The Central Russian Upland occupies a central position among the Russian Plain. It stretches from the north-north-west to the south-south-east from the right bank of the Oka valley (Kaluga - Ryazan) to the Donetsk Ridge. From the west and east it is bordered by the Dnieper and Oka-Don lowlands. In the north, it serves as the watershed of the Desna, Oka and Don, to the south it forms the watershed of the Dnieper, Donets and Don.

The central part of the region can be considered the vicinity of the city of Orel, where its higher points are also located. This is the so-called Plavskoe plateau with a height of 310 m, where the rivers Zusha and the Beautiful Mecha originate. The most common heights for the watersheds of the Middle Russian Upland range from 220-250 m. Thus, the Middle Russian Upland rises above the lowest elevations of the Dnieper and Oka-Don lowlands by an average of 120-150 m.

In the southeast, the Don, cutting through the Central Russian Upland, separates from it the Kalach Upland with heights up to 234 m, which serves as the watershed of the Don and Khopra.

The surface of the Central Russian Upland is an undulating plain, dissected by deep valleys of rivers, gullies and branching ravines. The depth of the cut in places reaches 100 and even 150 m. From the Central Russian Upland, such rivers originate as the Oka with its numerous tributaries (Zusha, Upa, Zhizdra), the Don with tributaries Beautiful Sword, Pine, Silent Pine, Kalitva and others, Oskol , Northern Donets, Vorskla, Psel, Seim and a numerous network of smaller rivers and ravines and ravines confined to them.

As already noted in the general part of this work, the main orographic units of the Russian Plain, as a rule, correspond to the main structural units of the Russian Platform.

In this case, we observe the following: in the center of the Central Russian Upland, in the region of Kursk, Orel and Voronezh, crystalline rocks that make up the Voronezh anteclise lie high. Its axial part runs approximately along the line Pavlovsk (on the Don) - Kursk, where the cover of sedimentary rocks does not exceed 150-200 m, and in Pavlovsk, as you know, crystalline rocks are opened by the Don. In all directions from the axis, the sedimentary sequence strongly increases in thickness, and the Precambrian rocks gradually go to a greater depth (Fig. 1). The Voronezh anteclise has an asymmetric structure. Its northern slope is the southern flank of the Moscow syneclise, while the southern slope falls steeply to the Dnieper-Donetsk syneclise.

Rice. 1. Section through the Voronezh anteclise along the Don from Zadonsk to Pavlovsk and further south to Kantemirovka (according to A.D. Arkhangelsky, 1947): 1 - granite; 2 - Devonian (Voronezh, Semiluk and Shchigrov layers); 3 - Devonian (Evlanovsk and Yelets layers): 4 - Carboniferous rocks; 5 - Mesozoic sandy-argillaceous rocks of the ancient Cenomanian; 6 - upper chalk; 7 - Paleogene; 8 - Quaternary deposits

The northern slope of the Voronezh anteclise is covered by Devonian and Carboniferous layers, which are hidden by thin Jurassic and Cretaceous deposits.

The southern slope of the Voronezh anteclise descends very sharply, and with it the Paleozoic rocks that overlap it quickly go to depth, and the terrain is composed of rocks of the Cretaceous and Tertiary ages, which reach considerable thickness here.

On the northern slope of the Voronezh anteclise, the Devonian deposits are represented by dense thick-layered limestones with rare clay interbeds. In the Oka and Don basins, they are exposed by rivers. Near the axis of the Voronezh anteclise, the Devonian layers occur almost horizontally. In the direction of the Moscow syneclise, they detect a fall and increase their power. On the southern slope of the Voronezh massif, the Devonian layers dip steeply towards the Dnieper-Donets syneclise.

Research recent years the extremely turbulent surface of the Devonian was established. This is largely due to the existence on the northern slope of the Voronezh block of the Yelets-Tula and Orlovsky tectonic uplifts, which create the Middle Russian swell of the Russian platform. Within this swell, the absolute marks of the Devonian roof reach 266–270 m, while the absolute marks of the modern surface of the hill are 290–300 m. part of the sea, the sea completely bypassed it. According to B. M. Dan'shin (1936), this uplift significantly influenced the distribution of the Quaternary glacier. It turned out to be the focus that made the glacier of the Dnieper time split into two large languages: the Dnieper and the Don.

In addition to the Central Russian swell, a number of minor uplifts and troughs stand out. These are the Lipitsko-Zybinsk uplift, located in the upper reaches of the Zushi, and the Oka depression, which is used by the upper reaches of the Oka. In addition, in the river basin Zushi discovered Devonian sediments, with which the sustained direction of river valleys is linked. Small anticlines are also found on the river. Ok and elsewhere.

The Carboniferous deposits in the territory under consideration are represented by limestones and a coal-bearing suite lying between them with alternating sand, clays and coal interlayers. In the northern part of the Central Russian Upland, Carboniferous rocks fall unevenly. MS Shvetsov (1932), and then VA Zhukov (1945) point to the existence of sharp folds in the Carboniferous layers, one of which coincides with the Oka valley. In the south, the Carboniferous descends sharply towards the Dnieper-Donetsk syneclise.

The rocks of the Mesozoic (Upper Jurassic and Cretaceous) are mainly represented by sands, as well as writing chalk and marls with occasional clay interlayers. In the center of the Voronezh anteclise, they are insignificantly thick and lie horizontally. In the direction of the Dnieper-Donetsk syneclise, their thickness increases extremely rapidly, and the layers acquire a southwestern slope. In Shchigry, the thickness of the Mesozoic is 52.4 m, in Stary Oskol - 152.2, in Kursk - 225, and in Belgorod - 360 m. On the southern slope of the Voronezh syneclise, in some places there are flexural bends in the Mesozoic layers. They are known near Belgorod, Pavlovsk, but are especially well expressed within the Kalacheka Upland, where folds in the Cretaceous deposits stretch parallel to each other through the cities of Kalach and Boguchar.

Paleogene rocks lying transgressively on Cretaceous rocks are developed only in the southern part of the Central Russian Upland and are mainly represented by sands with rare interlayers of clays, sandstones and marls. They are generally much less thick than the Mesozoic rocks, reaching a maximum of 70 m.

The Central Russian Upland in its northern parts and partly along the western and eastern slopes was covered with a glacier. Therefore, in these areas, we encounter deposits of glacial origin in the form of washed moraine, the thickness of which varies up to 15 m. Typical moraine deposits are noted in a limited number of places, among which we can name the right bank of the Oka between Aleksin and Serpukhov. More often on the Central Russian Upland one can find bands of fluvioglacial sands stretched along river valleys.

The surface formations of the upland are loess-like loams, turning into loess in the south. Their power is variable. On watersheds, it decreases to 2-3 m, while along the slopes of river valleys and gullies it reaches 10-12 m.

Judging by the distribution and thickness of sedimentary deposits that make up the Central Russian Upland, it can be assumed that the Voronezh anteclise intensively influenced geological development territories adjacent to it. Despite the fact that the Central Russian Upland, with its core in the form of the Voronezh ledge of the Precambrian, experienced both positive and negative movements, throughout the entire geological history it was a positive element of the relief, which prevented the spread of the southern seas to the north, and the northern ones to the south. This is evidenced not only by the thickness, but also by the facies composition of the deposits.

Based on this, we can conclude that the Central Russian Upland, as a formation that is quite pronounced geomorphologically, exists at least since the Paleozoic.

The geomorphological peculiarity of the Central Russian Upland lies in its very sharp and young erosional dissection superimposed on ancient erosional forms. The hill is a classic region of development of ravine-beam relief; therefore, the process of its development, as well as of the valley relief, is one of the main issues in the analysis of the elevation relief.

Even S. N. Nikitin (1905) established the ancient erosional nature of the Central Russian Upland, especially ancient along the northern slope of the Voronezh anteclise. On the southern and southwestern slopes, the hydrographic network is younger.

In fact, in the northern regions of the Central Russian Upland, we observe clear traces of a long stage of continental development of the territory, which lasted from the end of the Carboniferous to the beginning of the transgression of the Jurassic Sea. This period left a very uneven surface, the basis of which was the limestones of the Carboniferous and Devonian times. This surface testifies to the intensive erosional and karst processes taking place here. Along with the pre-Jurassic valleys, there are valleys of pre-Cretaceous and, finally, pre-Quaternary ages.

Analyzing the data characterizing the pre-Jurassic, pre-Cretaceous and pre-Quaternary relief of the northern part of the Central Russian Upland, and comparing it with the modern relief, we can conclude that they are close to each other, explained by the fact that the modern hydrographic network in most cases was laid down in ancient, often pre-Jurassic washouts. This applies to the rivers Oka, Proni, Shati, etc.

In the Oka basin, where Cretaceous deposits are also developed, it was found that the valley of the upper Oka, as well as its largest tributaries and the lower reaches of large dens, received clear outlines even before the onset of the deposition of Cretaceous sands, which lined the irregularities of the pre-Cretaceous relief and in many cases smoothed it out. It is very interesting that even the pre-Cretaceous Oka valley had asymmetric slopes.

The modern erosion network of the Central Russian Upland was laid down after the sea finally retreated from this territory, and in the north only after the departure of the glacier. In this regard, the central, most elevated part of the Central Russian Upland, which first entered the continental period of development (Lower Paleogene), has the most ancient hydrographic network; it is followed by the south of the upland (Upper Paleogene). The river network of the north began to form last of all (after the glacier of the Dnieper time left it).

However, studying the history of development and age of the valley-gully network of the Central Russian Upland, one must, in addition, take into account that in the center and north of the upland, where Mesozoic deposits are thin, the ancient pre-Jurassic and pre-Cretaceous network is clearly visible in the modern relief. . Thanks to this, rivers, using it, quickly form their valleys. On the contrary, in the southern part, where the thickness of the Cretaceous and Tertiary deposits is extremely thick, the ancient Upper Paleozoic valley network does not appear in the modern relief and the rivers are forced to make their way in a new place. Because of this, the young rivers of the north have more developed valleys than the rivers of the south that arose at an earlier time.

The development of the hydrographic network of the Central Russian Upland was greatly influenced by the glacier. For the Dnieper glacier, the Central Russian Upland, and in particular the Yelets-Tula and Oryol uplifts, were a serious obstacle to its progress to the south. In this regard, the glacier was able to cover only the northern part of the Central Russian Upland, as well as its western and eastern periphery. The glacier descended in tongues to the south along the rivers Oka, Naruch, Nugra, Zusha and Seim, leaving behind a thin layer of moraine. Accumulative glacial landforms are currently not observed on the Central Russian Upland. The main role of the glacier affected the restructuring of the hydrographic network. There was a damming of the rivers flowing from the hill to the north, east and west. So, for example, B. M. Danshin (1936) believes that there was an overflow of water from the Oka basin to the Desna through the river. Nerussu and R. Navlu. At the same time, according to M. S. Shvetsov (1932), the Oka acquired its latitudinal sections between Kaluga and Aleksin and below Serpukhov.

According to M.S. Shvetsov, in the preglacial period there were two meridional valleys. One is currently used by the upper reaches of the Oka and further in the north of the river. Sukhodrev, the second is used by the meridional section of the river valley. Upy and Okoy from Aleksin to Serpukhov. The damming of the rivers by the glacier, and then by the finite moraine material, forced the rivers to seek their way out to the east and west. As a result of this, latitudinal sections of the river were created. Upa in its lower reaches, Ugry and Oka on the segment between Kaluga and Aleksin, Protva and Oka below Serpukhov.

The view of M. S. Shvetsov, which was firmly established in the literature, was subsequently refuted by V. G. Lebedev (1939), who, in the area of ​​the Oka valley Kaluga - Aleksin, discovered a clearly developed series of ancient alluvial terraces, the heights of which coincide with the heights of the terraces of the pre-Kaluga Oka and the segment, lying below Alexin. Thus, according to V. G. Lebedev, the Oka valley is of the same age, and its morphological differences are explained by various lithological conditions encountered along its path.

Along the western and eastern margins of the Central Russian Upland, at the point of contact with the body of the glacier, a network of valleys of glacial water runoff was traced. P. Ya. Armashevsky wrote about this at one time (1903). He pointed to the existence of a once bypass valley along the edge of the glacier, which received the waters of dammed rivers. The Seim River joined through channels with Psyol and Vorskla. A similar picture was in the east of the Central Russian Upland, where the rivers flowing into the Don Lowland were latitudinally dammed and flowed in the meridional direction along the edge of the glacier to Oskol (Pine, Devitsa, Quiet Pine, Potudan).

After the departure of the glacier, the northern part of the Central Russian Upland, as well as the southern part, was subjected to intense erosional erosion. Due to this, the modern relief of the Central Russian Upland is primarily an erosive relief (Fig. 2). A. I. Spiridonov (1950) writes on this occasion that “its (relief - M. K.) forms are determined by the main pattern, density and depth of the erosion network, as well as the shape of valleys, gullies and ravines.”

Rice. 2. Ravine-gully network of the Central Russian Upland near the city of Belev.

A. F. Guzhevaya (1948) on the Central Russian Upland distinguishes two types of river network pattern: in the north and in the center, where the slope of the initial surface is insignificant and not quite defined, towards the direction of flow surface water influenced by minor slopes of the terrain, the composition of the rocks, and fracturing. In this case, a tree-branching pattern of the river network developed (Zusha, Sosna, Upa, Oka).

A characteristic feature of the hydrographic network of the northern part of the territory, according to A.F. Guzheva, is the narrowness of the valleys, their strong tortuosity and changing asymmetry. Sharp changes in the direction of the rivers are also typical. The slopes of the valley-beam network have a convex shape due to the increase in the steepness of the slope towards the bottom. The upper reaches of the gullies represent narrow gentle hollows, the slopes of which imperceptibly merge with the watershed space.

For the southern and southwestern slopes of the Middle Russian Upland, where the slope of the strata and topographic surface is sharper, the pattern of the river network is simpler; it is poorly developed in width, elongated, according to the slope of the terrain, in the form of a narrow strip (Oskol, Vorskla). Sometimes there are rivers with an asymmetrically developed basin. A. F. Guzhevaya (1948) calls this drawing “flag” (Quiet Pine, Kalitva, etc.). The convex-concave or concave type of slopes prevails here. The steepness of the slope decreases towards the bottom.

The southern and southwestern slopes of the upland are characterized by a pronounced asymmetry of the interfluves. The tops of the beams here are distinguished by a cirque-like structure.

These differences in the direction and pattern of the hydrographic network, according to A. F. Guzheva (1948). are explained by the difference in the original surface on which the river network lay. In the southern and southwestern parts of the Central Russian Upland, there has long been a pronounced slope of the surface to the south and west, as a result of which basins elongated in the same direction were created. In the northern part of the Central Russian Upland, the surface was more even, slightly inclined towards the Moscow Basin, due to which the basin developed evenly, acquiring the pattern of a branching tree.

The density of the division of the Central Russian Upland in its different regions is not the same. According to A. I. Spiridonov (1953), the most dissected region is located to the west of the Oka, where gullies and valleys of the Oka tributaries are widely developed. The density of dissection here is determined by the value of 1.3-1.7 km per 1 sq. km. km. A lower density of dissection is observed on the coast of the Seim, west and north of Kursk, in the south of the upland, in the basins of Psyol, Northern Donets and Oskol, where the density of the valley-gully network is 1.1-1.5 km per 1 sq. km. km. The Zushi and Sosna basins are even less dissected (1.0-1.2 km per 1 sq. km). The central watershed part of the upland is even less dissected (up to 0.8-0.9 km, and in some places further up to 0.3-0.7 km per 1 sq. km). A similar division is observed on the watersheds of the rivers Neruch, Pine, Seim, right tributaries of the Don.

The depth of the incision of the main valleys in different parts of the Central Russian Upland is also not the same. According to S.S. Sobolev (1948), we observe the deepest valleys and ravines within the Kalach Upland in the Oskol basin, where the incision in places reaches 150 m. Oskol, Northern Donets, Psyol and their tributaries. The smallest amplitude of relief fluctuations is observed in the upper reaches of the Oka and Don, where the incision is usually 50-75 m.

Along with the ancient erosional network, the Central Russian Upland is crossed by young erosional forms - ravines and gullies (Fig. 3). It is extremely important to note that modern erosion is confined in the vast majority of cases to the ancient hydrographic network.

Rice. 3. Ravines in Voronezh region(photo 3. 3. Vinogradova)

The morphological appearance of the ravines of the Central Russian Upland depends on the morphology of the gullies that they cut through, on the size of their catchment area, and on the lithological composition of the rocks in which they have to make their way.

A. S. Kozmenko (1937) distinguishes two groups of ravines: bottom and coastal. The first cut through the bottom of the ancient beam, the second its slope. AI Spiridonov (1953) distinguishes between two types of bottom ravines. The ravines of the first type inherit well developed ancient forms of erosion with developed gullet alluvium. The ravines cut into their bottom by 2-3 m and often reach several kilometers in length. Bottom ravines of the second type cut through the bottoms of poorly developed gullies. They are characterized by a steep longitudinal profile, 10 - 15 meters deep and often cut not only into alluvium, but also into bedrock.

Slope or coastal ravines in the Central Russian Upland usually extend for several hundred meters and have a depth of 8 - 25 m. The morphology of these ravines is largely determined by the lithology of the rocks they cut. When alternating loose and hard rocks, they often form a stepped longitudinal profile.

A.F. Guzheva (1948) compiled a map of the ravines of the Central Russian Upland, from which it can be seen that the northern part of the Middle Russian Upland, which belongs to the Oka basin, and the southwestern, located in the Sula and Psyol basins, are characterized by the least development of ravines. This is followed by the southeastern part of the upland within the left bank of the Northern Donets, in its lower reaches, where modern erosion covers only the high, steep right slopes of the valleys of the left tributaries, the basins of the middle reaches of the Psyol and Vorskla. This is followed by the entire central part of the Central Russian Upland, which includes the basin of Zushi, Sosna, Seim, the upper Psyol, where the length of the ravine network per 1 sq. km area ranges from 0.2 to 0.4 km. Finally, the most ravine region is the Donskaya part of the Central Russian Upland and the Kalachevsky Upland. Here the length of the ravine network per 1 square. km area reaches 0.5-1.2 km.

“Modern erosion,” writes A. F. Guzhevaya (1948, p. 63), “which has reached such a large size in this area, is truly a real disaster. Plot of the right slope of the river. The piedmont width of about 3 km is dissected by 25 ravines up to 20 m deep. The ravines of this region are characterized by a strong branching of their peaks. The bottoms of all the beams are cut by ravines.

The Central Russian Upland has all the necessary conditions for the vigorous development of modern erosion processes: 1) a tendency to uplift, 2) the unevenness of the initial relief, 3) the soft composition of surface rocks, 4) the speed of snow cover melting, 5) heavy summer rains, 6) more recent predatory destruction of forests and improper plowing. According to A.F. Guzheva (1948), not just one, but the manifestation in the complex of all these factors explains the wide distribution of ravines within the Central Russian Upland. However, the depth of the erosion base is still one of the most important factors influencing the intensity of development of the ravine network. Black Sea lowland

The position of the characterized territory within the Russian Plain is indicated by the name of the hill. When looking at a geographical map, its middle position on the plain is striking. The Central Russian Upland, stretching from north to south for more than 800 km, and from west to east (at the latitude of the city of Orel) - by 300 km, is a watershed between the Caspian, Black and Seas of Azov. In the north, its border is a wide valley of the river. Oka with upland right bank and vast floodplain meadows on the left bank. In the east, the boundary of the hill can be drawn along the right steep bank of the river. Don, coinciding with the slopes of the hill. From the west, it is bordered by the Dnieper lowland. The southern border runs along the river valley. Seversky Donets. Outside these borders, the Kalach Upland is located, cut off from the Central Russian Valley by the river. Don and located between the lower segments of the valleys of the Bityug and Khopra rivers.

The Central Russian Upland is a wavy plateau, strongly indented by deep valleys of rivers, beams and ravines, lying above sea level above the isohypse of 200 m. Its most elevated part is located between Kursk and Efremov, where individual points of the relief have heights of 290-300 m.

At the heart of the Central Russian Upland (the region of Kursk, Voronezh and Orel) is the Voronezh anteclise, composed of Precambrian rocks that lie shallow here. The Kursk magnetic anomaly, which was discovered using gravimetric and magnetometric methods, is confined to Precambrian rocks. A band of magnetic anomalies is observed along the Kursk-Tim-Schigry line. The deposit is represented by quartzites, the average percentage of iron content in them is 35-45. This deposit, discovered in the center of the European part of the USSR, is of great importance for the development of industry. The thickness of sedimentary deposits overlying bedrock does not exceed 120-200 m. To the sides of the anteclise axis (Pavlovsk-Kursk), Precambrian rocks go to a greater depth, and the thickness of sedimentary deposits increases accordingly.

In the north (on the gentle slope of the Voronezh anteclise), the most ancient deposits are Devonian, represented by limestones, sandstones, clays, which are part of the "Central Devonian field". They are opened by rivers in the Don and Oka basins, where they form picturesque valleys. In the southern part of the region (on the steep southern slope of the Voronezh anteclise), the Devonian layers dip steeply towards the Dnieper. In the area of ​​Kaluga and Tula, the Devonian deposits are overlain by Carboniferous deposits, which stretch across the upland in a wide strip in the direction from west-north-west to east-south-east. Carboniferous deposits are mainly represented by limestones, among which lies the productive clay-coal-bearing stratum of the Moscow Basin, which belongs to the Lower Carboniferous. It is associated with deposits of brown coal, the development center of which is located in the region of Novomoskovsk, as well as iron ores, which are used by the Lipetsk Metallurgical Plant. Ores occur in the Tula region. In the south, Carboniferous deposits plunge sharply towards the Dnieper-Donetsk syneclise.

There are no Permian and Triassic deposits on the Central Russian Upland. Jurassic and Cretaceous deposits are not distributed everywhere, but occupy mainly the eastern, southern and western regions, as well as partially the central ones. Jurassic deposits are represented by clays with siderites and continental sandy-clayey rocks. They come to the surface in few places, as they are covered with Cretaceous deposits, the thickness of which consists mainly of various sandy rocks with rare interlayers of clays and phosphorites. In some places, the Cretaceous stratum is thicker and breaks up into two sections. The upper section ends in the southwest with layers of white writing chalk, which is mined in the Belgorod region. Deposits of white writing chalk form picturesque rocks. Due to the erosion of the chalk, high pillars are formed, called "divas" (near Belgorod, Divnogorie). Cretaceous sands and loess-like loams, which cover the layers of writing chalk, are very loose. Deep ravines with vertical walls are developed in loess-like loams. Towards the Dnieper-Donetsk syneclise, the thickness of the Mesozoic rocks increases, reaching 360 m in Belgorod; their power in Shchigry is 52 m. In the Tertiary, the entire northern part of the upland from the Voronezh-Kursk line was dry land. To the south of this line, sandy rocks belonging to the lower stages of the Paleogene are developed.

In the Quaternary, the glacier entered the Central Russian Upland only along its outskirts, covering the northern part, as well as partially western and eastern slopes. Within these territories, deposits of glacial origin are represented by washed-out moraine, which can be observed in the valley of the river. Oka near the town of Chekalina (Likhvin). Here, bands of fluvioglacial sands are widespread in large numbers, which are extended along river valleys. Quaternary deposits are mainly represented by brown carbonate loess-like loams, as well as reddish-brown clays, loams and sandy loams of deluvial-eluvial formation. Loess-like loams in the south turn into loess. Their power is different. On watersheds, loesses are often completely absent or reach 2-3 m. On the slopes of river valleys and gullies, their thickness is 10-12 m. Lithology has a great influence on the formation of the relief of various parts of the upland and introduces significant differences into it.

The northern part of the upland up to the parallel of Orel, where limestones are widely represented, is sharply dissected by deep river valleys. On the slopes of the valleys, solid layers of limestone form steep and rocky walls, cornices, cliffs, underlying the overlying loose strata, which are often represented by loess-like loams. Limestones contribute to the creation of small canyon-like valleys. The development of karst forms is also connected with them. In the middle and southern parts of the territory, where loose strata are developed, wide terraced valleys with sloping slopes predominate. Sharper landforms are confined to areas where writing chalk is distributed. Such a roughly dissected relief with a large amplitude of relative heights is observed near Belgorod. In the loess layer, ravines with steep walls arose.

The modern relief of the Central Russian Upland was created mainly by the eroding activity of water flows, which was closely related to the epeirogenic movements of the earth's crust, lithology, climatic factors, etc. M. V. Karandeeva writes that the geomorphological originality of the Central Russian Upland lies in its very sharp and young erosional dismemberment superimposed on ancient erosion forms.

The hill is a classic region of development of ravine-beam relief. Numerous river valleys, as well as a dense network of ravines and gullies, give the surface a rugged character. In different regions of the Central Russian Upland, the density of dissection is not the same. The most dissected region is the northern one - to the west of the Oka, less - the southern one, in the basins of the Seversky Donets, Oskol, Psel, etc., as well as the central watershed part. Particularly deep valleys and ravines are located within the Kalach Upland and in the southern parts of the Central Russian Upland, where the incision depth reaches 125-150 m. Here the ravine-beam network reaches significant development - 1-2 km ravines account for 1 km 2 area.

Ravines are a characteristic feature of the Central Russian Upland as a whole. The riverine sections of the interfluves are heavily indented by ravines, and only some of them go far into the watersheds. There are known cases of sawing of watersheds by ravines. The gully network reaches its greatest development in the basin of the Oka and Truda rivers (the left tributary of the Sosna river) and in the basin of the upper reaches of the Kroma, Nerucha, Svana, and other rivers. climatic conditions(rapid melting of snow in spring, the occurrence of frost cracks and showers). Favorable for the growth of ravines natural conditions in the past, they were intensified by human economic activity, by primitive agriculture, devoid of elementary agricultural technology. The lack of land of the peasants in pre-revolutionary Russia led to the fact that the steep slopes of valleys and gullies, i.e., the most dangerous areas in terms of erosion, were plowed up. The ravine originated in loose soil, then, growing, it turned into a narrow, branching deep rut.

Interfluves are flat or slightly undulating areas, rising above sea level by an average of 250 m. The slopes of the watersheds are gently sloping, they noticeably decrease towards the river valleys and are usually dissected by ravines. On the surface of the watershed spaces, depressions (steppe saucers) with a diameter of 15-20 and 50 m and depth 1.5-2m.

The river network of the Central Russian Upland is dense; it divides its surface in various directions. Within the upland, many rivers of the Russian Plain begin and flow. This is where the river starts. Oka with tributaries Upa, Ugra, Zusha, Zhizdra and Protva. The river flows in the western part. Desna, in the southwestern part, the rivers Seim, Psel, Vorskla begin, flowing into the river. Dnieper. Rivers start in the south Seversky Donets and Oskol. Somewhat east of Lake Ivan, in the upper reaches of a shallow ravine, at the bottom of which a strip of marshy soil with puddles of water meanders, the river originates. Don. The Don River to the mouth of the river. The Bityuga flows in a meridional direction, and then it turns east and comes close to the Volga.

Climate. The climate of the Central Russian Upland and the Oka-Don Lowland lying to the east of it is formed under the influence of two factors: 1) cyclonic activity and the associated entry of air masses of various origins (both warm from the west and southwest, and cold, arctic); 2) heating or cooling the incoming air, depending on the state of the underlying surface and the radiation entering the Earth's surface.

The described area is characterized by moderately cold winters, moderate summers and sufficient moisture. The continentality of the climate increases towards the east and southeast. The radiation balance for the year is 27-32 kcal / cm 2. The amount of incoming solar radiation for the summer months reaches 41-44kcal / cm 2.

Due to the large role of the Atlantic occurrences, the isotherms of the winter months, as in other regions of the Russian Plain, deviate from the parallels and are located from the northwest to the southeast. The average temperature in January fluctuates in different parts from -9 to -12°, the absolute minimum is -35, -40°. Such temperatures are observed during the stagnation of air masses and their cooling.

The maximum height of snow cover is observed in the third decade of February; it starts to decrease from 45 cm in the northeastern regions up to 30 cm in the southern and southwestern ones, which is explained both by the influence of thaws and by a reduction in the total duration of snow cover. There are often snowstorms in February.

During the summer period, usually in the second half of summer, the weather can be overcast and rainy due to the passage of cyclones or hot and dry with intermittent showers and thunderstorms. The latter is observed during the transformation of air masses in vast anticyclones, which occupy most of the European territory of the USSR.

In summer, the highest temperatures are observed in the southeastern part of the region (the average July temperature in Voronezh is +21°C), slightly lower than the temperature in the northwestern part (up to +19°C). The maximum precipitation falls in July (60-70 mm). The annual amount of precipitation brought by both western and southern cyclones on the territory of the described region is on average 500-550 mm, decreasing slightly to the southeast.

Soils. In the forest-steppe part of the Central Russian Upland, there are two soil bands: a band of gray forest-steppe soils and a band of leached and degraded chernozems. The border between them runs along the line: Kursk-Orel-Mtsensk-Odoev-Tula-Mikhailov.

In the steppe zone, there are: a strip of typical chernozem and a strip of medium-humus ordinary chernozems.

The soils of the forest-steppe and steppe zones are characterized by a high content of humus. In the poorest varieties of forest-steppe soils (in podzolized forest-steppe soils), the percentage of humus content is at least 2.5, in chernozems it reaches 10 or more. Developed on loess or loess-like loam, these soils have a good mechanical composition capable of producing a granular structure that provides favorable conditions for plant development. These soils are easily cultivated.

Vegetation. At present, most of the territory of the upland has been plowed up and natural vegetation has been preserved mainly along river valleys, as well as along the slopes of gullies and ravines. As a result of predatory deforestation in pre-revolutionary times, only small areas (Tula Zasek) remained of the former forests. They give an idea of ​​the forests of the past. The tree stand in the acres consists of oak( Quercus robur) with his usual companions - ash( Fraxinus excelsiot), maple ( Acer platanoides), linden ( Tilia cordata). In addition to oak forests, there are birch and aspen groves.

AT northern parts In the Central Russian Upland, on steep limestone slopes, upland birch forests are developed. Relicts are found in the grass cover: silky wormwood, lupine clover, etc.

In the typical forest-steppe subzone, modern forests are represented by ravine oak forests, which have survived to this day only in a few places and in small areas (the region of Belgorod and Valuyek). In the south of the upland, within the limits of the exit to the surface of chalk deposits, chalk forests are developed, which have also been preserved in a few places (the right bank of the Nezhegol River, the Oskol region, the right bank of the Potudan River, etc.). Of great interest is the vegetation in the Galichya Gora region (Lipetsk region), where there is an accumulation of relict plants, of which there are a large number here. Among them: fern, steppe kostenets, kuzmicheva grass, Sophia's wolfberry, shaggy breakwort, etc. Aspen-oak bushes are developed along the depressions of the region's interfluves.

The steppe areas of the forest-steppe are almost completely plowed up, and spots of the virgin steppe have survived only in a few places, such as the Streletskaya steppe, the Cossack and Yamskaya steppes (they are part of the V.V. Alekhin reserve). These spots belong to mixed grass steppes with large quantity plants. Here, among the cereals, a direct fire stands out ( Bromus erectus) and dog bent( Agrostis canina), and from sedges - low sedge( Carex humilis) and etc.

The southeastern part of the Central Russian Upland, together with the Kalach Upland, was occupied by steppes before plowing.

The animal world, as well as vegetation, changes in the direction from northwest to southeast. Even 200-300 years ago, the north of the Central Russian Upland was inhabited by a large number of animals, which were representatives of both forest and steppe fauna. Bears, elks, deer, roes lived in the forests, ground squirrels, jerboas, and bobaks were found in the steppe areas. In order to restore the fauna in the Voronezh State Reserve, beavers are currently bred.

The fertile soils of the Central Russian Upland, a large number of minerals contribute to the development of agriculture and industry associated with local raw materials. A lot of sugar, bread, phosphorite flour and local building materials are produced here. In addition, the metalworking and machine-building industries are developed.

- Source-

Davydova, M.I. Physical geography of the USSR / M.I. Davydova [and d.b.]. - M .: Education, 1966. - 847 p.

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The relief of Russia is amazingly diverse. On its territory there are large mountain systems, vast lowlands, rocky plateaus and highlands. In the south-west of the European part of the country, Central Russian is located. It is about this form of relief that we will describe in detail in our article.

Central Russian Plain: description and geographical location

The Central Russian Plain stretches from north to south for almost a thousand kilometers, from the Oka River valley to the slopes of the Donetsk Ridge. In the west it is limited by the Polessky lowland, and in the east by the Oka-Don plain. In the southwest, it smoothly passes into the Dnieper lowland. The absolute heights of the area are gradually decreasing in the southern and south-western directions from 260 to 190 meters. The highest point is 303 meters above sea level.

About seven million people live within the Central Russian Plain (of which 35% live in villages and villages). The main cities of the region: Belgorod, Tula, Bryansk, Yelets, Lipetsk, Stary Oskol, Kharkiv, Sumy, Glukhov.

So, where is the Central Russian Plain, we have already found out. Now let's take a closer look at the features geological structure and relief of this morphostructure.

General geology and minerals

As already mentioned, the plain is based on crystalline rocks of the ancient Precambrian basement (or the so-called Voronezh massif). From above, they are covered with a layer of sedimentary rocks that is insignificant in thickness - limestone, chalk, sandstone and clay.

The northern parts, western and partially eastern slopes of the plain were previously covered by a glacier. In this regard, in these territories today one can see numerous deposits of glacial origin - moraines, the thickness of which in some places reaches 15 meters. Classical moraine deposits are found on the right bank of the Oka, in the section between Serpukhov and Aleksin.

The Central Russian plain is rich primarily in iron and the largest in terms of its reserves is the Mikhailovskoye iron ore deposit. In addition, significant deposits of limestone, brown coal, granite and other building materials are concentrated in the bowels of the region.

The Central Russian Plain: Key Features of the Relief

In this area, nature has created all the necessary conditions for the active formation and development of water-erosion processes and landforms:

• Elevated area.
• Significant differences in absolute heights.
• Relatively soft rocks.
• Heavy and heavy rainfall in summer.
• Low percentage of forests.

As a result, classical ravine-gully-valley landscapes have formed and continue to form in the region. At the same time, water erosion is rapidly reducing the area of ​​land suitable for agriculture every year. The depth of dissection of the earth's surface on the plain in places reaches 100-120 meters.

Within the Central Russian Upland, suffusion (steppe saucers and funnels), gravitational (cliffs, landslides), eolian (small sand dunes) landforms are also common. On the Ukrainian part of the plain (in particular, in the Sumy region) there is karst. In the general relief of the uplands, the right banks of the rivers, as well as the areas and tracts of Belogorye, Krivoborye, Galichya Gora, which we will discuss later, are noticeably distinguished by their more picturesque appearance.

Hydrography, flora and soils of the region

The climate of the Central Russian Plain is temperate continental. Summers are moderately hot, and winters are frosty and quite snowy. The average annual precipitation ranges from 400 to 650 mm. The hydrographic network is well developed. The largest rivers of the region: Desna, Seim, Psel, Don, Vorskla, Oskol, Ugra, Zhizdra, Zusha, Seim. Within the plain is the source of the Oka - one of the main tributaries of the Volga.

The soil cover of the upland is represented mainly by chernozems and gray forest soils (in the north). Soddy-podzolic soils are widespread under large forest tracts, and in river valleys - ray-chernozem, marsh and sandy soils. Most of the territory of the plain is today plowed up.

About 80% of the area of ​​the Central Russian Upland is located in the natural forest-steppe zone. Significant areas are also occupied by swamps. In the forests, the main tree species are oak, pine and birch. Less common are maple, linden and ash. Willow and alder groves grow along the banks of rivers and streams.

Nature Reserve "Belogorye"

The reserve with the beautiful name "Belogorye" covers an area of ​​2 thousand hectares in Belgorod region. Under the special attention of scientists there is an old oak forest, whose age is at least 300 years. For several centuries in a row it was the private hunting property of the Sheremetevs, and therefore it has been perfectly preserved. Another unique corner of the reserve is the so-called Yamskaya steppe. This is exactly what the reference meadow steppe of Central Russia looks like. The botanical diversity of this area is simply amazing: one square meter There are about 80 species of plants in the territory!

In general, there are 370 species of plants, 150 species of birds and 50 species of various mammals within the boundaries of Belogorye.

Tract Krivoborye

Krivoborye is an amazing corner of the Russian forest-steppe. It is located in the Ramonsky district of the Voronezh region. The tract is a steep right slope of the Don, overgrown with sparse forest and shrubs. The height of the coastal cliff reaches 50 meters, and the steepness of the slope is 75 degrees. The river bed in this place also deserves attention: here it is very winding and complicated by numerous rifts.

The Krivoborye tract was included in the list of geological natural monuments back in 1969. Its total area is 15 hectares.

Reserve "Galichya Gora"

Galichya Mountain is the tiniest reserve on the planet, its area is only 19 hectares. It is located in the Lipetsk region. At the same time, in such a small area, great amount unique natural landscapes and objects. Within the limits of the reserve, plant species grow that are completely uncharacteristic of the rest of the Central Russian Plain. And this main riddle Galich Mountain, over which scientists have been fighting since 1925. It was then that the reserve was founded.

The main attraction of the Galichya Mountain is a picturesque rocky hill located on the high right bank of the Don. It is composed of Devonian limestones. Outcrops of these rocks "sheltered" about 650 species of plants on their cliffs. An impressive figure - botanists at the local museum of nature will tell you. Here you can learn about all the diversity and uniqueness of the natural landscapes of this reserve.

Central Russian Upland, Kalach Upland and Oka-Don Lowland. Lesson objectives: Create an image of the Central Russian Upland, the Kalach Upland and the Oka-Don Lowland; show their uniqueness and specificity. To develop speech activity, the ability to independently obtain knowledge from various sources of information.

To cultivate patriotism, a sense of beauty, love for nature.

Equipment: physical and geographical map of the Voronezh region, tectonic map of Russia, physical and geographical map of Russia, atlas of the Voronezh region.

Note: the students were given advanced tasks to prepare a report about the "Small" and "Big" divas.

During the classes

Teacher. It seemed, creating the Earth, the Gods

The plains were not taken seriously ...

All day, just a feeling of anxiety

Space reflecting the stars...

But, at night, filled with silence,

Comes, suddenly, a sudden guess.

The whole world is inside, because it is always with you

Plain, just a clean notebook,

Ready for your story.

Shamefully covers the body with dust

And frowns from someone else's attention

Alien worlds, they were different,

In hope, in faith, in fear, in anticipation...

There is an energy of birth in the void,

Temporarily imprisoned in peace

Like a cradle of holy inspiration...

The plain sleeps, weary of the heat.

Teacher. Each physical and geographical country is unique and unrepeatable. Today we have to travel to all these countries. In this lesson, we are going with you on an interesting journey through the Central Russian Upland, the Kalach Upland and the Oka-Don Lowland.

These landforms have come a long way in development, and the features of their surface largely depend on the geological structure, tectonic regime and relief formation processes in the past and present.

Both internal (endogenous) and external (exogenous) forces take part in the development of the relief of any territory. The development of the relief depends on their ratio. Endogenous forces create large surface irregularities (positive and negative), and external forces tend to level them: smooth out positive ones, fill negative ones with precipitation.

We are expected to get acquainted with the history of formation, tectonic structure and topography of the study area. To do this, you will be divided into three groups, each of which will analyze a certain form of relief and fill in the table.

Teacher. Using the text of the textbook pp. 16-22 and maps of the atlas of the Voronezh region:

Group 1 - analyzes the Central Russian Upland.

It is located on the right bank of the Don River and stretches from the northern to the southern borders of the region. The Central Russian Upland began to separate from the surrounding territories as a result of tectonic movements of the Neogene and Quaternary periods, that is, 25 million years ago. During this time, the rise was about 250 meters. In some places, even today it is from 2 to 4 mm per year, which contributes to increased erosional dissection - the growth of ravines and gullies. Ravines and gullies here usually have convex and steep slopes. They are deep. River valleys, gullies, ravines and watershed spaces separated between them, along with various kinds of remnants, divas, korvezhki ( Korvezhka- The local name (south of the Central Russian Upland) of low, regular rounded chalk remnants not completely separated from the river or ravine slope (Milkov, 1970) form a large group of erosive landforms created by the activity of flowing waters.

From the east, the Central Russian Upland breaks off to the Don in a rather steep and high ledge. The high banks of the Don, built of chalk and marl, form a kind of white mountain range that stretches from the village of Gremyache to the southern border of the region. In some places they meet high, in the form of towers, chalk remnants - divas that can form groups - Large and Small divas near the Divnogorsky farm and in the Divnogorskaya beam.

Along the coast of the Don, Potudan, Black Kalitva and Quiet Pine, there are domed remnants and semi-remnants - korvezhki. As a result of erosion, they separated from the watersheds. The relative height of some of them can reach 30 m.

Landforms of non-erosion origin are less common. These are karst, landslide, suffusion and anthropogenic landforms.

Group 2 - analyzes the Kalach Upland;

Kalach Upland It is located in the southern part of the region, bounded by the Don valley, the northern border runs along the line Liski - Talovaya - Novokhopersk. The hill was formed as a result of the Kalach tectonic uplift. Just as on the Central Russian Upland, the main relief-forming rocks are chalk-marl strata of Cretaceous age. However, there are some peculiarities here. For example, chalk-marl deposits on watersheds are overlain by later deposits of Neogene and Quaternary sediments. This creates conditions for the formation of landslides.

The similarity of the Kalach Upland with the Central Russian is that significant absolute heights (up to 234 m) lead to a strong ravine-gully division between the Don and Khopra rivers. Cretaceous erosional remnants are detached from the interfluves. Landslides are actively developing here. There are especially many of them in the area of ​​the villages Livenka, Eryshevka, Shestakovo.

Group 3 - analyzes the Oka-Don lowland.

To the north of the Kalachskaya and east of the Central Russian Uplands, the Oka-Don lowland plain is located on the territory of the region. It is perfectly expressed in the relief of the region and has a number of features inherent only to it. This is a slightly undulating lowland, slightly dissected by ravines and gullies. Its absolute height nowhere exceeds 180 m. The river valleys are cut to a depth of only 25-50 m and are separated by wide and flat interfluves. Wide sandy terraces develop in the valleys. This appearance of the territory depends primarily on the relief-forming rocks.

A characteristic feature of the relief of the Oka-Don Plain can be considered a large number of closed saucer-shaped depressions, often rounded, which are found on watersheds. They are called depressions.

Depressions formed under the action of suffusion. With suffusion, rocks do not dissolve chemically, unlike karst, and the finest particles of soil are carried out along microscopic cracks in the soil. In this case, the volume of the soil decreases and a subsidence is formed. Often, depressions are swamped due to the high standing of groundwater or covered with forest vegetation. Another feature of the relief of the interfluves can be considered sections with a horizontal surface. They are called flatlands. In the conditions of flat areas, atmospheric precipitation does not drain from the watershed, but seeps into soils and soils or evaporates. There is no linear erosion in such places. Bogging in depressions is possible.

Student. After analyzing the text of the textbook and geographic Maps In the Voronezh region, our group came to the following conclusions, which we entered in the table. In turn, representatives from each group fill in the table.

Teacher. The modern relief of the territory was formed for a long time. The territory was flooded by the sea, and sedimentary rocks almost a kilometer thick were deposited in place of the sea basins. Then the sea receded, and in continental conditions, sedimentary rocks were destroyed. This was repeated many times. The main reason for these changes was the smooth vertical movements of the earth's crust. They continue even now. Under the influence of natural processes, the relief is constantly changing. Currently, the relief is influenced by flowing waters (rivers and streams), melt and groundwater, landslides, as well as human economic activity. Work in progress internal forces Earth - oscillatory movements of the earth's crust occur in our country with speeds from -2 (lowering) to +4 mm / year (uplift). They affect river slopes, surface water flow rates, channel, slope, karst and other processes of modern relief formation.

The unequal speeds of tectonic movements led to the separation of the Central Russian, Kalach Uplands and the Oka-Don Plain.

Teacher. To consolidate the new material, I propose to perform the following tasks.

Fill the gaps.

A) Lowlands and uplands are varieties -_______________________.

B) Lowlands have a height of ________ m above sea level, highlands ________ m above sea level.

C) All the highlands and lowlands of the region are within the large ____________________________ plain.

D) the absolute heights of the Central Russian Upland - _____________ above sea level.

E) The absolute heights of the Kalach Upland reach ______________ m.

2. What form of relief are we talking about?

A) Its surface is wavy. Here there are significant fluctuations in heights, reaching 100-125m. It is cut by valleys and gullies ______________.

B) This landform is much lower and more even. The highest heights do not exceed 170-180 meters. The surface is flat. Valleys and beams are less common, they are not cut so much _____________________.

3. What are they talking about and what do these numerical data mean?

A) "25 million years ago" ________________________

B) “higher by 200-250m” _______________________

C) "rise at a rate of 2 mm or more per year" __________________________________________________________________

D) "immersion at a rate of 2 or more mm per year" _______________________.

Homework.

On "5" and "4" - using a topographic map, draw a profile of the territory of your region. On "3" Using physical card Voronezh region contour map sign the Central Russian and Kalach uplands, the Oka-Don lowland.

The territory of the Bryansk region is located in the southwestern part of the Center of the East European Plain, where three of its major orographic units merge: Smolensk and Central Russian Upland and Dnieper lowland , which do not have clearly defined boundaries in the relief (Fig. 14).

Rice. 14. Large landforms of the Bryansk region

(Shevchenkov, Shevchenkova, 2002)

uplands: 1 - Central Russian; 2 - Smolensk: a) Dyatkovskaya, b) Aselskaya; 3 - Dubrovskaya; 4 - Vshchizhskaya; 5 - Bryansk; 6 - Trubchevskaya; 7 - Starodubskaya.

lowlands: 8 - Iputskaya; 9 - Sudostskaya; 10 - Desninskaya.

Smolensk Upland valleys of the Desna and Bolva rivers is subdivided into Rognedinsky, Dyatkovskaya and Zhizdrinskaya hills. The Smolensk Upland with its southern outskirts occupies the interfluve of the Desna and Ugra rivers, and within the region - Ostra-Desna, Desna-Bolva and Bolva-Ressety-Zhizdra. Marks of 200–220 m predominate, to the north near the city of Spas-Demensk (Kaluga region) up to 280 m. The watershed areas are occupied by flat and gently undulating plains, often swampy. However, in contrast to the Central Russian Upland, there is often a hilly, ridge and hollow relief, with large lakes. Between the rivers Seshcha and Gabya stretches the Aselskaya ridge with elevations of 250–292 m.

Central Russian Upland, which occupies the eastern outskirts of the region, by the valleys of the Snezhet, Navli, Nerussa and Seva rivers is subdivided into Karachevskaya, Navlinskaya, Brasovskaya, Komarichskaya and Sevskaya uplands. They represent, as it were, “spurs” of a single Central Russian Upland, bounded in the west by the valleys of the Desna and Resseta rivers and the Paltsovskaya hollow located between them. The Central Russian Upland on the eastern border of the region has elevations up to 274 m. Its watershed part is a flat or gently undulating plain, along the river valleys deeply and densely dissected by gullies and ravines. western slope The upland is complicated by terraced steps and indistinct ledges. The rear parts of the steps are often swampy. Wide flat submeridional hollows stretch between the river valleys. Often they also cross the main watershed between the basins of the Desna and Oka rivers at elevations of 200–220 m. "Bryansk" sands.

Dnieper lowland, the northern periphery of which is often referred to as the Polesskaya or Desninsko-Pripyat lowland plain, wide "bays" wedged to the north along the valleys of large rivers. Within the area they form Desninskaya, Sudostskaya and Iputskaya lowlands. They are separated by small "island" Starodub and Bryansk uplands. Starodubskaya the hill with marks up to 230 m has no clear boundaries. Flat and gently undulating watershed plains alternate with flat wide swampy hollows. Only along the western slope there are areas of hilly and hilly-ridge relief. Depressions are widespread everywhere, karst funnels are not uncommon. Bryansk Upland stretches along the right bank of the river. Gums from the village. Dubrovka to the city of Trubchevsk, its absolute height decreases from 288 m south of the village of Dubrovka, to 212 m near the city of Trubchevsk, and the relative height above the river's edge. The gingiva is 70–90 m. By the valleys of small rivers and through hollows, it is divided into Dubrovskaya(288 m), Vshchizhskaya(228 m), Bryansk(234 m) and Trubchevskaya(212 m) island highlands.

Topographers usually draw the boundaries between highlands and lowlands on maps along an isohypse of 200 m. For low platform plains, including the East European plain, which has an average height of 142 m, this “entails a distortion of the outlines and areas of large landforms.” Within the region, the boundary between the highlands and the lowlands most accurately reflects the isohypse of 180 m. It approximately corresponds to the average height of the region.

AT general plan, the surface of the region is represented by three large monoclinal plains (slopes). This well emphasizes the general pattern of the river network. The west and the center of the region are occupied by the vast Desninskaya monocline with a general southwestern slope of 0.5 m/km. The extreme north of the region is occupied by the Zhizdrinskaya monocline. Left bank of the river. Gums below the confluence of the river. Bolva is occupied by the Central Russian monocline with a total western slope of 1.5–2.0 m/km. The slopes were formed during the retreat of the seas in the Cretaceous and were caused by tectonic processes (Meshcheryakov, 1965).

The most high point area (292 m) is located on the Asselskaya ridge on the border with the Smolensk region. The smallest height (118 m) is located in the extreme southwest at the confluence of the river. Tsats in the river. Dreams. The total height difference is 174 m. For the East European Plain, such a height difference should be considered significant. The difference in absolute heights between the valleys of large rivers and neighboring watersheds usually does not exceed 100 m, more often 40–60 m. Only on the left bank of the river. The gums between the watersheds on the Central Russian Upland (up to 274 m) and the valley of the river. Desna (133 m), the height difference at a distance of 50 km reaches 141 m. The maximum height difference at short distances is confined to the right bank of the river. Gums in the Bryansk-Trubchevsk section (70–100 m). In general, against the background of the East European Plain, the territory of the region stands out as a relatively elevated area. This determined the deep incision of river valleys and a dense network of ravines and gullies.

The relief of the watersheds is represented by flat or gently undulating monoclinal stepped plains, densely and deeply (by 30–50 m) dissected in the riverine parts by ravines, gullies, and valleys of small rivers. The surface is almost everywhere complicated by numerous (20–70 per km2) depressions. From the side of the river The gums upland is bounded by a high steep ledge, dissected into a "fringe" by ravines and complicated by large landslide cirques and "terraces".

Lowlands (with elevations less than 200 m) occupy about 85% of the region's area. The largest Iputskaya the lowland is a monoclinal plain with elevations from 190 m in the north to 130 m in the south. The relief is dominated by flat terraced sandy plains, the surface of which is complicated by depressions, funnels, sandy ridges, along the periphery - by a hilly-ridged glacial relief. They have a similar relief Desninskaya and Sudost lowlands. In the south of the region, all three lowlands merge into a single lowland plain Bryansk woodland.

The relief of any territory consists of forms different ages and different genesis, formed during long-term and constant interaction tectonic movements and volcanism (endogenous processes) and the work of numerous external (exogenous) processes.

In geomorphology, it is customary to distinguish between structural relief, created with the leading role of internal (endogenous) processes, and sculptural relief, in formation, which was determined by external (exogenous) processes. However, there are landforms that are difficult to attribute to one of these types. In their formation, the role of tectonics, denudation or accumulation, and lithology (composition and occurrence of rocks) manifested itself equally noticeably (structural-denudation relief).

structural relief

Morphostructure is understood as landforms that have arisen with a leading role in the relief formation of the geological structure of the earth's crust (mainly tectonic movements). The restructuring of tectonic movements caused the destruction of the ancient ones and the formation of younger morphostructures in their place. Many ancient morphostructures turned out to be cut off by denudation or buried by accumulation and are not expressed in the open surface (Meshcheryakov, 1960). However, they provided strong influence on the subsequent development of the relief and sedimentation. Often, not only young superimposed, but also ancient inherited morphostructures are reflected in the modern visible relief. Complex correlations of morphostructures of different ages are also typical for the territory of the Bryansk region.

On the territory of the Bryansk region, large tectonic landforms on the surface of the crystalline basement are covered by a sedimentary cover 200–900 m thick and are currently buried. In the relief of the modern visible surface, they are expressed in the event that they experienced the latest movements and turned out to be inherited. However, during a very long platform stage in the development of the earth's crust, a significant restructuring of the structural plan took place.

In the Paleozoic, Mesozoic, and Cenozoic, younger superimposed structures were formed, which arose and developed during periods of increased tectonic activity of the platform, were reflected in the relief, and then lost tectonic activity and were cut off by denudation or overlapped by marine sediments. The visible surface reflects the nature of tectonic movements during newest stage the history of the earth. To identify the amplitude of tectonic deformations of the surface for modern times usually the position of the Oligocene leveling surface is used.

In the relief of the visible surface of the Bryansk region, the following morphostructures are distinguished: Desninskaya , Sudostskaya, Iputskaya and Zhukovskaya lowland-troughs ; Bryansk, Starodubskaya, Spas-Demenskaya (Desninsko-Zhizdrinskaya) and Central Russian Uplands-monoclines.

Desninskaya lowland-trough It is located between the Central Russian and Bryansk uplands and is expressed in the relief in the form of a submeridional elongated flat low-lying hollow. At present, the main part of the lowland-trough is occupied by a wide valley of the river. Gums. As the newest morphostructure, it was formed in the Post-Cretaceous, although the trough itself existed already in the Pre-Jurassic and Cretaceous. On the surface of the Turonian, the Desna trough lies 40–60 m below the neighboring Dmitrov uplift of the Central Russian anteclise, and on the surface of the Upper Jurassic section, the height difference reaches 80–120 m. The trough is also pronounced on the surface of the platform basement. Thus, the morphostructure from the Jurassic period has developed inherited.

The boundaries of the Desninskaya lowland-trough are determined by linear structures. In the west, it is bounded by a trough-like trough with an amplitude of up to 10 m along the structure of the Upper Cretaceous deposits, which separates the Bryansk neotectonic uplift and the Desna trough. The r. Gum. The eastern boundary is defined by the latest Sevskaya flexure, clearly expressed over all horizons of the Cretaceous system, with an amplitude of more than 100 m (Fig. 12). In the north, the Desninskaya Lowland is bounded by the latest structural trough along the Karachev–Bryansk line. The newest tectonic uplifts, which were more actively manifested along the eastern periphery of the trough, created a general western dip of the surface and an asymmetric structure of the river valley. Gums.

The Desna trough is complicated by diagonal and transverse linear structures of recent origin: Trubchevsk-Navlya, Novgorod-Seversky-Dmitrov-Orlovsky, Trubchevsk-Sevsk, Karachev-Zhukovka and others. These structural lines control smaller local structures: the Navlinskoe, Shchatrishchevskoe, Beloberezheskoe, Snezhetskoe, Pesochinskoe, Lyubokhonskoe uplifts and the Znob-Novgorod, Svenskaya, Raditskaya, Polpinskaya, and Gorelkovskaya depressions (Raskatov, 1969; Similar et al., 1970). Local structures were especially actively formed in the Cretaceous and Neogene periods, and some have retained their activity to the present and are directly reflected in the visible relief. Transverse structures complicated the surface of the Desna trough and gave the Desna valley a beaded shape. The valley extensions coincide with the intersections of the structure with transverse troughs. The narrowing of the valley is confined to areas where the “structural capes” of the western slope of the Voronezh anteclise (Navlinskoe uplift) enter the trough. The activity of transverse structures created a stepped surface of the Desninskaya lowland-trough and manifested itself in the features of floodplain erosion-accumulation processes, meandering of the channels of the Desna and its tributaries, in the height and structure of the floodplain and above-floodplain terraces. New structural lines control the valleys of the Navli and Snezhet rivers. Nerussy, Seva, Sudost, as well as the watershed elevations separating them.

Rice. 15. Occurrence of Mesozoic deposits on Central Russian

and Bryansk monoclines. Sevskaya Flexura

(Shevchenkov, Shevchenkova, 2002)

The Desna trough is confined to a strip of NE-trending Proterozoic folds. In the basement of the platform, there is a band of gneisses penetrated by numerous mafic and ultramafic intrusions. Geophysical methods revealed two large faults here, between which the gneiss zone of the Desna trough is located. Such a spatial coincidence suggests a connection between the newest structure and the structure of the Proterozoic crystalline basement.

Iputskaya lowland-trough occupies the western, most subsided periphery of the Desninskaya neotectonic monocline. According to the foundation of the platform, it corresponds to the Unech depression. The absolute heights of the lowland decrease from 190–200 m in the upper reaches of the Iput to 140–150 m in the extreme southwest of the region. The average slope of the surface is about 0.25 m/km. In relation to the neighboring hills, the surface of the monocline is lowered by 40–50 m. Within the trough, the newest linear structures of predominantly northeastern and meridional strike, corresponding to the general strike of the trough, were revealed. From the east, the trough is limited by the Novozybkov–Zhiryatino structural line. It follows the border of the Bryansk-Starodub zone of Late Proterozoic granite intrusions and the Surazh-Kletnyanskaya zone of gneisses with Late Proterozoic intrusions of mafic rocks. Two structural lines are traced along the Surazh–Zhukovka line. Between them laid the middle segment of the river valley. Iput on the section Ushcherpye-Dektyarevka. The valley of the river follows the breakline. Conversations between Khotimsky and Krasnaya Gora. The rivers coincide with the submeridional linear structure. Paluzh, meridional section of the river. Conversations at the village of Krasnaya Gora, a through hollow at the lake. Kozhany, r. Vikholka and meridional segment of the river. Iway below the village of Katichi. In general, the latest structural lines control the pattern of the modern water network.

The Iputian trough as a relatively lowered structure existed as early as the Devonian. It remained active in the Jurassic and especially in the Late Cretaceous. The prolonged subsidence of the trough determined the accumulation of a thick (up to 900 m) sedimentary cover in it. The lowering of the trough during the Jurassic and Cretaceous periods was about 150 m. The Oligocene leveling surface lies at heights of 160–170 m, which is 40–50 m lower than on the Bryansk Upland. Consequently, the relative subsidence of the Iputsky trough continued in the Neogene-Quaternary. Therefore, the rivers are not deeply incised, and outwash plains are widely developed in the Quaternary relief. The monoclinal structure of the trough is complicated by local uplifts, which in the relief correspond to small island heights, and depressions, which are associated with valley expansions and waterlogged hollows, transverse sublatitudinal flexures, along which the bed dip increases by 2–3 times (Figs. 15, 16).

Figure 16. Structure of the sedimentary cover of the Bryansk monocline

(Shevchenkov, Shevchenkova, 2002)

Bryansk upland-monocline occupies the interfluve of the Desna and Iput with a complex, but mostly elevated relief (Fig. 16). The boundaries of the upland-monocline are quite clearly expressed both in the structure of the Mesozoic sedimentary complex and in the structure of the crystalline basement. In the east, the monocline is bounded by the Desninsky trough and the latest Bryansk–Novgorod Seversky structural line, in the north by the Zhukovsky trough, and in the west by the Iput trough. The rise has the shape of a submeridionally elongated flat structural “nose” of the recent monocline, uplifted along the northern periphery up to 220–300 m. The monocline is complicated by recent troughs and uplifts of predominantly diagonal orientations with amplitudes of 20–40 m, which are reflected in the visible relief as oval hills and wide hollows. The Starodubskaya, Trubchevskaya, Bryanskaya, Vshchizhskaya, Dubrovskaya uplifts and the Sudostskaya hollow are well expressed. The newest linear structures Kletnya–Vygonichi, Pochep–Vygonichi, Starodub–Romassukha, Semyonovka–Trubchevsk, Pogar–Mglin, and Trubchevsk–Pochep are reflected in the relief (Raskatov, 1969).

On ledges, where the thickness of the Quaternary sequence is insignificant (2–10 m), the Oligocene surface is uplifted up to 200–210 m, the maximum cover of glacial and alluvial deposits (up to 20–40 m) is confined to the hollows, and the Oligocene surface here is lowered and strongly eroded, and it is difficult to judge its original position. However, on the surface of the Turonian Stage, the Sudost trough turned out to be lowered by 40–55 m in relation to the Bryansk and Starodub uplifts. continued relative growth of structures. The total value of the recent uplift on the Bryansk morphostructure was somewhat smaller than on the Central Russian anteclise, but the tectonic development of morphostructures in recent times proceeded in the same way. The formation of the Bryansk monocline as a relatively uplifted area began as early as the Devonian, when its relative height reached 20–50 m. At the end of the Devonian, with a general uplift of the territory, local structures with an amplitude of up to 50 m and at 300–350 m along the southern pericline, the activity of local structures decreased, and then again noticeably increased in the Late Cretaceous with a general uplift of the region.

The latest uplift of the Bryansk upland-monocline was accompanied by erosional dissection of its surface, which was especially pronounced in areas of local uplifts and along linear structures, along which block faults created significant relief energy. The general orientation of the ravine-gully network coincides with the direction of the main structural lines of the Proterozoic inception. So between the city of Bryansk and the village of Dobrun, 70% of the ravines have a diagonal orientation, of which 38% are northwestern and 32% are northeastern. Along the northern outskirts of the Bryansk Upland, 51% of the ravines are oriented northeast and 21% are northwest oriented. Meridional and latitudinally oriented ravines are of subordinate importance; they account for less than 30% of the forms. The river network has an even greater structural conditionality. The depth of dissection is significant, especially on local uplifts, and reaches 50–70 m with a density of ravine-gully network up to 1.0–2.5 km/km). The Dnieper glacier blocked the Bryansk Upland to the west of the line with. Negotino, the watershed of the Desna and Sudost, the village of Ostraya Luka on the Desna (to the north of Trubchevsk). However, being inactive, it did not introduce noticeable changes into the general pattern of the structurally conditioned surface.

Zhukovskaya lowland-trough It is confined to the tectonic trough of the same name of the latest inception and is expressed in the relief as a sublatitudinal trough. The deflection coincides with the fracture of the crystalline basement (Karachev–Zhukovka according to G.I. Raskatov, 1969). The Karachev fault is crossed by linear structures of northeastern origin near the city of Bryansk (Desninskaya) and near the village of Zhukovka (Surazhsko-Kletnyanskaya). In these areas, the trough loses its linear orientation; wide isometric basins with radially converging rivers are clearly expressed in the relief.

The Zhukovsky trough in the pre-Quaternary surface (marks 80–120 m) can be traced to the city of Roslavl. Glacial tongues produced a significant plowing of bedrock along the axis of the trough and left it along its sides, and near the village. Nomadic and in the axial part of the trough, large pressure and accumulative ridges with glaciodislocations (Pogulaev, 1956; Shik, 1961). Glacial accumulation divided a single pre-glacial depression into a number of "lowlands" (Zhukovskaya, Voronitskaya, Osterskaya). Up to 100 m of Quaternary sediments have accumulated in the trough. In the visible relief, it was inherited by a modern wide hollow, along which there was a runoff of glacial waters that left an outwash plain (Fig. 19).

There are several local uplifts along the southern flank of the Zhukovsky trough, which are controlled by the latest fault. They make up the elevated northern flank of the Bryansk Upland, a monocline. To the north of the axis of the trough, Carboniferous deposits appear, the slope of the Devonian layers noticeably increases, and the thickness of the Cretaceous and Jurassic deposits decreases. Consequently, the trough is a sublatitudinal geological and geomorphological boundary.

Spas-Demenskaya Upland-uplift occupies the Desninsko-Ugran interfluve. In the general scheme of the relief of the Center of the Russian Plain, the Spas-Demensky uplift is included in the amphitheater of uplands (Valdai, Smolensk, Spas-Demensk, Central Russian), which borders the Upper Volga basin from the west and south.

A long period of pre-glacial denudation, which created a deeply (up to 100–120 m) dissected surface, and glacial gouging greatly altered the Oligocene leveling surface. On the eastern periphery of the Spas-Demenskaya Upland, the marks of the sub-Quaternary relief reach 200–210 m, in the west and south they decrease to 180 m. The relative height of the uplift in the pre-glacial relief is about 50 m. Desna and Dnieper.

The Spas-Demenskoe uplift represents the latest morphostructure, however, the formation of the structural boundary between the Moscow syneclise and the Dnieper-Desna depression began much earlier. On the surface of the basement, an uplift in the form of a northwestern “nose” of the Voronezh anteclise is well expressed. According to the structure of the sedimentary cover of the Devonian and Carboniferous age, the axial uplift zone is less pronounced, but the dip of the layers towards the Moscow syneclise sharply increases. In the Mesozoic, the uplift axis was clearly expressed in the relief, and the boundary of the distribution of Cretaceous deposits coincides with it. The Cretaceous monocline is replaced by a "Carboniferous plateau". The total value of the neotectonic uplift was 340 m, which is 20–30 m more than in the Bryansk monocline.

The area under consideration has experienced complex geological development and has several structural levels. According to the basement, this is the structural "nose" of the Voronezh anteclise, to which the highest occurrence of the surface of the Devonian deposits is confined. Its activity in the Devonian caused the formation of local structures with an amplitude of several tens of meters against the background of a general uplift. In the Mesozoic, this area in relation to the Voronezh and Belorussian anteclises represents a tectonic trough. However, an area of ​​relative subsidence existed here throughout the Devonian and Carboniferous periods, and inheritance developed into the Mesozoic. Thus, in the basin of the Upper Desna, there was a superposition of a diagonal northeast trough on the structural cape of the northwest trending anteclise. Therefore, the foundation of the platform here has a block structure, which in the structure of the sedimentary cover is reflected in the alternation of relatively large local uplifts and depressions with an amplitude of up to 50 m along the structure of the Paleozoic sedimentary cover. Intense magnetic anomalies are confined to positive structures, which indicates the connection of local structures with the structure of the basement.

The Pleistocene glaciations brought about a significant restructuring of the relief of the Oligocene polygenetic surface, especially along the western periphery of the upland, where glacial exaration created deep glacio depressions. On the eastern periphery, the visible relief to a greater extent reflects the features of the sub-Quaternary surface, and in the Quaternary relief, outwash plains are most widely developed. Along the northern and western periphery, the main role is played by a large hilly-ridge accumulative glacial and water-glacial relief.

Central Russian upland-anteclise in terms of almost completely coincides with the selected G.I. Raskatov (1969) The Central Russian anticline is the newest structure formed on the Voronezh anteclise and the southern flank of the Moscow syneclise. It enters the boundaries of the Bryansk region only by the western margin and is expressed in the relief of an elevated up to 250–275 m, strongly dissected denudation-stratal plain, descending in steps towards the Desna trough. The axis of the recent anticline has a submeridional orientation and a noticeable angular (by 30–40°) unconformity with the Precambrian structure of the Voronezh anteclise, with respect to which it is superimposed. The Central Russian upland-anteclise is complicated by structures of a local order, which have received a direct expression in the modern visible surface.

Dmitrov uplift occupies the watershed of the rivers Navli, Nerussa and the left tributaries of the Upper Oka - Tsona and Kromy. The summit surface is located here at heights of 240–260 m; The recent relative uplift of the upland is indicated by the deep incision of the valleys and the low thickness of the alluvial strata. The basement surface is complicated by thrust faults with a relative height of up to 300 m or more, the strike of which coincides with the meridional axis of the Dmitrov uplift. Basement projections in a more smoothed form are reflected in the Paleozoic sedimentary cover and, to a lesser extent, in the Mesozoic structure. The western slope of the Dmitrovsky uplift is bounded along the basement by a fault step with an amplitude of up to 100 m. western fall seams up to 26 m/km near Sevsk (Fig. 15). The Sevskaya structure coincides with the western edge of the band of intense magnetic anomalies, is apparently laid down along a crystalline contact, and was formed during a block displacement in the Post-Cretaceous. The structure continued to develop in the Quaternary, as evidenced by the socle structure of the lower terraces of the rivers.

The Dmitrov uplift is complicated by the linear structures Sevsk-Mikhailovka-Livny, Dmitrovsk-Orlovsky-Kromy, Karachev-Bryanek, Trubchevsk-Navlya and local uplifts. In relief, the most total reflection received Sevskoe, Navlinskoe, Paramonovskoe and Novoyalta uplifts. The total uplift on the Dmitrovskaya structure in recent times was about 250 m. The relative uplift of the morphostructure began as early as the end of the Cretaceous, as evidenced by the wedging out of layers from the Turonian to Maastrichtian stages and the absence of Paleogene-Neogene deposits. But the most significant tectonic activity manifested itself in the Neogene-Quaternary time, when the relative height difference reached 100 m or more. By this time, the foundation and deepening of the main valleys and gullies should be attributed.

Thus, the main features of the relief of the Bryansk region are largely due to the latest tectonic movements, which developed mainly inherited from more ancient structures. modern structure The slab cover, including the morphostructure, was formed in the process of long-term epeirogenic movements of significant amplitudes of individual foundation blocks, which took place against the background of a general subsidence or uplift of the entire slab. Positive structures (Voronezh anteclise), especially in the central parts, were the most conservative to oscillations, and marginal syneclise zones and tectonic troughs showed the greatest activity, especially during subsidence. On the example of the Desna basin, it is quite clearly seen that the main structures of the basement and the main structures of the cover reflect the block structure of the earth's crust.