressions occurred in the basin of the Caspian Sea.

Natural processes of the Neogene-Quaternary time and modern climatic conditions on the territory of the East European Plain determined various types of morphosculptures, which are zonal in their distribution: on the coast of the seas of the Arctic Ocean, marine and moraine plains with cryogenic landforms are common. To the south lie the moraine plains, at various stages transformed by erosion and periglacial processes. Along the southern periphery of the Moscow glaciation, there is a strip of outwash plains interrupted by remnant elevated plains covered with loess-like loams, dissected by ravines and gullies. To the south there is a strip of fluvial ancient and modern landforms on uplands and lowlands. On the coast of the Azov and Caspian Seas there are Neogene-Quaternary plains with erosional, depression-subsidence and eolian relief.

The long geological history of the largest geostructure - the ancient platform - predetermined the accumulation of various minerals on the East European Plain. The richest iron ore deposits (Kursk magnetic anomaly) are concentrated in the foundation of the platform. The sedimentary cover of the platform is associated with deposits of coal (the eastern part of the Donbass, the Moscow basin), oil and gas deposits in the Paleozoic and Mesozoic deposits (the Ural-Volga basin), oil shale (near Syzran). Building materials (songs, gravel, clays, limestones) are widespread. Brown ironstones (near Lipetsk), bauxites (near Tikhvin), phosphorites (in a number of regions), and salts (near the Caspian Sea) are also associated with the sedimentary cover.

This physical and geographical country with an area of about 4 million square meters. km. - the largest within Russia. In the geographical literature, the idea of the coincidence of the boundaries of the Russian Plain and the East European Platform has been established. The borders of the latter pass in the west along the line: the south of the Scandinavian Peninsula - the mouth of the Danube - the Perekop Isthmus - the lower reaches of the Seversky Donets - the Volga Delta - Mugodzhary; in the east - along the western foot of the Urals. The territory of the Russian Plain is divided by administrative borders into foreign and Russian parts. We have to study a part of the East European Plain within the borders of the former USSR.

Geological development. This part of the Russian Plain is based on two geostructures of the second rank: the Russian Plate and the Ukrainian Shield. Like the Baltic Shield, they survived the nuclear, protoplatform, and platform–geosynclinal epochs of development (see the corresponding section). In the Phanerozoic, the development of the Russian Plate was very different from the genesis of the shields. Her foundation complex orthogonal and diagonal fault systems was divided into many blocks that experienced differentiated subsidence. Already in the Precambrian, a large number of narrow linearly elongated rift-like structures were laid down along the faults, which were called aulacogenes by N.S Shatsky. In the Riphean, volcanogenic and sedimentary strata began to accumulate on their bottoms. In the Phanerozoic, sedimentation covered the entire area of the geostructure, regardless of the relief of the basement - the cover was forming and the geostructure was turning into a two-story (slab). The processes of transformations of the foundation were also actively continued.

The development of aulacogenes followed two paths: conservation or transformation into syneclises or exagonal depressions (see the corresponding section of the general review). The surface of the basement was flooded by shallow epiplatform seas, at the bottom of which sedimentation was successively going on. The transgressions of the seas have never covered the entire surface of the Russian Plate at the same time. In the early Paleozoic (Cambrian, Ordovician, Silurian), they timidly penetrated to the extreme northwest of the plate, forming sandy-clayey layers (not cemented!) Glint. The Devonian seas covered much larger areas of the northwest (the main Devonian field). Marine and lagoonal facies of the Carboniferous period cover the horseshoe suburbs of Moscow from the northwest and south. Lagoon sediments of the Permian period filled the northeast of the Russian Plate and structures of the Cis-Ural marginal trough (the main Permian field). Thus, the Paleozoic transgressions covered the northern strip of the Russian Plate, successively passing through it from west to east.

In the Mesozoic, the maximum of transgressions shifted to the middle band of the plate. The Triassic lagoonal facies were superimposed on the Permian deposits, protruding especially strongly into the middle zone in the Cis-Ural part of the structure. The Jurassic deposits reflected the further reduction of the lagoons in the middle zone. In the Cretaceous period, marine and lagoonal deposits spread over vast areas, especially in the west of the middle zone. In the Cenozoic, the maximum of transgressions covered the south of the Russian Plate, successively shifting from west to east.

Geotectonic structure . Lower structural floor Russian plate and Ukrainian shield similar to the foundation of the Baltic Shield (see the relevant section). In the composition of the plate, geostructures of the third rank are distinguished: syneclises (Moscow, Baltic, Black Sea), exagonal depressions (Caspian, Pechora), anteclises (Volga–Ural, Voronezh, Belorussian and slopes of neighboring shields close to them - Baltic and Ukrainian). The thickness of the cover within the anteclises is small (the minimum within the Voronezh anteclise is 40 m), in syneclises it reaches 2–3, in exagonal depressions 9–25 km. For the fundamental differences between syneclises and exagonal depressions, see the corresponding section of the general review. On the surface Ukrainian shield there is a thin cover of Paleogene and Neogene deposits, so the basement rocks are exposed only in the valleys of large rivers. structures Timan uplift similar to shields, but they are developed in the folded complexes of the Riphean and were subjected to folding in the Baikal era. The East European Platform makes up a significant part of the Eurasian lithospheric plate, which practically did not experience significant horizontal displacements.

Relief. Orography and hypsometry . The ancient relief of the Russian Plain has not been preserved due to its rapid variability. The modern relief was formed under the influence of the latest tectonics. Uplifts were very weak, weak, rarely moderate. In the Caspian, Pechora, and Black Sea lowlands, weak subsidence was observed. Such a differentiation of the latest movements, with their general low intensity, led to the general spread of plains of different altitudinal levels. In the northern strip of the Russian Plain, lowlands prevail: Pechora and Dvinsko-Mezenskaya (against the general lowland background of which small hills up to 275–300 m high are scattered). They are separated by the Timan and Kanina Kamenya heights, 200–300 m high. In the extreme west, there is a complexly dissected Baltic plain, against the low background of which low (maximum 145–300 m) highlands stand out: Kurzeme, Vidzemskaya, Zhyamaitskaya.

Highlands and lowlands alternate in the middle lane. Along the Northern Ridges, Valdai, Smolensk-Moscow, Belorussian and smaller uplands, the Klin-Dmitrov Ridge runs the watershed of the rivers of the northern and southern directions. Lowland woodlands alternate with them - Vyatsko-Kama, Unzhensko-Vetluzhskoe, Meshcherskoe, Pripyatsko-Dnieper. To the south, meridionally oriented uplands alternate: High Trans-Volga (Common Syrt and Bugulma-Belebeevskaya); Privolzhskaya and Ergeni; Central Russian and Donetsk ridge; Volyn, Dnieper, Podolsk, Kodry and lowlands: Low Trans-Volga, Oka-Don, Pridneprovskaya. At one time, this alternation led to the emergence of the doctrine of the wave-like nature of the relief.

In the south of the Russian Plain, dominance again passes to the low plains (Caspian, Kumo-Manych depression, Black Sea and North Crimean). The highest heights, close to 500 m, reach areas adjacent to the Carpathians, the minimum height is observed on the shores of the Caspian Sea and is 26 m below sea level. The average height of the Russian Plain is estimated at 170 m.

Morphostructure. The morphostructure of stratified plains clearly dominates on the horizontal and subhorizontally occurring layers of the cover of the Russian Plate. In the peripheral areas of the East European Plain, a flat (no more than 3–5 degrees) monoclinal bedding prevails, and alternation of weak and armoring layers is often observed. This leads to the formation of monoclinal-layered plains with a wide distribution of asymmetric ridges - cuestas. Classical are the cuestas of the northwestern part of the Russian Plain. Along the southern coast of the Gulf of Finland and Lake Ladoga, in the Cambrian, Ordovician, and Silurian strata, cuestas were formed, which were called Glint (or the Baltic–Ladoga ledge). Cuestas are also developed within the main Devonian field and in the band of Carboniferous strata.

In the central regions of the Russian Plain, horizontal bedding prevails, in which bedded-denudation uplands have formed (Central Russian, Volga and others). With the alternation of fragile and armoring layers, multi-layered-stratified plains with a stepped relief are formed. Accumulative plains arose within the low plains, the largest of which are the Caspian, Black Sea, Pechora, Oka-Donskaya. On the Dnieper Upland, where crystalline rocks of the basement of the Ukrainian Shield lie under a thin cover, a morphostructure of a semi-buried basement plain was formed. Within the Timan and Donetsk ridges, structural-denudation ridge uplands similar to the socle plains were formed.

Influence of Anthropogenic events on the relief. Pleistocene glaciation . Along with the Alps and North America, the Russian Plain was a kind of testing ground for the study of the Pleistocene. A number of research methods have been proposed, among which stratigraphic and paleontological methods are of particular importance. The stratigraphic method presupposes a detailed study and comparison of Pleistocene geological sections and, above all, moraines, fluvioglacial deposits, and, in the periglacial region, loess and loam. Among the paleontological remains, plant remains play an important role, which are usually divided into two complexes. Complex dryadic flora is typical for glacial. For him, the remains of polar willow and birch, partridge grass or dryad, club mosses, diatoms and other frost-resistant representatives are common. Typical for interglacials brazenieva flora (water lily, yew, hornbeam, fossil hazel, linden, holly, forest grapes).

Okskoye glaciation covered large areas, its southern boundary was located only slightly north of the maximum glaciation boundary. The glacier moved especially a lot of loose, often sandy, material and leveled the surface. Maximum Dnieper the glacier in the southern regions of the Russian Plain had a thickness of no more than 500 - 700 m (in the center -4900 m), since it could not cover the Central Russian Upland. Its far penetration to the south was facilitated by the previous leveling of the surface by the Oka glacier, the relatively “high” temperature of the ice and, as a result, the plasticity and strong watering of the ice. The huge mass of the glacier "pushed through" the earth's crust by about 1 km, and when the ice moved, it created glaciodislocations. At the southern boundary, the pressure of the glacier is greatly weakened, the terminal moraines are thin, but the scale of hydroglacial deposits is significant. During Moscow glaciation, under the influence of the Valdai Upland, the glacier was divided into two large tongues, one of which moved to the south, the other to the southeast. The Valdai glacier developed in a particularly severe climate, so the ice was hard and of low plasticity, the advance of the glacier was minimal, but the exaration was aggravated, the moraine deposits were enriched with boulders, and the forms of the moraine relief were most clearly expressed.

In the Pleistocene periglacial zone, permafrost was widespread. In the era of maximum glaciation, its southern border reached the lower reaches of the Volga, Don and Dnieper. In the Holocene, it quickly degraded over 1–1.5 thousand years. Relic forms of cryogenic relief have been preserved - traces of fissure-polygonal formations, “wedges” of vein ice, thermokarst depressions and others. Aeolian forms were widely distributed, relics of which are found in the modern relief: on the outwash plains of woodlands - sandy formations (dunes, ridges), from the latitude of Moscow to the coasts of the southern seas - a smoothed relief in loess deposits. In the latter, in the Pleistocene, a valley-beam relief was already formed.

Evolution of the Black Sea–Caspian Basin . Under the influence of rhythmic climate changes and tectonic movements, the following transgressions appeared in the south of the Russian Plain (see Table 2).

Table 2. Transgressions of the Black Sea-Caspian basin in the Pleistocene.