CAUCASUS

Relief and geological structure

The diversity of the relief makes it possible to distinguish within the Caucasus several orographic regions: Ciscaucasia, located between the Kuma-Manych depression and the mountains, and on the actual mountain structure of the Greater Caucasus.

Within Ciscaucasia the Kuban-Azov lowland stands out, the mountains of the Mineralnye Vody group (up to 1400 m.) - in the center, and the Tersko-Kuma lowland in the east.

Ciscaucasia occupies a vast territory, which is based on the Scythian plate. The surface of the slab foundation has a rather complex structure. Along its northern border is Manych trough(up to 6 km), stretching almost 700 km from the Sea of ​​Azov to the Caspian Sea. In relief it corresponds Kumo-Manych depression. The central part of Ciscaucasia is occupied by Stavropol Upland, reaching the highest heights in the southwest (Mount Strizhament - 831 m). The hill breaks off in clear ledges to the southwest (near Armavir its height reaches 326 m) and to the south. Its slopes, facing the northwest, north and northeast, are gentle. At the heart of the elevation is Stavropol vault, within which the depth of the foundation varies from 0.5 to 2.5 km. In the central part of the dome, the lower horizons of the sedimentary cover (Т-К) are absent, and the Aptian, Albian, and Upper Cretaceous deposits are thin.

To the west of the Stavropol Upland is located Kuban-Azov lowland, which is based on Azov-Kuban depression with a foundation depth of up to 3 km. The eastern part of Ciscaucasia is occupied Tersko-Kuma lowland, dated to the depression of the same name, within which the basement lies at a depth of 6 km or more. The Tersko-Kuma lowland is the southwestern outskirts of the Caspian lowland.

The upper layer of deposits of the lowland plains of Ciscaucasia is represented by loess-like loams, Neogene and Paleogene sandy-argillaceous, sometimes carbonate continental and marine deposits.

South of the Stavropol Upland there is a peculiar Mineral group of island mountains- laccoliths (Beshtau - 1401 m). To the west of it along the foot of the mountains stretches Kuban marginal foredeep, presented Kuban sloping plain, and to the east - Terek-Caspian trough, the northern part of which goes under the Tersko-Kuma lowland, and the southern slope is complicated by anticlinal folds Tersky(up to 664 m) and Sunzhensky(up to 926 m) ridges. From the south, they are adjoined by sloping plains (Kabardinsk, Ossetian, Chechen), gently descending from the foot of the Greater Caucasus to the north and northeast. The sedimentary cover in the marginal troughs reaches a thickness of 10-12 km. The upper part of the cover is represented by thick strata of fluvioglacial and alluvial boulder-pebble deposits overlain by loess-like loams.

The mineral-growing (Pyatigorsk) island mountains, the Tersky and Sunzha ranges occupy an intermediate position between the Greater Caucasus and Ciscaucasia (see Fig. 1). Both genetically (anticlinal folds and intrusions of laccoliths are associated with tectonic movements and volcanism of the Greater Caucasus), and morphologically (rather high mountain ranges and folded ridges), they are close to mountainous areas, but are confined to the marginal foredeep, and therefore are assigned to Ciscaucasia.

The most characteristic orographic area - The Greater Caucasus, a powerful folded system (4-5 thousand m), which is divided into the axial part, the Dividing Range, the Side Range, the Northern and Southern slopes. To the south stretches a strip of intermountain lowlands - Colchis and Kuro-Araks, separated by a low Suram ridge. Further to the south stretches the region of the Transcaucasian Highlands, framed from the north and northeast by chains of ridges of the Lesser Caucasus. In the southeast of Transcaucasia, the Talysh mountains stretch with the Lenkoran lowland adjoining them. The inner regions of the Transcaucasian Highlands are called the Javakhetian-Armenian Highlands, which is part of the vast uplands of Western Asia.

Rice. 1. Orohydrographic scheme of the Caucasus

The position of the Caucasus between very contrasting regions in nature, the influence of each of which can be traced primarily in the adjacent territories, increases the diversity of its nature. In the western and central parts of Ciscaucasia and on the northern slope of the Greater Caucasus, the influence of the southern Russian steppes can be traced. The nature of the Central Asian deserts left its mark on the eastern part of Ciscaucasia (through the Caspian lowland). The nature of the Black Sea coast of the Caucasus and the southwestern slopes of the mountains is influenced by the subtropical eastern Mediterranean. The areas of influence of neighboring territories are quite clearly demarcated by the orographic boundaries of the Greater Caucasus and the transverse uplift: the Stavropol Upland - the Central Caucasus - the Likhi Range, which are climatic divisions.

In the Caucasus, the dependence of hydroclimatic and biogenic components on the relief is very clearly revealed, the influence of geological structure on other components of nature: runoff, soil, vegetation. The mountains of the Caucasus are characterized by altitudinal zonality, which varies quite significantly from the western outskirts to the eastern. On the example of the Caucasus, the main features of nature and the patterns of their change inherent in mountainous countries are perfectly traced.

The nature of the Caucasus has been studied quite well. Many travelers and researchers of various specialties conducted their research here. At the end of the 18th century, during a trip to the southern regions of Russia, the North Caucasus was visited by P.S. Pallas. A quarter of a century in the mountains of the Caucasus worked G. Abikh, who published in 1858 and 1859. summary work on the orography and geology of the Caucasus. The accession of the Caucasus to Russia facilitated and accelerated its exploration by Russian travelers. Geologist M.V. worked here. Mushketov, soil scientist V.V. Dokuchaev, biogeographers N.M. Albov, A.N. Krasnov. Later, the geological structure of the Caucasus was studied by I.G. Kuznetsov, V.P. Renhardten, E.E. Milanovsky, V.E. Khain, N.V. Koronovsky and many others; relief - I.S. Schukin, N.V. Dumitrashko, N.A. Gvozdetsky and others; climate - I.V. Figurovsky; glaciers and avalanches - G.K. Tushinsky, S.V. Kalesnik; soil - S.A. Zakharov, A.I. Prasolov, S.V. Zonn and others; organic world- A.A. Grossheim, N.A. Bush, N.I. Kuznetsov, K.A. Satunin and others. Great contribution to comprehensive study the nature of the Caucasus was introduced by B.F. Dobrynin and N.A. Gvozdetsky.

The Greater Caucasus is a majestic mountain structure. Its width varies from 32 km near Novorossiysk to 180 km on the Elbrus meridian and 160 km in Dagestan. The Greater Caucasus is a large asymmetric meganticlinorium. The anticlinal structure is the most characteristic geological feature of the Caucasus. In its core, in the western and central parts of the mountain structure, Precambrian, Paleozoic and Triassic rocks of the lower structural stage are exposed.

Rice. 5. Geological profile through the cuestas of the Caucasus

Rice. 6. Geological profile through Inner Dagestan (according to A.E. Krivolutsky)

They are successively bordered by Jurassic, Cretaceous, Paleogene and Neogene strata of the upper structural stage.

Usually the Greater Caucasus is divided into several cross sections(segments) and three longitudinal zones(belts): axial uplift, represented by the Main, or Watershed, and Lateral Ranges with heights of more than 3000-4000 m (with the exception of the extreme northwest); the northern slope belt, which includes a system of parallel ridges, gradually lowering to the north; belt of the southern slope, located outside of Russia.

Along the strike of the Caucasus, four segments of different heights are usually distinguished. The highest is Central Caucasus located between Elbrus and Kazbek. Here are all the "five-thousanders" of Russia: Elbrus(5642 m), Dykhtau(5204 m), Shkhara(5068 m), Dzhangitau(5058 m), Kazbek(5033 m). Often the peaks of the Lateral Range rise higher than the Watershed Range. Both ranges are composed of solid Precambrian crystalline rocks, and the depression separating them is formed by the Lower Jurassic.

From Elbrus to Mount Fisht stretched Western Caucasus. It is below the central one. The highest point here is Dombay-Ulgen(4046 m). The watershed ridge is composed of crystalline rocks, and the Bokovoy ridge is composed of highly metamorphosed Paleozoic strata. The heights of the ridges decrease to the northwest.

From Fisht to the Taman Peninsula stretches Northwestern Caucasus, represented by the mid- and low-mountainous Black Sea chain. Its heights decrease from Mount Fisht (2868 m) to Novorossiysk to 500 m. The mountain ranges are composed of easily destroyed rocks of the Jurassic, Cretaceous and Paleogene. The Taman Peninsula also tectonically belongs to the Greater Caucasus, but the absence of mountainous terrain allows to attach it to Ciscaucasia.

In the axial zone of the Central and Western Caucasus, glacial landforms dominate: sharp rocky ridges, pointed peaks (carlings), glacial cirques and cirques, and trough valleys. To the north and northeast of the Bokovoy ridge there is a system of cuestas of the northern slope: the Rocky ridge, armored by Upper Jura limestones, Pasture, Wooded, composed of Cretaceous and Paleogene strata.

The Eastern Caucasus stretches east of Kazbek. It is lower than the Central, but higher than the Western. A number of its peaks exceed 4000 m. The Vodorazdelny and Bokovoy ridges are also clearly visible here, but they are composed mainly of Jurassic shale. Here, glacial landforms are much less pronounced due to less glaciation in the past and present, as well as the predominance of easily destroyed clay shales, which does not contribute to the preservation of ancient landforms.

In front of the axial ridges within the northern slope of the eastern Caucasus lies an orographically complex mountainous region of Inner Dagestan, almost enclosed by the Andiysky, Salatau, Gimrinsky and other ridges, which is cut by four Koisu, forming the Sulak River. Inner Dagestan is composed mainly of Lower and Middle Jurassic shales (see Fig. 3). Only in its northern part are Upper Jurassic and Cretaceous limestones, which form high cliffs along the sides of river valleys, acquiring the appearance of tight deep canyons. To the north and east of Inner Dagestan lies Outer Dagestan with soft rounded relief forms.

Spreading glacial relief characteristic of the highlands, however, the predominant type of relief in the mountains and in Ciscaucasia is water erosion. Depth of erosional dissection in the Caucasus Mountains - largest in Russia. In the highlands, it averages 1500-2000 m, but in the upper reaches of the Chegem and Teberda it increases to 2500-3000 m. The deep division of the mountains into valleys is a consequence of young uplifts.

In Ciscaucasia, the processes of river accumulation and gully erosion dominate in uplifted areas. In the lower parts of the mountains, relatively recently still piedmont plains, the river valleys are widened and incised by only 100-200 m. In the middle mountains, the incision depth increases to 500-1500 m, narrow steep gorges and canyons dominate. In the highlands, the valleys widen again. Trough-shaped troughs worked by the glacier prevail here. Erosive processes dissect the structure of a mountainous country. The different stability of rocks is due to the presence of cuesta ridges and island mountains in the vicinity of Pyatigorsk.

The great depth of dismemberment leads to an increase in gravitational processes, to frequent landslides, rockfalls, screes. The presence of shales and clays contributes to the development of landslides, and the distribution of carbonate rocks - to the development karst forms relief. On the Terek-Kuma lowland, there are eolian forms relief.

The nature and intensity of modern relief-forming processes depend on tectonic structures, lithological features of rocks, and the altitudinal position of the surface, which determines their spatial distribution within the Caucasus.

Colchis and Kura lowlands - tectonic depressions forming the Transcaucasian megasynclinorium. The Colchis lowland is composed mainly of Quaternary rocks, the Kuro-Araks lowland is composed of Neogene and Quaternary deposits.

To the south, the inner zone of folded structures of the Alpine geosynclinal region extends.

Lesser Caucasus in the west it passes into the Pontic Mountains, and its eastern extension - Talysh - is part of Elburz. In the western part of the M. Caucasus (Shavshetsky, Meskhetsky, Trialetsky ridges), Pg deposits are widely developed. This is roughly the structure of Talysh. The Jurassic, Cretaceous, and intrusive bodies participate in the structure of the eastern ranges of the M. Caucasus. Volcanic sedimentary and effusive rocks are widespread everywhere. Dislocated Jurassic, Cretaceous, Paleogene sedimentary rocks are widespread in the Transcaucasian Highlands, among which the products of volcanic activity that occurred in the sea basins play an important role. Limestones predominate, among Pg rocks there are clays, sandstones, carbonate rocks, and flysch accumulations. In the eastern part of the M. Caucasus, the Jurassic and Cretaceous rocks are penetrated in a number of places by powerful intrusions. A characteristic feature of the geological structure of the Javakheti-Armenian Highlands is the wide distribution of lava covers, tuffs and tuff formations of the Jurassic, Cretaceous, Paleogene and Quaternary period. The Talysh Mountains are a complex anticlinorium composed of flysch and volcanogenic deposits of Pg, in the north - sandy-clayey rocks of N.

The length of the territory also determined the diversity of the relief: the European part of the country has a completely different appearance than the Asian one, and there are great differences across regions. 70% of Russia is occupied by plains, among which the most prominent are the East European Plain(within which there are small, up to 250 - 400 m, uplands) in the western part of Russia, and the West Siberian Plain - east of the Urals. They are divided Ural ridge, most of which are mountains 800 - 1200 meters high. Between the Yenisei and Lena is located Central Siberian Plateau dissected by a dense network of river valleys. Mountainous regions with a strongly rugged relief prevail in the east (Aldan Highlands, Verkhoyansk Range, Stanovoye Highlands) and in the south of the republic (Northern Caucasus, Altai, Sayans, etc.), as well as along the Pacific coast.

The relief is directly related to the geological structure of the earth's crust, which is also very heterogeneous. So, the East European Plain approximately corresponds to Russian, and West Siberian - Siberian platform. These are very ancient sections of the crust with a Precambrian folded base, and active mountain-building processes have already been completed there.

Between them is a younger Ural-Altai platform formed in the Paleozoic. Air and water did not have time to destroy the Ural and Altai mountains (formed as a result of the movement of the earth's crust in Cenozoic era), although they worked on them very thoroughly.

From the south, a younger region adjoins the Russian platform North Caucasus, which is characterized by a very significant seismic activity. To the east of the Siberian platform is the Primorsko-Chukotka region, which has a Mesozoic folded base. This is a young area in geological time with a predominance of hills.

The mountainous regions of Kamchatka and the Pacific coast correspond to the belts of recent folding and volcanism. The geosynclinary development there has not yet been completed, which caused the seismic and volcanic activity of the region and left a significant imprint on the entire life of Kamchatka and the Far East. And there is no bad without good: geothermal springs, directly related to volcanism, represent a solid reserve of cheap energy.

The distribution of underground fossils. So, coal basins predominantly correspond to the Carboniferous, Permian, Cretaceous periods. The most important coal basins are

Largest deposits oil and gas associated with Mesozoic and Tertiary deposits in the North Caucasus and Paleozoic deposits in the Volga-Ural and Ukhta-Pechersk oil and gas regions, as well as in Mesozoic deposits in the territory Eastern Siberia and Yakutia.

Iron ores KMA and ore deposits of Karelia correspond to the Precambrian basement. Large ore reserves have also been discovered in the Paleozoic of Siberia and the Urals. Deposits are also associated with the Ural Paleozoic bauxites, copper ores, asbestos, potassium salts, as well as precious and semi-precious stones. Apatity the Kola Peninsula is also rich (proterozoic), where there are also copper and nickel. In the North Caucasus (Mesozoic) mined tungsten, molybdenum, lead, zinc. In the Far East (Mesozoic) - lead, zinc, tin. Other minerals are also mined (mainly in the Mesozoic) gold, platinum, silver, mercury.

The economic significance of these resources for Russia can hardly be overestimated: it is their export that keeps the Russian economy afloat, and it is precisely due to the fact that the cost of energy resources in the country is lower than on the world market that the economic downturn in Russia in recent years has been less sharp than in other republics former Union. However, we must not forget that mineral reserves are by no means unlimited, and many important sources are already close to depletion. Often, mining has a negative impact on environment. Thus, being an indisputable economic trump card of Russia, they also carry whole line problems, without the solution of which it is impossible to save the most valuable resources for posterity.

CLIMATE AND PRECITATION

Located in the north of the mainland, the country includes the Arctic belt, middle latitudes (covering most of Russia), and in the North Caucasus it also captures the subtropical belt. Thus, it is not necessary to speak about the climate of Russia as something monolithic: the differences between the regions are very large. But some patterns can be distinguished, and I would like to dwell on them.

The north-west of the country has a maritime climate, which is caused by the significant influence of the Baltic Sea. Winters are milder here than in other areas at the same latitudes, and summers are relatively cool. However, as you move east, you will notice that the winters are getting colder and the differences between the seasons are becoming more and more sharp. The climate varies from temperate continental in the European part of the country (here one cannot but note the softening effect of the Atlantic) to sharply continental in Eastern Siberia. In Verkhoyansk, the average January temperature is -50°C.

This situation is partly due to the huge area countries, which made the remoteness of most areas from the oceans and seas inevitable (the Arctic Ocean, located beyond the Arctic Circle, is not able to smooth out temperature fluctuations). Another important factor was relief: for example, the mountains in the south of the country block the path of warm air masses from the Asian part of the mainland, and they practically do not affect the climate of Russia. The Far East, located at the same latitude as Siberia, has, however, milder climatic conditions, due to the influence of the Sea of ​​Okhotsk, the Sea of ​​Japan, and the Bering Sea.

The amount of precipitation is directly related to the movement of air masses. It is easy to see that their precipitation depends very significantly on the proximity to the sea. So, in the west, their average annual number is 600 - 700 mm, and when moving to the east, it decreases to 100 mm. per year (Yakutia). At the same time, in the Far East and South-East of Kamchatka, this figure increases by 7-10 times, which is associated with summer monsoon winds from the Pacific Ocean. large masses pair.

The terrain also has a significant effect on the distribution of precipitation: mountains (in simple terms) block the path of rain clouds and do not allow them to move further. Therefore, a lot of rain falls in mountainous areas, while areas located behind large ridges experience a lack of moisture. In the European part of the country, there are no high mountains, and air masses from the Atlantic do not encounter obstacles in their path.

The influence of air temperature is also very large: for the formation of precipitation, evaporation of moisture is necessary, and in warm areas and in the warm season it evaporates much more. That is why the maximum precipitation occurs in the summer months and falls in the form of rain. But, despite this, in Russia almost everywhere (with the exception of the Black Sea coast of the Caucasus) snow cover is typical in winter (from 60 days in the southwest to 260 in the far north).

As we can see, the climate of Russia in most of its parts is very severe, which left its mark on the character of the people (giving the Russian man the ability to live in the most extreme conditions), and on the resettlement of people, and on their occupations. But at the same time, the opposite process has also been noticeable recently: human activity has begun to influence the atmosphere, and this influence is by no means always beneficial.

Emissions from large factories and car exhausts cause excess carbon dioxide which threatens global warming. Even more dangerous is the ever-increasing concentration of sulfur oxide, carbon monoxide, soot and many others in the atmosphere. harmful substances. Already now in large cities and important industrial centers there is a lack of clean air and the growing number of diseases associated with its pollution threatens to become one of the most acute problems. Moreover, in Russia it is more acute than in many other states: the lack of funds does not allow the massive use of modern cleaning agents, and the situation is unlikely to improve radically in the near future.

“Moscow has an advantage over all capitals: in its vicinity, many layers of the earth’s crust are exposed, on which, like the pages of a book, you can read the past destinies of our capital”K. Ruler. 1845

The study of the geological structure of the Russian Plain showed that rocks of sedimentary origin lie on a very ancient crystalline basement with an uneven surface. In the Moscow region, this surface forms a trough called the Moscow Basin with a depth of more than 1600 m. Younger deposits lie above the crystalline basement. The deposits and the conditions of their occurrence indicate that in ancient times the Moscow region was dry land, on which a large amount of clastic material (pebbles, sand) was deposited. Then the territory of the Moscow region for some time was covered by the sea, which quickly became shallow. At this time, strata of clay and limestone were deposited. A new advance of the sea occurred later. The sea that flooded the Moscow region was an open pool with a variety of living organisms: corals, mollusks.

As a result of raising the bottom of the shallow sea, the territory modern suburbs turned into a low coastal plain. The warm and humid climate of that time allowed the development of lush vegetation, the remains of which, having accumulated in thick layers in lakes and swamps, served as the material from which the coals of the Moscow Region coal basin were formed. Limestones come to the surface along the valleys of the Moscow and Pakhra rivers near Podolsk (Myachkovo). The ancient quarries of Myachkovo have long supplied building "white stone", from which the capital at one time received the name "white stone". In the writings of the 17th century. contains numerous indications: “Near the royal city of Moscow, in the village of Myachkovo there is a great mountain, all the white stone is a multitude ... all kinds of house buildings and chambers and all kinds of stone works require that stone ...”

The uneven surface of the limestones is covered with dark clays and sands of the Jurassic period. The gradual lowering of the territory led to its flooding with waters that deposited sands and clays. Dark, almost black clays do not let water through, they are a water-resistant horizon on the slopes, therefore they contribute to the formation of landslides (slow sliding of rock blocks from the slopes). Deposits of such dark clays are found within Moscow near Kolomenskoye, Dyakovskoye, Sparrow Hills, at the mouth of the river. Setun.

Deposition over late period, consisting of quartz sands up to 50 meters thick, have been preserved near Khotkovo (Sergiev Posad region).

The Quaternary period (the youngest in geological history, the time when man appeared on Earth) was marked by the advance into the territory of the northern and central Europe thick layers of ice. The Moscow region was covered by a glacier at least three times. All ancient residual rocks occurring in the Moscow region are covered with later glacial (moraine) deposits. The thicknesses of glacial deposits consist of brown-red clays, there are boulders. For example, the foundation of the building of Moscow University. M.V. Lomonosov is based on powerful loams (13-14 m),

Deposits of melt water (remaining after the glacier) occur on the watersheds and in the ancient valleys, along which the flow paths of these waters once passed. On the watersheds, the thickness of the introductory glacial sands is 1-5 m; and within the ancient valleys reaches 20 meters.

The environs of Moscow and the territory of the city itself for many hundreds and even thousands of years were the habitat and active economic activity man, which caused the presence of a special geological formation - a cultural layer or embankment.

In Moscow, this layer is a brown loose loamy sandy rock, overflowing with various debris, fragments of bricks, pottery, glass, and rusty remains of iron products. It also contains a lot of various rotting substances, animal bones, and on the territory of ancient cemeteries - human bones. Remains of building foundations, ancient decorations, stone and wooden pavements are often found in this rock.

This type of cultural layer is found within Garden Ring. The thickness of the cultural layer varies from 0.5 to 10 m, in the valleys of streams and ravines up to 10-15 m. In other cities, the thickness of the cultural layer usually does not exceed 2 meters, in small villages a few centimeters.

Main questions:What are the main landforms of land? What external and internal processes form relief? What minerals are associated with fold belts and sedimentary cover?

Geological structure. The mainland is part of North American lithospheric plate located at its western edge. The eastern and western parts of the mainland differ in geological structure. Remember what parts the ancestor of Pangea split into?

The basis of the eastern part of the mainland is formed by the ancient North American Platform. In the northeast, the base of the platform is raised and comes to the surface in the form Canadian shield. In the western and southern parts of the mainland, the crystalline basement is overlain by a layer of sedimentary rocks. This part of the platform is a slab by design. The N American Platform is bordered by ancient fold belts, younger in the west than in the east. In the Paleozoic, fold systems joined the platform Appalachians, Greenland and the Canadian Arctic Archipelago, in the Mesozoic - systems Cordillera. Their youngest ranges arose in the Cenozoic during the interaction of the North American and Pacific lithospheric plates.

Relief. The relief of the northern and eastern parts of the region was influenced by the ancient continental glaciation. In the Mississippi Valley, the southern limit of the maximum distribution of the glacier reached the 38th parallel. Under its thickness were Laurentian Upland and peninsula Labrador. The relief forms created by the glacier are widely represented here (hills and ridges with heights of 300-600 m, rounded rocks lamb foreheads(fig.9.1.) and long narrow bays fjords. Glacier deposits - moraines- composed in the north hilly, with heights up to 200-500 m, the surface Central Plains. The glacier brought here numerous boulders, created the basins of modern lakes.

West of the Central Plains from north to south stretched almost 4000 km great plains, indented by numerous deep ravines, and "steps" descending to the Central Plains. (Fig.11.1). Separate sections of the Great Plains are unsuitable for use in the economy. They got the name badlands("bad lands") (Fig. 12.1).

In the south, the Great and Central Plains turn into flat and swampy Mexican and Atlantic lowlands. Along the eastern margin of the mainland, there are heavily destroyed flat-topped Appalachians(G. Mitchell, 2037 m). In the foothills of the Appalachians is the largest mammoth cave. The western part of the mainland is occupied by the powerful Cordillera mountain system (Fig. 13.1). In its northern part, Alaska ridge is highest point continent - mountain McKinley(6194 m).

The Cordilleras consist of three belts of mountain ranges stretching from north to south, separated by belts of plateaus and intermountain valleys. The eastern belt is represented by a wide chain of high rocky mountains At their western foothills, a chain of high-altitude plateaus and plateaus stretches (Fig. 14.1). Among them are volcanic yellowstone and plateau Big Pool, indented by the deepest river canyons Colorado (Fig. 15.1).

The system of mountain ranges frames the plateau and plateaus in the west and is represented by a chain of extinct volcanoes. cascading mountains The rivers abound with picturesque waterfalls and rapids. Lots of hot springs. To the south rise "snowy mountains" Sierra Nevada. In the extreme west are California valley and Death Valley (Fig. 16.1), the lifeless surface of which has an absolute mark of -86 m.

The third, westernmost and youngest belt in terms of age Coastal x ridges stretches along the Pacific coast. The Coast Ranges and the California Valley are part of the Pacific Ring of Fire. In the south of the mainland, all the mountain belts of the Cordillera converge, forming mexican highlands (Fig. 17.1), most of which is covered with solidified lava. The southern part of the highlands is represented by a chain of active volcanoes (Orisab a, 5700 m).

North America is rich minerals. From combustible minerals the most significant reserves of oil, gas, coal. Place of Birth oil and gas are located on the Pacific coast of the United States, the Mexican Lowland, on the shelf of the marginal seas of the Arctic Ocean, Alaska, and the south of the Central and Great Plains. hard coal rich east Central Plains and foothills of the Appalachians. Place of Birth brown coal located on the Great Plains, in the intermountain basins of the Cordillera, in Alaska.

Largest reserves iron ore concentrated in the crystalline rocks of the Canadian Shield in the area of ​​​​Lake Superior and the Labrador Peninsula, in the Northern Appalachians, on about. Newfoundland and Greenland. Non-ferrous metal ores are widespread: copper(Rocky Mountains, Mexican Highlands, Canadian Shield), lead-zinc(Mississippi Valley, Cordillera), bauxites(Fr. Jamaica), nickel(Laurentian Upland, Cuba). Powerful reserves uranium ores are concentrated on the Colorado Plateau, gold- in the Yukon basin and in the southwestern United States. Among non-metallic minerals are allocated reserves phosphorites(Peninsula Florida), asbestos(Appalachian) and potassium salts(south of the Great Plains, Great Lakes region).

1. What are the main landforms of North America. 2*. What is the relationship between the geological structure and the relief of the territory? 3. What minerals are mined on the mainland? 4*. What effect did the glacier have on the formation of the relief of North America?

Orography. The surface relief of Russia is exceptionally diverse and complex. Endless expanses of plains and plateaus are replaced by majestic mountain ranges, low ancient ridges, graceful volcanic cones, vast mountain ranges and large intermountain basins. On hypsometric and physical maps, as well as on images from space, the orographic pattern of the territory of Russia is clearly visible, i.e. mutual arrangement various large landforms: low and elevated plains, plateaus, uplands, mountain ranges and massifs.

When looking at the map, two features of the relief are striking: 1) the predominance of plains in the western and central parts of the country, and mountains along its eastern and partly southern outskirts; 2) lower altitude position of the western part compared to the eastern. The border between them is clearly visible in the prevailing coloring of the map and clearly coincides with the Yenisei valley. The third feature can be traced upon a more detailed examination of the map: the greater height of the southern mountains compared to the eastern ones. The Caucasus and Altai are among high mountains of Eurasia.

In general, the territory of Russia forms a huge amphitheater, open to the north and northwest, therefore, the largest rivers of the country - the Ob, Yenisei, Lena - carry their waters to the north.

Plains occupy about 60% of the country's territory. They stretched from the western borders of Russia to the Lena, from the coast of the Arctic Ocean to the foothills of the Caucasus, Altai and Sayan Mountains. The two largest plains of Russia - East European and West Siberian - belong to the greatest plains peace.

the East European Plain stands out among other plains with the most diverse relief. There are large hills, some marks of which exceed 300 and even 400 m (the highest point of the Bugulmino-Belebeevskaya upland reaches 479 m), and vast lowlands with small hills and ridges scattered over them (in the north) or rather monotonous (Caspian region). The lowest parts of the plain are located in the coastal strip of the Caspian Sea with a height of 26 m. The average height of the plain is 170 m.

In the extreme north-west of the country, within the Kola Peninsula, on the large intrusive massifs of the Khibiny, Lovozero and Monchetundra, some peaks exceed 1100 m; the highest of them - Mount Chasnachorr (1191 m) in the Khibiny.

West Siberian Plain differs in exceptionally uniform relief with slight fluctuations in heights. Only some small areas in the marginal parts of the plain exceed 200 m. It reaches its maximum heights on the North Sosvinskaya (290 m) and Verkhnetazovskaya (285 m) uplands. Almost half of the territory lies below 100 m above sea level. The average height of the plains is only 120 m.

The East European and West Siberian plains are separated by low and narrow (up to 150 km) Ural mountains, only some peaks of which exceed 1500 m. The highest point of the Urals is Mount Narodnaya (1895 m).

In the interfluve of the Yenisei and Lena is located Central Siberian Plateau- a plain raised to a considerable height (up to 400-600 m and higher) and deeply dissected by large river valleys. It reaches its highest heights within the Putorana Plateau (1701 m). The average height of the plateau is 480 m.

To the east, the Central Siberian Plateau gradually passes into the Central Yakut Plain, and to the north it descends in a steep ledge to the North Siberian Lowland.

The mountainous frame in the southwest is represented by mountains Greater Caucasus stretching from the Black Sea to the Caspian Sea. Here is the highest point of Russia - a two-headed Elbrus(5642 m) and all other "five-thousanders". From Altai begins the southern mountainous belt of Siberia. It is represented by high and mid-mountain ranges. Altai(Belukha - 4506 m) and Saiyan(mountain Munku-Sardyk - 3491 m), mountain ranges and highlands of Tuva, Baikal and Transbaikalia. In Transbaikalia, the peaks reach the highest heights Stanovoy Upland(highest point - 3073 m). Through Stanovoy Ridge the mountains of southern Siberia are connected with the mountain structures of the eastern outskirts.

To the east of the Lena and up to the shores of the Pacific Ocean, there are medium-altitude ridges and highlands: Verkhoyansk(2389 m), ridge Chersky(Victory - 3003 m), Suntar Khayata(2959 m), Dzhugdzhur(1906 m), Yano-Oymyakonskoye, Kolyma, Chukchi, Koryak(mountain Ice - 2453 m). To the south, they pass into the low and medium-altitude ridges of the Amur Region, Primorye (Sikhote-Alin) and Sakhalin, the maximum heights of which do not reach 2500 m. The eastern outpost is represented by the folded and volcanic mountains of Kamchatka and the Kuriles. Kamchatka is the highest point of the Asian territory of Russia - an active volcano Klyuchevskaya Sopka(4688 m). All the most high peaks Kamchatka and the Kuriles are active or extinct volcanoes.

The territory of Russia is characterized by the predominance of low and medium-altitude mountains. Mountains over 1500 m high occupy less than 10% of the country's area.

Thus, the eastern and southeastern outskirts of Russia are represented by mountain structures. In the southwest, near the southern border of the East European Plain, the lonely Caucasus rises.

Tectonic structure and history of development. To understand the regularities of the distribution of mountains and plains on the territory of the country, it is enough to look at the position of the territory in relation to the large lithospheric plates of our planet. Most of the territory of Russia is located within the Eurasian Plate - one of the largest lithospheric plates (see Fig. 4).

Rice. 4. Map of the boundaries of lithospheric plates Northern Eurasia

The East European and West Siberian Plains are located in its central part, and the Central Siberian Plateau is closer to the eastern outskirts. Mountains are located along the edges of the plate. Where the state border of Russia runs in the inner parts of the plate (western border, most of the border with Kazakhstan), there are no border mountains. In the same place where its boundaries approach the boundaries of the plate (Caucasus, Altai and further to the south- western outskirts Baikal), mountains are placed.

In the east, the Eurasian Plate is bordered geologically by the North American, Sea of ​​Okhotsk, and Amur plates, which have recently attached to it or are now breaking off. These three mesoplates separate the Eurasian plate proper from the Pacific one, with which it interacts. The mountainous structures of the eastern part of Russia are confined to this marginal part, which is part of the planetary compression zone. However, even here, along the strike of the ridges, one can clearly define the boundaries of the plates; for example, Dzhugdzhur, Sette-Daban, Suntar-Khayata, the ridges of Kamchatka and Sakhalin limit the Sea of ​​Okhotsk plate.

The current position of lithospheric plates, their structure, outlines and boundaries are the result of a long and complex geological development over hundreds of millions of years.

Let's compare the physical map with the tectonic one. The large plains of our country correspond to platforms, and mountain structures correspond to folded areas of various ages. As a matter of fact, there are no areas on the territory of Russia that would not undergo folding processes. In some places, folding ended long ago, in the Archean or Proterozoic. Such territories have existed since the beginning of the Paleozoic in the form of rigid, stable platforms, or cratons. In other places, folding proceeded much later, already in the Phanerozoic, in its various periods, in the third places it has not ended even now. These areas, according to the geosynclinal theory of the development of the earth's crust, are called geosynclines.

Geosyncline - a linear region of high mobility and permeability of the earth's crust. The geosyncline is characterized by a significant amplitude of the velocity and contrast of vertical and horizontal movements, strong magmatic activity, the predominance of subsidence and the accumulation of thick strata of marine, and sometimes partially continental sedimentary and volcanic rocks. From the standpoint of lithospheric plate tectonics, the geosyncline corresponds to the active margin of the continent (eugeosyncline) or its passive margin (miogeosyncline).

All continents at one time or another have gone through the stage of geosyncline in their development. Passed it and various territories of our country. At the final stage of geosyncline development, folding occurs, which is accompanied by vertical uplifts, the introduction of intrusions, and often an intense manifestation of volcanism (all this occurs during the collision of lithospheric plates). Mineralization and the formation of deposits of ore minerals are associated with magmatic processes. So, as a result of the completion of the development of geosynclines, folded areas(belts).

The most ancient folded areas were formed on the territory of Russia in the Archean and Proterozoic (2600-500 million years ago). They are composed of pre-Paleozoic rocks. It is they who form the lower structural tier of the platforms - their folded foundation.

Platforms - stable areas of the earth's crust, characterized by relatively little mobility. They are characterized by a weak division into areas of uplifts and subsidences, which are much smaller than in geosynclines, the amplitudes oscillatory movements, smaller and qualitatively different development of magmatic processes.

On the territory of Russia there are two ancient platforms - East European and Siberian. Both of them have a two-tier structure: a folded basement of crystalline and igneous rocks of the Archean-Proterozoic age and a Paleozoic-Cenozoic sedimentary cover. Sedimentary rocks of the cover lie quietly, usually subhorizontally. Sedimentation was interrupted during uplifts and was replaced by demolition processes.

East European Platform limited in the east by the Ural folded structures, in the south by the young Scythian plate, adjacent to the folded structures of the Caucasus, in the north continues under water Barents Sea, and in the west it extends far beyond the borders of Russia. Within it there are two shields, one of which - Baltic- enters the territory of the Kola Peninsula and Karelia, the second - Ukrainian - is completely outside of Russia. The rest of the platform space: occupies Russian stove .

The shallow foundation is typical for Voronezh anteclise(the first hundreds of meters) and some positive structures Volga-Ural vault. In syneclises ( Moscow, Pechora, Baltic) the foundation is lowered by 2-4 km. The greatest depth of the foundation is typical for Caspian syneclise(15-20 km).

Siberian platform is completely located within Russia and within its borders almost corresponds to the Central Siberian Plateau *. In its structure, it is in many respects similar to the East European. Its Archean-Proterozoic basement also forms an extensive shield ( Aldan) on the outskirts of the platform and much smaller ( Anabar), surrounded on all sides by a sedimentary cover. The rest of the platform is presented Lena-Yenisei plate with a sedimentary cover reaching its maximum thickness (8-12 km) in the deepest depressions of vast Tunguska and Vilyui syneclise. Approximately the same within both platforms and the average thickness of the earth's crust (35-45 km).

At the same time, the Siberian platform differs in many respects from the East European one. If the East European platform is a single isometric block, then the Siberian one consists of two unequal parts - the Angara-Anabar and Aldan, which, in all likelihood, were independent ancient platforms and were connected by a band of Baikal-Caledonian folding. In this case, the Siberian Platform as a single tectonic structure exists only from the Middle Paleozoic (E.E. Milanovsky, 1987).

Another significant difference is that platform trap magmatism manifested itself within the Siberian Platform in the Permo-Triassic. The formations of the trap formation, represented by thick lava covers, sheet and secant intrusions, compose the upper part of the section of the huge Tunguska syneclise and adjacent territories.

In the history of the Earth, there were epochs of folding, when the processes of folding proceeded especially vigorously and ended with the appearance of large folded regions at the site of geosynclines: Baikal, Caledonian (Salairian and Caledonian proper), Hercynian (Varisian), Mesozoic (Cimmerian and Laramian), Cenozoic (Alpine and Pacific ).

Baikal folding occurred in the Late Proterozoic - Lower Cambrian. The structures created by her partially became part of the foundation of the platforms, consolidating older blocks, and also adjoin the outskirts of the ancient platforms. They delineate the Siberian platform from the north, west and south (Taimyr-Severozemelskaya, Baikal-Vitim and Yenisei-East-Sayan regions). The Timan-Pechora-Barents Sea Region is located on the northeastern margin of the East European Platform. Apparently, at the same time, the Irtysh-Nadym block was formed, which occupies a central position within the West Siberian Plain. Areas of Baikal folding E.E. Milanovsky (1983, 1987) refers to metaplatform areas .

In the Phanerozoic, along with ancient platforms and adjacent metaplatform areas, there are so-called mobile belts, three of which enter the territory of Russia: the Ural-Mongolian, Pacific and Mediterranean. In their development, mobile belts go through two main stages: geosynclinal and postgeosynclinal, or epigeosynclinal folded belt, the change of which in different belts and even in different areas of a single belt occurred at different times and dragged on until the end of the Phanerozoic.

The features of the first stage have already been discussed in the characterization of geosynclines. The tectonic regime of the second stage is significantly inferior in its activity to the geosynclinal one, but at the same time surpasses the tectonic regime of the ancient platforms.

Paleozoic Ural-Mongolian belt located between the ancient East European and Siberian platforms and forms the southern frame of the latter**. Downturns within this belt began as early as the Late Proterozoic, and in the Lower Paleozoic, a Caledonian folding. The main phases of folding occur at the end of the Cambrian - the beginning of the Ordovician (Salair), the middle - the Upper Ordovician, the end of the Silurian - the beginning of the Devonian. As a result of the Caledonian folding, mountain structures were created in the Western Sayan, Kuznetsk Alatau, Salair, in the eastern regions of Altai, in Tuva, in a significant part of Transbaikalia, in the southern regions of Western Siberia, adjoining in the western part of the Kazakh upland, where the Caledonian folding was also final. In all these territories, the Lower Paleozoic deposits are intensely folded and metamorphosed. A Precambrian base often peeps through their cover.

In the Upper Paleozoic (Late Devonian - Early Carboniferous and Late Carboniferous - Permian) hercynian(Varisian) folding. She was the final vast space Western Siberia, having consolidated the previously existing blocks here, in the Ural-Novaya Zemlya region, in western regions Altai, in the Tom-Kolyvan zone. It also appeared in the Mongolian-Okhotsk zone.

Thus, by the end of the Paleozoic, an intracontinental folding zone formed within the Ural-Mongolian mobile belt, soldering two ancient platforms into a single large structure, a rigid block that became the core of the Eurasian lithospheric plate. There was also an increase in the platform area due to the appearance of folded structures along their southern margins.

Later (in the Mesozoic), within the Ural-Mongolian belt, young epipaleozoic plates (quasicratons), including West Siberian, almost entirely located in Russia. They are confined to areas that experienced a general subsidence in the Meso-Cenozoic.

Plates usually form above those areas of mobile belts, in the structural plan of which blocks of ancient consolidation play a significant role - the median massifs. Young slabs do not always fit strictly into the contours of the movable belt. They can also be superimposed on areas of ancient platforms adjacent to the mobile belt (metaplatform areas), as is the case on the eastern margin of the West Siberian Plate. The cover of young platforms is composed of sedimentary sequences of the Meso-Cenozoic age. The thickness of the cover ranges from several hundred meters - a kilometer in the marginal parts to 8-12 km in the most deeply subsided northern part of the West Siberian plate.

Pacific mobile belt occupies a marginal position between the ancient Siberian Platform and the oceanic lithospheric plate of the Pacific Ocean (see Fig. 5). It includes folded structures of the North-East and the Far East.

Rice. 5. The main tectonic structures of Russia (according to V.M. Muratov)

Designations in Figure 5: I - ancient platforms (a - shields, b - plates); II - Ural-Mongolian belt (c - Baikalides, d - Salairides, e - Caledonides, e - Hercynides, g - marginal troughs, h - young plates); III - Mediterranean belt (i - alpine folded areas, k - foredeeps, l - young slabs); IV - Pacific belt (m - Mesozoic folded areas, n - middle massifs, o - marginal foredeeps, n - Laramian folded areas, p - marginal volcanic belt, s - Cenozoic folded areas). Numbers on the map: I - ancient platforms. East European platform - 1 - Baltic shield, 2 - Russian plate; Siberian platform - 3 - Anabar shield, 4 - Aldan shield, 5 - Taimyr shield, 6 - Central Siberian plate. II - Ural-Mongolian belt. Baikal folded areas - 7 - Baikal-Patom, 8 - Sayano-Yenisei; Salair folded areas - 9 - Barguzino-Vitim, 10 - East Sayan, Tuva, Kuznetsk-Alatau; Caledonian folded areas - 11 - West Sayan and Gorno-Altai; Hercynian folded regions - 12 - Ural, 13 - Tom-Kolyvan and Salair, 14 - Mongolian-Okhotsk; Hercynian marginal troughs - 15 - Cis-Ural, 16 - Kuznetsk; young plates - 17 - West Siberian, 18 - Timan-Pechora, III - Mediterranean belt. Alpine folded structures - 19 - Caucasus; marginal foredeeps - 20 - Indolo-Kuban, 21 - Terek-Caspian; young plates - 22 - Scythian. IV - Pacific belt. Mesozoic folded areas - 23 - Verkhoyansk-Chukotka folded system; middle massifs - 24 - Kolyma, 25 - Smolensk, 26 - Okhotsk, 27 - Chukchi-Yukon; Mesozoic marginal foredeep - 28 - Predverkhoyansky; Laramian folded areas - 29 - Sikhote-Alin folded system, 30 - Koryak; marginal volcanic belt - 31 - Okhotsk-Chukotsky, 32 - Sikhote-Alin; Cenozoic folded region - 33 - Kamchatka-Olutorskaya, 34 - Sakhalin, 35 - Kuril Islands, 36 - Commander Islands

Some sections of this belt completed the period of geosynclinal development as early as the Precambrian or Paleozoic and form median massifs, the largest of which are Kolyma and Bureinsky(peculiar "microplatforms" with a shield and a plate); others experienced folding in the Mesozoic, others in the Cenozoic.

Verkhoyansk-Chukotka folded region created Cimmerian folding(late Cimmerian, or Kolyma, end of the Jurassic - middle of the chalk). The Okhotsk-Chukotka volcanic belt stretches along the southeastern margin of this region, which passes into the Primorsky volcanic belt in the southern part of the Far East, separating the mesozoids of this region from the region of Pacific folding. Early and late Cimmerian folding appeared here, which created the Mesozoic structures of the Amur region and the central part of the Sikhote-Alin, and the Larami searched (late Cretaceous - early Paleogene), culminating in the formation of folded structures in Sikhote-Alin. The Koryak region was also created by the Laramian folding.

The mountain structures of Sakhalin and Kamchatka arose as a result of Pacific folding, which manifested itself in the Oligocene and mainly in the Neogene-Quaternary time, i.e. are at the orogenic stage of development. These are the youngest folded and volcanic mountains in Russia. The Kuril Islands have not yet completed their geosynclinal development; these are modern island arcs with a deep-water trench located next to it, clearly fixing the subduction zone of the Pacific lithospheric plate. Vast areas here are occupied by the oceanic crust. Actually, the island arcs are characterized by the early stages of the formation of the continental crust.

The ongoing tectonic activity, especially along the eastern margin of this belt, is evidenced by intense volcanic activity, a large amplitude of Quaternary uplifts, and a high seismicity of the region.

Mediterranean mobile belt stretched along the southwestern margin of the Eurasian plate. Like the Ural-Mongolian belt during its geosynclinal development, it occupied an interplatform position, and in the postgeosynclinal period, it occupied an intracontinental and partly intercontinental position. It was formed during the convergence of the Eurasian plate with the African-Arabian and Indo-Australian plates. It approaches the borders of Russia only in the region of the Greater Caucasus.

This belt was laid down in the Riphean. Its various parts (segments) completed the geosynclinal development in different times. The central part, which includes the Caucasus, closed at the end of the Pliocene and belongs to the Alpine folded region. At the same time, the Caucasus is the most typical link in the Alpine folded structures.

The outer zone of this belt is represented by Scythian plate, the folded base of which was created by the Hercynian folding and in the marginal troughs is lowered by 6-8 km (up to a maximum of 12 km), and the inner - folded region of the Caucasus. The Greater Caucasus belongs to the outer anticlinoria of the Alpine-Himalayan folded region. Under it there is a "granite root" of mountains with a thickness of the earth's crust up to 60 km (M.N. Smirnova, 1984). Within the belt, both Early Cimmerian and Laramian folding occurred, but the Cenozoic folding in the Pliocene was the final one.

Although the formation of the folded belt has been completed here, the territory still retains significant mobility.

The presence of high ridges and the Transcaucasian intermountain depressions, earthquakes, and volcanic events in the recent past testify to the ongoing orogenic development. continental crust formed over a long geological time and, probably, its formation has not yet been completed.

The relationship of minerals with the geological structure and tectonics. Minerals reveal an even closer connection than the relief with the history of the geological development of the territory. Ore minerals were formed from magma that penetrated into the earth's crust as a result of its differentiation. Magmatic activity is most actively manifested in geosynclines at the final stage of their development; therefore, ore minerals are confined to folded areas.

Features of the geological development of a particular folded belt and its individual parts are reflected in the richness of minerals and their diversity. Where magmatic activity manifested itself already in the early stages of the development of the mobile belt (intense subsidence and formation of island arcs), basic and ultrabasic igneous rocks predominate. They are associated with copper-pyrite, copper-nickel, chromium and titanomagnetite ores, deposits of cobalt and platinum. At the final, orogenic stage, granitoid magmatism develops. Granite magma in different areas is geochemically heterogeneous, therefore, in some cases, this magmatism is associated polymetallic mineralization (lead-zinc ores), gold, silver, other - rare metal(tungsten-molybdenum, tin, tungsten ores, etc.). Mercury-ore belts are connected with deep faults.

The more actively magmatic activity manifested itself within the mobile belt, the richer it is in minerals. The more varied the composition of the magma, the more diverse the set of minerals. The folded regions of the Ural-Mongolian mobile belt are richest in various minerals, the Urals stand out in particular. The metallogeny of the Pacific belt is characterized by the predominance of tin, tungsten, and gold. In the Caucasus, which is part of the Mediterranean belt, there are deposits of copper-zinc and tungsten-molybdenum ores.

Within the platforms, ore minerals are confined to a folded base, which in most of them is buried under a thick sedimentary cover. Only on shields and massifs, as well as within some anteclises, iron ores and gold are mined associated with the Archean-Proterozoic and Baikal folded structures (Aldan shield, Yenisei massif, Voronezh anteclise, Baltic shield).

The main minerals of the platforms are associated with their sedimentary cover. First of all, these are fossil fuels. At the bottom of the seas, lakes and swamps, organic residues accumulated, which later turned into extensive oil and gas fields. gas fields, deposits of hard and brown coal, oil shale. All platforms have these deposits, but the Siberian platform stands out primarily for its coal reserves, and the young West Siberian plate for oil and gas. Rock and potash salts, phosphorites, bauxites, bean iron ores, and cuprous sandstones are also associated with the sedimentary cover.

There are certain regularities in the placement of certain minerals in the strata of the sedimentary cover, depending on the tectonic and climatic conditions in which these strata accumulated. During the period of marine transgressions, deposits of sedimentary iron, manganese ores and phosphorites were formed, with a stable position of the sea, sandy-argillaceous strata rich in organic matter (from which oil and gas deposits subsequently arose), flasks or limestones accumulated; during regressions, salts and cupriferous sandstones accumulated in the lagoons of the arid regions, and coals accumulated on the swampy coasts in humid conditions.

For individual geological periods its own combinations of conditions that are most favorable for the formation of one or another mineral or their group are characteristic: redox conditions, hot or cold, dry or humid climate, the predominance of certain groups of organisms, etc. Thus, coal deposits are associated with carbon deposits, salt deposits with Permian deposits, brown coal, oil and gas deposits with Cretaceous deposits, and manganese deposits with Oligocene deposits.

In folded areas, minerals confined to the sedimentary cover are found only in marginal troughs and in the cover of intermountain depressions.

variety of geological structure and huge size the territory of Russia determined the presence in our country of a wide variety of minerals. In terms of the reserves of many of them, our Motherland occupies one of the leading places in the world. Yes, on the corner natural gas, iron ores, rock salts, Russia ranks first, in oil - second (after Saudi Arabia), etc. In general, Russia has huge reserves of almost all types of minerals and can provide for all industries related to the use of mineral raw materials.

Recent tectonic movements and their role in the formation of modern relief

As a result of a long history of geological development on the territory of Russia, the main types of geotectures have formed - flat-platform areas and large orogenic mobile belts. However, within the same geotectures, completely different relief is often distributed (the low basement plains of Karelia and the Aldan Highlands on the shields of ancient platforms; the low Ural Mountains and the high mountain Altai within the Ural-Mongolian belt, etc.); on the contrary, a similar relief can form within different geotectures (the high mountains of the Caucasus and Altai). This is due great influence on the modern relief of neotectonic movements that began in the Oligocene (Upper Paleogene) and continue to the present.

After a period of relative tectonic calm at the beginning of the Cenozoic, when low plains prevailed and mountains were practically not preserved (only in the area of ​​Mesozoic folding, in some places, apparently, low hills and low mountains were preserved), vast areas of Western Siberia and the south of the East European Plain were covered with waters. shallow sea basins. began in the Oligocene new period tectonic activation - neotectonic stage, which led to a radical restructuring of the relief.

Recent tectonic movements and morphostructures. Neotectonics, or latest tectonic movements, V.A. Obruchev defined as movements of the earth's crust that created the modern relief. It is with the latest (Neogene-Quaternary) movements that the formation and distribution of morphostructures across the territory of Russia are associated - large landforms that arose as a result of the interaction of endogenous and exogenous processes with the leading role of the former.

The latest tectonic movements are associated with the interaction of modern lithospheric plates (see Fig. 6), along the margins of which they manifested themselves most actively.

Rice. 6. The latest tectonic movements (according to N.N. Nikolaev)

The amplitude of Neogene-Quaternary movements in the marginal parts reached several kilometers (from 4-6 km in Transbaikalia and Kamchatka to 10-12 km in the Caucasus), and in the inner regions of the plates it was measured in tens, less often hundreds of meters. Sharply differentiated movements prevailed in the marginal parts: uplifts of large amplitude were replaced by equally grandiose subsidences of adjacent areas. In the central parts of the lithospheric plates, movements of the same sign occurred over large areas.

Mountains arose in the immediate contact zone of various lithospheric plates. All the mountains that currently exist on the territory of Russia are the product of the latest tectonic movements, i.e. all of them arose in the Neogene-Quaternary time and, therefore, have one age. But the morphostructures of these mountains are very different depending on the mode of their origin, and it is associated with the position of the mountains within the various tectonic structures.

Where mountains arose on the young oceanic or transitional crust of the marginal parts of the plates with a thick cover of sedimentary rocks crumpled into folds (areas of the Alpine and Pacific foldings), young folded mountains formed (the Greater Caucasus, the Sakhalin ridges) sometimes with areas of volcanic mountains (the ridges of Kamchatka ). The mountain ranges here are linearly extended along the margin of the plate. In those places where, at the boundaries of the lithospheric plate, there were territories that had already experienced folding movements and turned into plains on a folded base, with a rigid continental crust that could not be compressed into folds (areas of pre-Paleozoic and Paleozoic folding), the formation of mountains proceeded differently. Here, with lateral pressure arising from the approach of lithospheric plates, the rigid foundation was broken by deep faults into separate blocks (blocks), some of which were squeezed upwards during further movement, others - downwards. So mountains are reborn in place of the plains. These mountains are called revived blocky, or folded-blocky. All the mountains of the south of Siberia and the Urals are revived.

The revived mountains are characterized, as a rule, by the absence of a single general orientation of the ridges, a combination of mountain ranges with nodes from which ridges scatter in all directions (Altai), massifs, highlands (East Tuva, Stanovoye, Aldanskoye, etc.). An obligatory element of the revived mountains is the presence intermountain basins irregular outlines corresponding to the lowered blocks (Tuvinskaya, Minusinskaya, Kuznetskaya, Chuiskaya, Uimonskaya, etc.).

In the areas of Mesozoic folding, where by the time of the beginning of intensive movements the mountains could not be completely destroyed, where areas of low-mountain or low-hill terrain were preserved, the orographic pattern of the mountains could not change or change only partially, but the height of the mountains increased. Such mountains are called rejuvenated blocky-folded. They reveal the features of both folded and blocky mountains with a predominance of one or the other. The rejuvenated ones include the Sikhote-Alin, the mountains of the North-East and partly the Amur region.

The inner parts of the Eurasian lithospheric plate belong to the areas of weak and very weak uplifts and predominantly weak and moderate subsidence. Only the Caspian lowland and southern part Scythian plate. Most of the territory of Western Siberia experienced weak subsidence (up to 100 m), and only in the north were subsidence moderate (up to 300 m or more). The southern and western outskirts of Western Siberia and the greater eastern part of the East European Plain were a weakly mobile plain. The greatest amplitudes of uplifts on the East European Plain are characteristic of the Central Russian, Volga and Bugulmino-Belebeevskaya Uplands (100-200 m). On the Central Siberian Plateau, the amplitude of uplifts was greater. The Yenisei part of the plateau is raised by 300-500 m, and the Putorana plateau even by 500-1000 m and higher.

The result of the latest movements was the morphostructure of the platform plains. On the shields, which had a constant tendency to rise, basement plains (Karelia, Kola Peninsula), plateaus (Anabar massif) and ridges (Timan, Yenisei, eastern spurs of Donetsk) were formed - hills that have an elongated shape and formed by dislocated rocks of a folded base.

On the slabs, where the basement rocks are covered by a sedimentary cover, accumulative plains, stratal plains and plateaus have formed.

Accumulative plains are confined to areas of subsidence in recent times (see Figs. 6 and 7), as a result of which they have a fairly thick cover of Neogene-Quaternary deposits. The accumulative plains are the middle and northern parts of the West Siberian Plain, the Middle Amur Plain, the Caspian Lowland, and the north of the Pechora Lowland.

Rice. 7. Largest morphostructures

On fig. 7: Morphostructures of the land, the bottom of the oceans and seas. Land - 1 - plains, plateaus (a) and revived mountains (b) of ancient platforms (I - East European (Russian) plain, II - Kola-Karelian country, III - Central Siberian plateau, IV - Baikal mountainous country); 2 - plains of young platforms (V - West Siberian Plain, VI - Ciscaucasia); 3 - revived mountains of the Paleozoic folding region (VII - Ural, Novaya Zemlya, VIII - Altai-Sayan mountainous country); 4 - rejuvenated mountains of the Mesozoic folding region (IX - the mountainous country of the Northeast, X - the Amur-Primorsko-Sakhalin country); 5 - young mountains of the alpine folding region (XI - Caucasus); 6 - young mountains of the Cenozoic (Pacific) folding region (XII - Koryak-Kamchatka-Kuril country, XIII - Okhotsk-Primorsky volcanic belt). The bottom of the oceans and seas. Continental shelf - 7 - plains of the mainland outskirts; 8 - plains on intrashelf depressions, transitional zone (continental slopes and island arcs); 9 - inclined plains - ledges; 10 - plains of the bottom of the basins; 11 - fold-block ridges and massifs, 12 - fold-block and volcanic ridges of island arcs, 13 - deep-water trenches. The bed of the oceans and seas - 14 - the plain of the bottom of deep-water basins, 15 - mid-ocean ridges, 16 - shaft and uplands, 17 - fold-block ridges

Layered plains and plateaus are morphostructures of plate sections that have experienced predominant uplifts. With a monoclinal occurrence of rocks of the sedimentary cover, inclined layered plains predominate, with a subhorizontal - layered-stage plains and plateaus. Layered plains are characteristic of most of the East European Plain, the southern and western outskirts of Western Siberia, and partly of Central Siberia. On the territory of Central Siberia, plateaus are widely represented as sedimentary(structural - Angara-Lena, Leno-Aldan, etc.), and volcanic(Putorana, Central Tunguska, Siverma, etc.).

Volcanic plateaus are also characteristic of mountainous regions (the Eastern Sayan, the Vitim Plateau, the Eastern Range in Kamchatka, etc.). Shield morphostructures can also be found in the mountains, and accumulative and, to a lesser extent, stratified plains (Kuznetsk Basin) can be found in intermountain basins.

Earthquakes and modern volcanism. In close connection with the latest tectonic movements are earthquakes and modern volcanic phenomena. Frequent and strong (up to 9 points or more) earthquakes occur in the Kuriles, in the southeastern part of Kamchatka, in the Baikal region (from the Verkhnecharskaya basin to the Tunkinsky graben), in the eastern and southwestern parts of Tuva and in the southeastern part of Altai. In the region of the Greater Caucasus, near the Lena delta and in the region of the Chersky ridge in the North-East, there are earthquakes with a magnitude of up to 7-8 points.

Comparison of the seismic zoning map with the map of lithospheric plates shows that all seismic regions of Russia are part of four seismicity belts coinciding with the boundaries of lithospheric plates. They pass:

· 1) along deep-water trenches framing the Kuril-Kamchatka arc, where the Pacific plate approaches the Eurasian one at a rate of 8 cm/year;

2) from the Gakkel Ridge in the Arctic Ocean through the Chersky Ridge, where the Chukchi-Alaska block of the North American Plate broke away from the Eurasian Plate and is moving away at a rate of 1 cm/year;

· 3) in the area of ​​the basin of Lake Baikal, the Amur plate broke away from the Eurasian plate, which rotates counterclockwise and moves away at a speed of 1-2 mm/year in the Baikal area. For 30 million years, a deep gap arose here, within which the lake is located;

· 4) in the region of the Caucasus, which falls into the seismic belt stretching along the southwestern margin of the Eurasian plate, where it approaches the African-Arabian plate at a rate of 2-4 cm/year.

Earthquakes testify to the existence of deep tectonic stresses in these areas, which are expressed from time to time in the form of powerful earthquakes and ground vibrations. The last catastrophic earthquake in Russia was the earthquake in the north of Sakhalin in 1995, when the city of Neftegorsk was wiped off the face of the earth.

In the Far East, there are also underwater earthquakes, accompanied by seaquakes and giant destructive tsunami waves.

Platform sections with their flat relief, with weak manifestations of neotectonic movements do not experience significant earthquakes. Earthquakes are extremely rare here and manifest themselves in the form of weak vibrations. So, the earthquake of 1977 is still remembered by many Muscovites. Then the echo of the Carpathian earthquake reached Moscow. In Moscow, on the 6th-10th floors, chandeliers swayed and bunches of keys rang in the doors. The magnitude of this earthquake was 3-4 points.

Not only earthquakes, but also volcanic activity is evidence of the tectonic activity of the territory. Currently, volcanic phenomena in Russia are observed only in Kamchatka and the Kuril Islands.

The Kuril Islands are volcanic ranges, highlands and solitary volcanoes. In total, there are 160 volcanoes in the Kuril Islands, of which about 40 are currently active. The highest of them is Alaid volcano (2339) on Atlasov Island. In Kamchatka, volcanism gravitates towards the eastern coast of the peninsula, from Cape Lopatka to 56°N, where the northernmost volcano is located. Shiveluch .

The high (up to 500-1000 m above sea level) volcanic plateaus located here serve as a pedestal for volcanic cones located in groups. In total, there are 28 active volcanoes in Kamchatka and about 130 extinct ones. Volcanoes shaped like regular truncated cones predominate. The highest and most beautiful active volcano in Russia - Key Hill, the snow-covered peak of which rises to 4688 m.

At the beginning of the Quaternary period, volcanism in Kamchatka manifested itself much more widely and more actively, as evidenced by the spread of extensive lava plateaus here. Young Quaternary volcanoes are known in the Anyui Ridge and the Chersky Ridge (North-East). Active volcanoes in the Quaternary were Elbrus and Kazbek. Fresh traces of volcanic activity are very numerous in the Sikhote-Alin; Eastern Sayan and the East Tuva Highlands.

The most important events of the Quaternary period and their reflection in modern relief

The duration of the Quaternary period is short, only about 2 million years, but geological history, the events of this most recent period were most reflected in modern look nature. The most important events of the Quaternary period, along with neotectonic movements, include ancient glaciations and marine transgressions, which had direct influence on morphosculptures.

Ancient glaciations. The glacial theory is over 150 years old. In 1939, a monograph by I.P. Gerasimov and K.K. Markov "Ice Age on the territory of the USSR". Since then, a lot of new factual material has accumulated, some ideas about ancient glaciation have been revised, in particular, for some time the idea of ​​​​four- and even five-fold glaciation in the Quaternary period was approved (Aseev A.A., Voznyachuk L.N., Goretsky T .I., Moskvitin A.I., Serebryanny L.R. and others), but, in the end, it turned out that the main provisions of the named monograph have retained their significance to this day.

It has been established that long, lasting tens of millions of years, cold stages in the development of the Earth occurred repeatedly in the geological past. They are called ice ages. Last, Quaternary Ice Age it would be more correct to call Late Cenozoic, since in the southern hemisphere it began over 30 million years ago, in the northern hemisphere large ice sheets appeared only about 2.5 million years ago.

The repeated glaciations were caused by rhythmic climate changes, alternating warm and cold, wet and dry conditions. Over the past 900 thousand years, nine global coolings and glaciations and the same number of warmings are known. Consequently, the duration of one cycle (cooling-warming) is about 100 thousand years, of which only about 10% of the time fell on periods of warming, the rest - to the cold part of the cycle. At present time runs the Holocene interglacial, which began about 10 thousand years ago.

Glaciers were of great relief-forming importance. They covered over 20% of the territory of Russia. In a wide strip near the edge of the glaciers, melt waters played a leading role in the formation of the relief.

At present, most scientists believe that traces of three glacial epochs in the Pleistocene can be traced on the territory of Russia: Mindel (or Oka) - early Pleistocene; rice (Dnieper with the Moscow stage) - middle Pleistocene; Würm (Valdai) - late Pleistocene (see Fig. 8).

Rice. 8. Ancient glaciations (according to the Atlas of the USSR, 1983)

The largest in area coverage was the maximum Dnieper(in Siberia - Samarovskoe) glaciation. Its border within Russia runs along the western outskirts of the Central Russian Upland from the city of Sumy to Bryansk-Mtsensk, in the Tula region it crosses the upland, then the language descends from the Oka-Don Lowland to Yelets-Rossosh, to the mouth of Khopra and Medveditsa *, then the border goes to Penza - Saransk, crosses the Volga near the mouth of the Sura, to Kotelnich - Kirov - along the Cheptsa River - south of the city of Glazov to the Chusovaya River. Crossing the Urals near 58° N, the glaciation boundary goes through the upper reaches of the Tura and Tavda rivers, crosses the Irtysh north of the river Demyanka, in the area of ​​the mouth of the Vakha, crosses the Ob, then along the interfluve of the Vakha and Tym to the mouth of the Podkamennaya Tunguska, further to the upper reaches of the Vilyui and Olenyok rivers. The glaciers of the Moscow stage occupied a smaller area than the glaciers of the Dnieper glaciation.

As for the Early Pleistocene glaciation, occupying a smaller area than the Dnieper, it is actually not expressed in the modern relief and is detected mainly by the presence of a moraine lying under the Dnieper.

Despite the fact that the strongest wave of cold, according to A.A. Velichko (1968), falls on the second half of the late Pleistocene (Valdai glaciation), the glacier on land occupied a much smaller area at that time. The reason for this was the great glaciation of the ocean, when oceanic ice reached the middle latitudes, so a powerful cooling was accompanied by a drying up of the climate, which did not contribute to the development of such significant continental glaciation as in the middle Pleistocene.

Border Valdai glaciation passed along the line Smolensk - Ostashkov - Rybinsk Reservoir - Lake Kubenskoye - the city of Velsk - Verkhnyaya Toima (on the North Dvina) - along the western and northwestern outskirts of the Dvina-Mezen Upland to the Tsilma River in the area where it crosses the Timan Ridge, then to the sublatitudinal the segment of the Pechora, to Salekhard, to the lower reaches of the Nadym, Pura and Taz, to the mouth of the Lower Tunguska, along the middle reaches of the Kotui River, to the lower reaches of the Anabar and the eastern coast of Taimyr (Spiridonov A.I., 1974).

In the glacial epochs south of the glacier boundary, deep freezing of soils occurred. During the Valdai glaciation, the border permafrost shifted as never before far to the south, to the lower reaches of the Don - Volgograd.

Approximately 10 thousand years ago, warming began, marking the end of the Pleistocene and the transition to the Holocene epoch. The ice sheets on the plains and glaciers in the mountains were greatly reduced, the border of oceanic ice shifted far to the north, and with it the border of permafrost on land moved away, especially in the western part of the country (west of the Yenisei).

Relief forms created by ancient glaciers and flows of melted glacial waters occupy the second place among morphosculptures in Russia after fluvial (erosion-accumulative forms). The glacial forms of the mountainous and lowland regions are very different. Modern differences in the ancient glacial relief are associated with its uneven age and the resulting unequal duration of its processing by subsequent slope, fluvial and other processes.

Fresh forms of ancient glacial relief are characteristic of the region of the Valdai (in Siberia - Zyryansk) glaciation.

Forms of glacial exaration have been preserved within the Scandinavian, Ural-Novaya Zemlya, Taimyr and Putorana centers of glaciation. On the Kola Peninsula and in Karelia, for example, such forms as lamb foreheads and curly rocks(clusters of small mutton foreheads).

The northwest and north of the East European Plain, the north of Western Siberia, the North Siberian Lowland, the part of the Central Siberian Plateau adjacent to the Putorana Plateau are distinguished by a pronounced glacial-accumulative relief. Randomly scattered moraine hills with depressions between them, occupied by lakes or marshy ( lakeside). Among them are common drumlins- elongated hills, elongated along the movement of the glacier and having a core of bedrock, covered by moraine. Here they meet ozes- long narrow shafts, resembling a railway embankment, crossing various elements relief. They are composed of sand-gravel-pebble material and represent deposits of rivers flowing inside the glacier body or on its surface. Ozes are genetically linked kamy- hills of irregular shape, composed of layered sandy-loamy or sandy-gravel material of glacial, subglacial or intraglacial reservoirs (lakes). In the marginal strip are common terminal moraine ridges, fixing stops in the movement of the glacier.

Particularly characteristic are clear glacier-accumulative landforms for the northwest of the East European Plain. In Western Siberia, they are less pronounced and do not have such a wide distribution, possibly due to the development of marine transgressions here in the Ice Age and the formation of glacial-marine landforms and sediments (Popov A.I., Meshcheryakov Yu.A., etc.) . Within the Central Siberian Plateau, forms of glacial exaration predominate, and the glacial-accumulative relief is much less pronounced due to the weak mobility of less powerful ice sheets.

To the south of the band of ridge-hilly relief, which marks the boundary of the Late Pleistocene glaciation, the nature of the morphosculpture changes. It is dominated by wavy or flat secondary moraine plains with separate areas of smoothed hilly relief. The hilly-morainic relief created by the Moscow (Taz in Siberia) glacier underwent significant processing during the Valdai glaciation and post-glacial period. There was a smoothing of the hills, the filling of the inter-moraine basins with material carried down from the slopes, which generally led to a smoothing of the relief. This is how the secondary moraine plains arose. Planar washout and solifluction were the main factors of relief processing. In the subsequent dissection of the surface, the processes of linear erosion begin to play an increasingly important role.

The relief in the area of ​​maximum (Dnieper, in Siberia Samarovo) glaciation has been reworked even more strongly. The ancient glacial morphosculpture here has been subjected to such a long processing, mainly by erosion processes, that the surface almost everywhere has acquired the character of moraine-erosion and erosion plains.

In the development of the relief of the areas of ancient glaciations, melted glacial waters and near-glacial reservoirs, their erosive-accumulative and abrasion activity, played an important role. Where the glacier, in the process of its movement to the south, reached extensive depressions, which ensured the outflow of melt water from its body, extensive outwash (fluvioglacial) plains formed at the edge of the glacier. Where the runoff was impeded, near-glacial reservoirs or detours of melt water flow arose, which gradually united into large erosional depressions that inherited buried river valleys.

The severe climatic conditions of the periglacial regions favored the development of eolian processes. As a result of eolian processing of the sandy material of outwash plains, parabolic dunes, longitudinal and transverse ridges.

Outland fields occupy especially large areas near the boundaries of the Moscow (Taz) stage of the Middle Pleistocene glaciation. The most extensive periglacial reservoir existed in the Middle Pleistocene near the glacier boundaries in Western Siberia, where, with a general slope of the surface to the north, the flow of melted glacial waters in this direction was restrained by the glacier located here.

Mountains subjected to glaciation are characterized by sharp forms the so-called alpine relief. The ridges of the mountains are jagged, the peaks are peaked, the slopes are complicated by ancient glacial circuses and karami, on the bottoms of which lakes are often found. The location of the cars indicates the position of the snow border in the mountains during the glaciation period. Large valley glaciers descended below this boundary, forming U-shaped trough valleys. This type of relief is formed when mountain-valley glaciation. In the mountains where there is modern glaciation, its formation continues.

In the mountains of the Northeast and the revived mountains of Southern Siberia (Altai, Sayan, Baikal), earlier glaciation was semi-integumentary. The glacier lay in the form of a continuous cover on leveled surfaces and descended the slopes in short, wide lobes.

The features of ancient glaciation in various mountainous regions were determined not only by the general climatic situation, but also by the height of the mountains at the time of glaciation compared to the height of the snow boundary in a given area. For example, Yu.P. Baranov (1967) pointed out that in the mountains of the Northeast, the early Pleistocene cooling did not cause glaciation, since only individual mountain peaks slightly rose above the snow line.

Cryogenic morphosculpture. In glacial epochs, on vast areas devoid of ice cover, as already noted, deep freezing of soils and the formation of permafrost and the formation of cryogenic morphosculpture associated with it took place. Now cryogenic morphosculpture is widespread where modern climatic conditions contribute to the preservation of permafrost, and in the northern regions of Siberia and its formation.

In the western part of Russia, cryogenic morphosculpture is distributed in a relatively narrow strip along the coast of the seas of the Arctic Ocean, mainly within the tundra and forest tundra, but beyond the Yenisei it is found up to the southern borders of our country.

On the plains, the distribution of thermokarst depressions and heaving mounds is associated with permafrost. Thermokarst basins - rounded regular shapes arising from the melting of underground ice. In diameter, they have from several tens of meters to 1-2 km; sometimes merge into a chain of basins. positive forms cryogenic relief are annual heaving bumps and perennial mounds - bulgunnyakhi(hydrolaccoliths), reaching 30-40 m in height and 100-150 m in diameter. All these forms are formed in areas with a fairly thick cover of loose sediments and significant ground ice content. They are especially characteristic of Central Yakutia, the Kolyma and Yano-Indigirka lowlands, the North Siberian lowland and northern regions Western Siberia. In areas with a thin cover of loose deposits (numerous plateaus of Central Siberia), solifluction processes and the processes created by them are most common. solifluction terraces. common in the tundra polygonal formations (spots-medallions, stone polygons) and thermokarst depressions. The dimensions of the polygons range from 1-2 to 15-20 m, sometimes reaching 50-60 m. Ice plays a significant relief-forming role in areas of permafrost. Especially large icings - taryns - are characteristic of the North-East, where subpermafrost ices rising along the faults take part in their formation. The groundwater.

In the mountains, as a result of cryogenic relief formation, bald surfaces are formed, which have smoothed outlines and are covered with polygonal soils. They are characterized kurums- placers of stone fragments, covering peaks and gentle slopes like a mantle ( stone seas). With an increase in the slope of the surface, the clastic material under the action of gravity begins to slowly move down, examining the stone rivers. Characteristic for loaches upland terraces descending in steps down the slopes of mountains. The width of the terrace areas is from several meters to 1-2 km, the height of the ledges is from 1-2 to 10-20 m.

I.P. Gerasimov noted that the main stage in the formation of the mass of rubble-stony material of the loaches falls on the ice age, although this process continues today.

The golts relief is distributed above the forest line in all the mountainous regions of Siberia and the Far East, which are deprived of modern glaciation, as well as in the Northern, Subpolar and Polar Urals.

Fluvial morphosculpture. Huge areas of our country are covered by fluvial morphosculpture. water streams of various sizes were the main factor of exogenous relief formation in almost half of the territory of Russia. However, their activity in different regions is different, as is the combination with other processes of relief formation.

river valleys- most large forms fluvial morphosculpture - distributed throughout Russia. Many of them already existed by the beginning of the Pleistocene. Ravine-beam relief most typical of non-glacial areas, especially for the highlands of the southern part of the country. However, erosion processes and, accordingly, fluvial morphosculpture also cover the areas of distribution of ancient glacial morphosculpture. Fluvial morphosculptures are especially widely represented in the mountains.

The intensity of the development of fluvial processes during the Quaternary time was influenced, in addition to various climate changes and related glaciations, also by the latest movements (they intensified during and in places of uplifts) and fluctuations in the level of the seas - the main bases of erosion.

Marine transgressions. major events Quaternary time there were sea transgressions. On the coast of the Arctic Ocean there are marine deposits of the so-called boreal transgression that preceded the late Pleistocene glaciation. The sea flooded the most low areas of the north of the East European and West Siberian plains, Taimyr and the North Siberian lowland and penetrated inland along the valley depressions of large rivers. During the boreal marine transgression, the Baltic Sea had a connection with the White Sea, as evidenced by the marine deposits of Karelia, and through it - with the Arctic Ocean.

In the Holocene, a marine transgression also took place, the deposits of which are distributed in the coastal areas of the Pechora Lowland, Yamal, the Gydan Peninsula, and the northern archipelagos. A narrow strip of marine and lacustrine sediments also exists along the shores of the Baltic Sea; they are left by the sea and lake basins that existed in its place in the post-glacial period (Joldian Sea - Lake Ancylus - Litorin Sea). In these territories, the relief of the primary sea plains is still poorly reworked.

The Pleistocene has several transgressions of the Black and Caspian Seas. In the early stages of the Pleistocene, the Black Sea had a wide connection with the Caspian Sea, but was isolated from the World Ocean. From the second half of the Middle Pleistocene, it received free communication with the Mediterranean Sea, and through it with the open ocean.

The Caspian lowland in the Pleistocene time was repeatedly flooded with the waters of the Caspian Sea (Baku, Khazar, Khvalyn transgressions). The waters of the Khvalyn Late Pleistocene transgression reached the Kamyshin latitude in the Caspian region. Less significant transgressions were observed in the Holocene. During the New Caspian transgression, the level of the Caspian Sea rose to a mark of 20 m. The relief of the bottom of the primary sea plain was well preserved in the lowland. This was facilitated by the arid climate and the low hypsometric position of the territory.

Other morphosculptures. Eolian landforms are not typical for Russia. Only in a small area of ​​the Caspian Sea they continue to develop at the present time. However, fixed dunes quite a lot on the boron terraces of rivers and sea shores. In Yakutia and on the Yamal Peninsula, areas with modern eolian relief are found in the taiga and even in the tundra.

Along with the ancient glacial, cryogenic, fluvial and arid morphosculpture associated with ancient or modern climatic zonality, on the territory of Russia there are types of morphosculpture, primarily due to the lithological features of the substrate: karst, suffusion-subsidence and landslide.

Karst forms (craters, ponors, disappearing rivers and streams, caves) are confined to areas of distribution of easily soluble, mainly carbonate rocks that come to the surface or occur at shallow depths. In addition to carbonate, karst rocks are also gypsum and easily soluble salts.

Karst forms are most widely developed on the territory of the East European Plain, in the Cis-Urals, in the mountains of the Urals and the Caucasus. In Central Siberia, where fairly large areas are occupied by Paleozoic carbonate rocks, the development of karst forms is limited by the spread of permafrost.

Suffosion-subsidence forms (steppe saucers, depressions, hearths), associated with the mechanical removal of fine particles by sediments seeping through the soil, are confined to poorly drained areas composed of loess and loess-like loams in the southern part of Western Siberia and the East European Plain.

The development of landslides is controlled by certain geological conditions occurrence of sandy-argillaceous deposits, the depth of dissection of the surface and sufficient moisture. They are most widely distributed in the middle zone of the East European Plain, especially in the Volga region.

Due to the fact that in the formation of morphosculptures essential role play modern exogenous relief-forming processes, in their distribution over the territory of Russia, zoning is quite clearly traced. It can also be traced in the speed and direction of processing of relic morphosculptures.

The superimposition of very different morphosculptures on different morphostructures, formed on the territory of Russia, creates big variety relief of our country.

RUSSIA (RUSSIAN FEDERATION, RF)- the largest country in the world in terms of area (17075.4 thousand km 2), a democratic federal state with a republican form of government.

The first mention of this country dates back to about the 10th century, in ancient Russian monuments of the 10th-15th centuries. these lands were called "Rus", "Russian land". In the 14th century they began to be called the Moscow principality, in the 15th century. - Moscow state or Muscovy, from the 16th century. - Russia.

In 1721 the state was officially named the Russian Empire.

Until 1917, Russia was understood as the totality of the territories of the Russian Empire, inhabited by both Russian and other peoples. After 1917 in connection with the establishment Soviet power the concept of "Soviet Russia" appeared, which could be called both Russia itself (and the RSFSR formed on its lands), and the entire Soviet Union formed in 1922.

After 1991 and the collapse of the USSR, "Russia" means the Russian Federation (proclaimed on June 12, 1990).

The Russian Federation. Moscow the capital. Population: 143.78 million (2004). The population density is 8.6 people per 1 sq. km. km. Urban population - 73%, rural - 27%. Area: 17,075.4 thousand square meters km. highest point: 5642 m above sea level (Elbrus). lowest point: 27 m below sea level (Caspian Sea). National language - Russian. Main religion: Orthodox Christianity. Administrative-territorial division: 21 autonomous republics, 49 regions, 6 territories, 10 autonomous districts, 1 autonomous region, cities of Moscow and St. Petersburg. Currency unit: 1 ruble = 100 kopecks.

Territory. The Russian Federation is located in the east of Europe and the north of Asia. The northernmost point on the mainland is Cape Chelyuskin (Taimyr Peninsula), on the islands - the north of Rudolf Island in the Franz Josef Land archipelago; the southernmost is in Dagestan, on the border with Azerbaijan; western - on the Baltic Spit in the Kaliningrad Bay; eastern - on about. Ratmanov in the Bering Strait.

Length land borders 22,125.3 km, they share Russia in the northwest with Norway, Finland, in the west - with Poland, Estonia, Latvia, Lithuania, Belarus. The southwestern border is with Ukraine, the southern border is with Georgia, Azerbaijan, Kazakhstan, China, Mongolia and the Democratic People's Republic of Korea.

The territory of Russia occupies 11 time zones.

Nature.

Relief. Most of Russia is located in a stable area of ​​the upper solid part of the earth's crust (lithosphere) of the Eurasian continent with a low-contrast, flat, plateau relief. According to the height and nature of the relief in the continental part of the territory of Russia, 6 large regions:

hilly-flat European part;

low-plain Western Siberia;

plateau-like and flat-mountainous Central Siberia;

mountains of Southern Siberia;

mountains and plains of the Northeast;

mountains and plains of the Far East.

The mountain systems of the Urals and the Caucasus, which are not part of them, delimit the European part and Western Siberia. One of the largest (more than 2 km) natural monuments, the karst Kapova Cave, is located in the Southern Urals, where in 1959 wall images of a mammoth, a horse, and a rhinoceros, the oldest for the Paleolithic, were discovered.

In the Lateral Range of the Greater Caucasus, there is the highest point of Russia and Europe, Mount Elbrus, a two-peak cone of an extinct volcano (the height of the western peak is 5642 m, the eastern peak is 5621) with 50 glaciers.

The Elbrus region with the Big and Small Azau, Irik, Terskol is one of the largest centers of mountaineering and skiing in Russia.

In the Sayans, in the Southern Urals, there are about 100 unique granite cliffs of bizarre shapes, incl. in the Stolby reserve in the Krasnoyarsk Territory - the highest (750 m.)

Water resources. The shores of Russia are washed by 12 seas belonging to the basins of 3 oceans - the Atlantic (Baltic, Black, Azov Seas), the Arctic (Barents, White, Kara, Laptev Sea, East Siberian, Chukchi), Pacific (Bering, Okhotsk, Japanese) and endorheic Caspian Sea. The length of Russia's maritime borders is 38,807.5 km. It also has maritime borders with the US and Japan.

The White Sea was mastered by the Russians as early as the 11th century. The oldest Russian settlement is Kholmogory, where the largest Russian scientist M.V. Lomonosov was born. From con. 15 to early 18th century the sea was of the utmost importance sea ​​route linking Russia with Western Europe. In the beginning. 18th century its transport role has decreased due to Russia's access to the Baltic. From the 20s of the 20th century. a significant part of Russia's maritime traffic is carried out through Murmansk, an ice-free port in the Barents Sea. A transport artery runs along the coast of the Arctic seas of Russia, connecting European and Far Eastern ports from Novaya Zemlya to the Bering Strait. The seas of the Pacific Ocean - Bering, Okhotsk and Japan - stretched along the Asian mainland. The beginning of the development of this region by Russia was laid in the middle. 17th century expeditions of I. Moskvitin and S. Dezhnev. Access to the Baltic Sea Russia secured victory in the Northern War of the early 18th century by annexing the coast with the ports of Revel (Tallinn), Narva, Riga, and Vyborg to its territory. From the first third of the 18th century Petersburg became the main foreign trade port, and Kronstadt became the main naval base.

The Black and Azov seas are inland, interconnected Kerch Strait, and the Bosporus and Dardanelles with the Mediterranean Sea and the Atlantic Ocean. The development of this water area by Russia dates back to the end of the 17th - beginning. 18th century

The world's largest drainless body of water is the Caspian Sea ("sea-lake"). The largest Russian river, the Volga, flows into the Caspian. The largest in Europe and the fifth longest in the world, it is connected by canals to the Baltic, White, Azov and Black Seas, as well as to the Moscow River, the main river of the Russian capital.

In terms of water flow resources, Russia ranks second in the world after Brazil with its most abundant river, the Amazon. In terms of one inhabitant, the availability of underground runoff resources, soil moisture, and total river runoff in Russia exceeds the world average by 4 times.

On the territory of Russia flows St. 2.5 million rivers The most abundant of them is the Yenisei (according to this indicator, Russia has the fifth place in the world). Most Russian rivers carry their waters to the Arctic and Pacific oceans.

Russia is a lake region, although there are few large lakes. The total number of Russian lakes exceeds 2.7 million, their area (excluding the Caspian) is more than 400 thousand square meters. km. In the Asian part of Russia , in the south of Eastern Siberia, in a tectonic depression in a reef system surrounded by mountain ranges, Lake Baikal is located, a UNESCO World Heritage Site. Lake Baikal ranks first in the world in terms of depth (1,620 m) and volume of fresh water (23,000 sq. km, which is 1/5 of the world's fresh water reserves). The area of ​​the lake is 31.5 thousand square meters. km, maximum length - 636 km, width - 48 km. The water level was raised by the dam of the Irkutsk hydroelectric power station by 0.8 m. There are 27 islands on the lake, 336 rivers flow into it and one river flows out - the Angara. The Bratsk reservoir on the Angara, formed in 1967 by the dam of the hydroelectric power station of the same name (area 5470 sq. km., volume 169.3 sq. km.) is used for navigation and water supply.

In the north-west of Russia lies the largest of the European freshwater lakes, Ladoga, (area - 17.7 thousand square kilometers, length 219 km, width 83 km, depth 230 m), it has 660 islands; 35 rivers flow into it, the Neva River flows out, on which at the beginning of the 18th century. St. Petersburg was erected, which was the capital of Russia for more than two centuries. In the 9th-12th centuries. the trade route “from the Varangians to the Greeks” (from the Baltic to the Black Sea) passed through Ladoga; from ser. 20th century Lake Ladoga is part of the Volga-Baltic and White Sea-Baltic waterways. (The Volga-Baltic waterway - the longest in Russia, about 1100 km - was built in the early 19th century, reconstructed in 1964). During the Great Patriotic War on ice Lake Ladoga The "Road of Life" was laid, which saved the inhabitants of Leningrad besieged by the Nazis from starvation.

The structure of water use is dominated by production needs. The main water problem in Russia is the pollution of rivers and reservoirs with waste from economic activities, which is why large water bodies in the country do not meet regulatory European requirements. According to the Water Legislation, 76% of fresh groundwater is used for domestic and drinking water supply, and 24% goes to the needs of industry and irrigation with a special permit from environmental authorities. However, only 30% of cities and towns in Russia are fully provided with underground drinking water. The water supply of Moscow, St. Petersburg and a number of other large cities is based on surface waters unprotected from pollution.

In addition to industrial, the waters of Russia are also used for medical and resort needs. Mineral underground waters (carbonic, rhodon, hydrogen sulfide, nitrogen, siliceous) feed over 300 deposits, including such well-known ones as Yessentuki, Pyatigorsk, Zheleznovodsk, Kislovodsk (Northern Caucasus), Marcipal waters (Karelia), Matsesta (Black Sea coast of the Caucasus), Belokurikha (in Altai).

Climate. Russia is a country with a relatively cold climate, winter temperatures are negative. Located in four climatic zones: arctic, subarctic (seas of the Arctic Ocean, arctic islands, northern mainland), temperate (most of the territory) and subtropical (a small section of the Black Sea coast of the Caucasus). Almost everywhere the climate is continental, the degree of continentality increases in the direction from west to east as the influence of the Atlantic Ocean weakens. In the same direction, cyclones bring the main precipitation. AT winter time continental air is very cold.

By climate indicators Russia is divided into a number of zones. (1) The Russian Arctic with a long sunny day (when the sun does not go below the horizon from early April to mid-September) and an equally long polar night(when the sun does not rise above the horizon from mid-October to the end of February). (2) European part Russia with a tangible influence of the Atlantic - here there is a transformation of the sea temperate moist air into dry continental, and the climate itself is rapidly changing from west to east. (3) The West Siberian Plain with the Altai and the Sayan Mountains, where the continentality of the climate intensifies from north to south. (4) Eastern Siberia with a pronounced continental climate - cold winters, warm summers; (5) Far East with a typically monsoonal climate.

In winter over Siberia, Central and Central Asia an area of ​​high atmospheric pressure regularly occurs - the Asian anticyclone. The coldest month of the year in Russia is January, on the shores of the seas - February. The lowest temperatures are in Eastern Siberia (the cold pole of Eurasia is located there, the average monthly temperature in January is minus 50 ° C). The absolute minimum (-68°C) was observed in Verkhoyansk in 1892, where the Pole of Cold obelisk was installed. An increase in temperatures is observed from February to July-August, from August - cooling. Great damage to the Russian agriculture It is applied by spring and autumn frosts, which is why almost the entire territory of the country belongs to the zone of risky farming.

The current general climate warming in Russia has been noted since the 1970s. and is unprecedented in the last 1000 years (0.9°C in 100 years). Major warming intervals: 1910–1945, 1970s and 1990s. 1998 is the warmest year of the 20th century. The most intense temperature increase was observed in the Baikal and Transbaikal regions, the reasons for it are interpreted hypothetically.

Soils. On the total area of ​​​​Russia in 17.1 million km 2 ground cover is 14.5 million km 2 (the rest falls on water bodies, rock outcrops, stony placers, disturbed and clogged lands). The soil cover is diverse: 90 natural soil types are supplemented by approximately the same number of anthropogenic-transforming types with their characteristic communities of plants, animals, and microorganisms. The standard of fertility (with a 16% content of humus-humus) in the International Chamber of Weights and Measures is a cube of chernozem, carved in the feather grass steppe near Voronezh and sent by soil scientist V.V. Dokuchaev in 1900 to the World Exhibition in Paris. Russia accounts for about 9% of the world's arable land, over 20% of the world's forest area. Tundra and swampy areas play an important economic role. However, the use of the soil cover, vast areas, highly fertile chernozems is difficult: 80% of the agricultural massif of Russia lies on the territory with low heat supply, 8% is occupied by swamps that require drainage, 7% are sands and stony soils.

The total area of ​​agricultural land of the country - 2.21 million km 2. The land suitable for plowing is extensive, but their share in the total area is lower than in other countries. Russian chernozems, intensively exploited for centuries, deteriorated their properties and now have reduced productivity (the balance of humus has been disturbed, the water regime has worsened). Plowed land in the last decades of the 20th century. exceeded environmentally acceptable standards and reached 70%, which led to the general degradation of the chernozem. Forest gray, dark chestnut soils are plowed up by 40%, sod-podzolic and meadow-steppe - from 10 to 15%. The area of ​​arable land by the 1980s was about 1.34 million square meters. km.

Large area of ​​arable land in Tue. floor. 20th century was supported by the use of low-fertility lands on the outskirts, but this did not save it from a reduction of 100 thousand square meters. km. Infertile lands began to be excluded from the involved arable lands, which made it possible to improve the quality of sowing, especially on plots given for personal use. Their areas are growing: from 1.6% of the total land area (1998) to 6.1% (2002). The area of ​​perennial plantations and unsown arable land continues to grow: from 250 thousand km 2 (1996) to 372 thousand square meters. km (2002).

But environmentalists are sounding the alarm about soil erosion: in the 1990s, the area of ​​leached soils doubled, in an unsatisfactory condition - more than 7 thousand km2. irrigated lands. Soil productivity decreases, soil pollution causes deterioration in the quality of water, air, and food. In some areas of the Belgorod region. soils are washed away to Cretaceous sediments; after the accident on Chernobyl nuclear power plant(1986) radioactive contamination of a number of nearby areas has reached disaster proportions.

Soils used as fodder lands occupy over 900 thousand km 2. The processes of their degradation are evident in places of unsystematic grazing. Thin, acidic, swampy soils of the tundra and taiga, used for reindeer pastures, are low-resistant to mechanical stress (oil production, industrial enterprises). Their annual reduction reaches 20 thousand square meters. km.

About 70% of the areas with a soil cover are occupied by forests, among which the main part is taiga. State nature reserves occupy 335 thousand square meters. km, national parks - 70 thousand square meters. km. The most surprising in terms of the duration of operation (over 100 years) and scientific significance is the man-made Stony Steppe in the southeast of the Voronezh region. (founded in 1892 by the expedition of V.V. Dokuchaev in the barren eroded steppe as a model of an ideal agricultural landscape).

Vegetable world. The vegetation cover of the Russian Federation includes zones of arctic polar deserts, tundras, boreal (with significant temperature fluctuations) taiga forests, broad-leaved forests, steppes, and deserts. Huge areas are occupied by mountains (Siberia, the Far East) with different altitudinal zonality of vegetation. Coasts of rivers, lakes, and seas have special vegetation. Lichens and mosses that hide the tiny flowers of the arctic polar deserts in the north are strikingly different from the three- to four-tiered forests in the taiga, and in the south from the subtropical vegetation of the Caucasus.

forest resources Russia accounts for 22% of the world's forest area and 1/4 of the world's timber reserves. The main forest-forming species and wood reserves (in descending order of the size of the occupied areas): larch, Scotch pine, downy and weeping birch (drooping), spruce, silver cedar pine. Coniferous and broad-leaved forests, streltsy steppes, floodplain meadows, Kuban floodplains have long been exposed to human influence; deforestation and fires have reduced their area, some forest and steppe spaces have been turned into lands and pastures.

Animal world. The fauna of Russia is the fauna of the temperate and cold zones of the Northern Hemisphere. The distribution of animals, their species diversity, abundance and ecological relationships are determined by latitudinal zonality. The structure of the fauna reflects its complex history, the diversity of sources and ways of formation.

Species diversity implies a division into fauna into a number of zones:

representatives of the Arctic Ocean and high-latitude islands (polar bear, seagull, narwhal, beluga whale),

tundra zone (deer, loons, arctic fox, etc.),

inhabitants of plateaus (snow sheep, leopard, Caucasian tour),

taiga zone (brown bear, elk, wolverine, sable, lynx).

forests of the European part of Russia (bison, European roe deer, mink, marten)

steppes and semi-deserts (saiga, manul, steppe ground squirrel, marmot, polecat)

animal world Far East (tiger, black bear, Bengal cat, raccoon dog, spotted deer).

The inhabitants of the Far Eastern seas and their coasts are diverse ( fur seal, cormorant, sea otter, whale, sperm whale, etc.), as well as pools southern seas(seal, shark, Russian sturgeon, stellate sturgeon, Volga pike perch, etc.).

Russia occupies one of the leading places in the world in terms of resources of wild animals (commercial fish, mammals, hunting animals and birds, aquatic invertebrates). The destructive nature of fisheries and the disappearance of natural habitats are the reasons for the reduction of a number of species of wild animals and wildlife resources. For more than 25 years, Russia has been taking measures to restore the number of fauna, including the removal of certain species of animals from economic use and their inclusion in the Red Book.