Which plains have crystalline shields. What is a shield? How are shields depicted on tectonic maps? Give examples of shields on various platforms

I won’t be mistaken if I say that almost everyone has some idea of ​​​​what a shield is. I propose to refresh and expand your knowledge of shields, their structure, and also get acquainted with the list of shields of our planet.

What is a shield

Any platform is made up of layers:

1. Crystal foundation.
2. Sedimentary cover.

Absolutely every platform consists of structures of four orders. The shield is one of the main structures, which is formed by the phenomenon of the lower layer of the platform - the crystalline foundation - coming out to the earth's surface. This foundation is exposed within the ancient platform. The dimensions of the shields in length can reach one thousand or more kilometers.

In the landscape, shields appear to us as plateaus, elevations, plateaus.

Shields on tectonic maps

Designations of a particular geological structure on the map may differ in color, and in the nature of the hatching, and in letter or number designation. The shields on the tectonic map are colored pink and have the letter designation - AR, which correspond to the Archean eon of the Precambrian period. The metamorphic and igneous rocks that make up the shields belong to the Precambrian period. What exactly are the breeds? This:

• granites;
• quartzites;
• gneisses.

Therefore, on the tectonic map within the shield there are inclusions of different colors and alphanumeric designations that indicate the presence of various igneous rocks. For example: bright pink areas marked τ1 correspond to granitoids of the Precambrian period, light orange areas marked ε1 correspond to alkaline igneous rocks of the Precambrian period.

Examples of shields on world platforms

The abundance of shields is observed on the African-Arabian platform. Here are a couple:

• Eburnian;
• Central African;
• Regibatskiy;
• Ahaggar.

Three shields formed on the S American Plate:

• Brazilian;
• Amazonian;
• Guianan.

The Hindustan platform also has a couple of shields within its limits:

• East Ghat;
• Dean's.

Only the Canadian Shield formed on the North American Platform, the Bereng Shield on the Hyperborean Platform, and the Central Australian Shield on the Australian Platform.

Crystal shield

(a. crystalline shield; n. Christallinschild; f. bouclier cristallin; and. escudo cristalino, escudo de cristal) is a large (up to a thousand km across) ledge of the Platform Foundation, which retained a steadily elevated position for most of its history and only for a short time, in the epochs of max. transgressions, overlapped by a shallow sea. Complex crystalline. shales, gneisses, granites, and other intrusive rocks. It is characterized by a reduced heat flow and an increased (150 km) thickness of the lithosphere. The Baltic and Ukrainian shields of the East European platform, the Aldan shield of the Siberian platform, and the Canadian shield of the North American platform can serve as examples of shields. Within the limits of the S.C., deposits are known: iron ores (for example, KMA, Krivoy Rog), ores of copper and nickel (for example, Pechenga), manganese (), gold (West Australia, South America) , (Aldan), ceramic. raw materials, etc.

Mountain Encyclopedia. - M.: Soviet Encyclopedia. Edited by E. A. Kozlovsky. 1984-1991 .

See what the "Crystal Shield" is in other dictionaries:

- (crystal shield), a large (up to 1000 km in diameter) ledge of the platform foundation, which over the course of evolution has retained a more or less constant position in terms of plan and height and only occasionally, during the greatest transgressions, flooded ... ... Geographic Encyclopedia

1. In tectonics, the largest positive platform structure. opposed to the plate. Within the ancient platforms, strongly metamorphosed and granitized Precambrian settlements emerge, and within the young ones, folded, metam. and magma. P.… … Geological Encyclopedia

Shield (geol.), the largest positive platform structure, opposed to a plate. Within Shch, highly metamorphosed Precambrian crystalline rocks (granites, gneisses, crystalline schists) come to the surface of the Earth, ... ...

I type of protective weapons (See Protective weapons); 1) A shield to repel bladed weapons was worn on the arm, threaded through belts or staples. The most ancient shields of various forms were made of wood, leather, and wicker rods. V … Great Soviet Encyclopedia

This article should be wikified. Please format it according to the rules for formatting articles ... Wikipedia

Ukrainian shield (Azov-Podolsky shield, Ukrainian crystalline massif) elevated southwestern part of the basement of the East European Platform. The length from the northwest from the Goryn River to the southeast to the coast of the Sea of ​​\u200b\u200bAzov is ... ... Wikipedia

A ledge of the Precambrian basement in the south of the East European platform. Ha N. W. and S. is bounded by the Dnieper-Donetsk and Pripyat grabens, in the west and south it gently sinks and is covered by a platform cover of the Paleozoic, Mesozoic and ... ... Geological Encyclopedia

Ukrainian Shield, blocky uplift of the basement in the southwestern part of the East European Platform (See East European Platform), stretching along the middle and lower reaches of the Dnieper. The area is about 200 thousand km2. Folded foundation… Great Soviet Encyclopedia

A ledge of the ancient crystalline basement of the Siberian Platform in the southeast of Central Siberia, mainly within the Aldan Highlands (Yakutia). The southern edge of the shield is uplifted and forms the Stanovoi Ridge. The most ancient (older than 2.5 billion years) ... ... Geographic Encyclopedia

Platforms of the lithosphere

Platforms are relatively stable areas of the earth's crust. They arise on the site of previously existing highly mobile folded structures, formed during the closure of geosynclinal systems, by their successive transformation into tectonically stable areas.

A characteristic feature of the structure of all lithospheric platforms of the Earth is their structure of two tiers or floors.

The lower structural floor is also called the foundation. The foundation is composed of highly deformed metamorphosed and granitized rocks, penetrated by intrusions and tectonic faults.

According to the time of formation of the foundation, the platforms are divided into ancient and young.

The ancient platforms, which also make up the core of modern continents and are called cratons, are of Precambrian age and formed mainly by the beginning of the Late Proterozoic. Ancient platforms are divided into 3 types: Laurasian, Gondwana and transitional.

The first type includes the North American (Lawrence), East European and Siberian (Angaris) platforms, formed as a result of the breakup of the supercontinent Laurasia, which in turn was formed after the breakup of the Pangea protocontinent.

To the second: South American, African-Arabian, Hindustan, Australian and Antarctic. The Antarctic platform before the Paleozoic era was divided into the Western and Eastern platforms, which united only in the Paleozoic era. The African platform in the Archaean was divided into the Congo (Zaire), Kalahari (South African), Somalia (East African), Madagascar, Arabia, Sudan, and Sahara protoplatforms. After the collapse of the Pangea supercontinent, the African protoplatforms, with the exception of Arabian and Madagascar, united. The final unification took place in the Paleozoic era, when the African platform turned into the African-Arabian platform as part of Gondwana.

The third intermediate type includes small-sized platforms: Sino-Korean (Huanhe) and South China (Yangtze), which at different times were both part of Laurasia and Gondwana.

Fig.2 Platforms and geosynclinal belts of the lithosphere

Archean and Early Proterozoic formations participate in the foundation of ancient platforms. Within the South American and African platforms, part of the formations belongs to the Upper Proterozoic time. The formations are deeply metamorphosed (amphibolite and granulite facies of metamorphism); the main role among them is played by gneisses and crystalline schists, granites are widespread. Therefore, such a foundation is called granite-gneiss or crystalline.

Young platforms formed in the Paleozoic or Late Cambrian time, they border the ancient platforms. Their area is only 5% of the total area of ​​the continents. The foundations of the platforms are composed of Phanerozoic sedimentary-volcanic rocks that experienced weak (greenschist facies) or even only initial metamorphism. There are blocks of more deeply metamorphosed ancient, Precambrian rocks. Granites and other intrusive formations, among which ophiolite belts should be noted, play a subordinate role in the composition. In contrast to the foundation of ancient platforms, the foundation of young ones is called folded.

Depending on the time of completion of the basement deformations, the division of young platforms into Epibaikalian (the most ancient), Epicaledonian and Epihercynian.

The first type includes the Timan-Pechora and Mysian platforms of European Russia.

The second type includes the West Siberian and East Australian platforms.

To the third: the Ural-Siberian, Central Asian and Ciscaucasian platforms.

Between the basement and the sedimentary cover of young platforms, an intermediate layer is often distinguished, which includes formations of two types: sedimentary, molasse or molasse-volcanic filling of intermountain depressions of the last orogenic stage in the development of the mobile belt that preceded the formation of the platform; detrital and detrital-volcanogenic filling of grabens formed at the stage of transition from the orogenic stage to the early platform

The upper structural stage or platform cover is composed of non-metamorphosed sedimentary rocks: carbonate and shallow sandy-clayey in platform seas; lacustrine, alluvial and bog in a humid climate on the site of the former seas; eolian and lagoonal in arid climate. The rocks occur horizontally with erosion and unconformity at the base. The thickness of the sedimentary cover is usually 2-4 km.

In a number of places, the sedimentary layer is absent as a result of uplift or erosion, and the foundation comes to the surface. Such sections of platforms are called shields. On the territory of Russia, the Baltic, Aldan and Anabar shields are known. Within the shields of ancient platforms, three complexes of rocks of the Archean and Lower Proterozoic age are distinguished:

Greenstone belts, represented by thick sequences of regularly alternating rocks from ultrabasic and basic volcanics (from basalts and andesites to dacites and rhyolites) to granites. Their length is up to 1000 km with a width of up to 200 km.

Complexes of ortho- and para-gneisses, which, in combination with granite massifs, form fields of granite-gneisses. Gneisses correspond in composition to granites and have a gneiss-like texture.

Granulitic (granulite-gneiss) belts, which are metamorphic rocks formed under conditions of medium pressure and high temperatures (750-1000 ° C) and containing quartz, feldspar and garnet.

Areas where the foundation is covered everywhere by a thick sedimentary cover are called slabs. Most of the young platforms are sometimes referred to simply as slabs for this reason.

The largest elements of the platforms are syneclises: vast depressions or troughs with slope angles of only a few minutes, which correspond to the first meters per kilometer of movement. As an example, we can name the Moscow syneclise with its center near the city of the same name and the Caspian syneclise within the Caspian lowland. In contrast to syneclises, large platform uplifts are called anteclises. On the European territory of Russia, the Belarusian, Voronezh and Volga-Ural anteclises are known.

Grabens or aulacogens are also large negative elements of the platforms: narrow extended sections, linearly oriented and limited by deep faults. There are simple and complex. In the latter case, along with deflections, they include uplifts - horsts. Effusive and intrusive magmatism is developed along the aulacogenes, which is associated with the formation of volcanic covers and explosion pipes. All igneous rocks within the platforms are called traps.

Smaller elements are shafts, domes, etc.

Lithospheric platforms experience vertical oscillatory movements: they rise or fall. Such movements are associated with the transgressions and regressions of the sea that have repeatedly occurred throughout the entire geological history of the Earth.

In Central Asia, the formation of the mountain belts of Central Asia: Tien Shan, Altai, Sayan, etc. is associated with the latest tectonic movements of the platforms. Such mountains are called revived (epiplatforms or epiplatform orogenic belts or secondary orogens). They are formed during orrogenesis epochs in areas adjacent to geosynclinal belts.

In the tectonic structure of the Russian Plain, scientists geologists distinguish very diverse structures of the most ancient Precambrian crystalline platform. The orographic pattern of the relief of the territory is represented mainly by flat, elevated and low-lying areas.

History of occurrence

The formation of the relief of the vast Russian Plain at all times was strongly influenced by numerous factors of nature, the main ones being water, wind and the work of the ancient glacier. The crystalline basement of the platform in the area of ​​the Ukrainian and Baltic shields was formed in the early Archean period 3.2-3.5 billion years ago. Later, during the Sami stage of folding 2.5-3 billion years ago, the cores of the most ancient protoplatforms were formed; today they are preserved in the form of gneiss and granite intrusions. During the White Sea stage of folding 2.5-1.9 billion years ago, ancient igneous rocks erupted and solidified in the same places on the Russian platform. In the Middle Proterozoic, the next stage in the formation of the Karelian territory began. It lasted 1.9-1.6 billion years ago. Granite intrusions again intruded into the body of the Baltic tectonic shield, strata of crystalline schists, effusives and metamorphic deposits were formed. The foundation of the ancient platform under the landforms is located at different depths. In the regions of the Kola Peninsula and Karelia, it appears as a Baltic tectonic shield above the land surface. With the presence of this structure, geologists consider the formation of the Khibiny Mountains. In other areas, a thick cover of sedimentary rocks formed above the basement. Elevated areas were formed by raising the foundation, tectonic troughs or glacier activity.

Tectonic structures

Different structures are located in different zones of the lithosphere. They are vast areas, their boundaries lie along deep tectonic faults. The main structures in tectonics are ancient platforms and fold belts. The platform is a stable flat tectonic structure. The platform is most often located in zones destroyed during the geological periods of the fold belts. The structure of the platform is two-tiered. Below is a tier of a crystalline solid foundation made of ancient rocks. From above it is covered with a cover of sedimentary rocks, formed much later. On the platform, geologists distinguish between stable slabs and rock outcrops, shields. In the areas of plates, the foundation is located at great depths and is completely covered with a sedimentary cover. In the area of ​​the shield, the foundation of the platform comes to the surface. The platform cover here is not solid and low-power. In the mobile belts, active mountain building processes continue today.

The structure of the tectonic strata

The nature of the orographic relief pattern of the Russian Plain is flattened, but it distinguishes between elevated and low-lying areas. It depends on the features of the tectonics of the plain. The tectonic structures of the plain are heterogeneous; modern movements of the earth's crust manifest themselves in different ways. The ancient Russian platform is formed from various tectonic elements. These are shields, anteclises, syneclises and aulacogens.

Shields

In the structure of the ancient Russian platform, geologists identify in the north the Baltic and to the south the Ukrainian tectonic shields. The rocks of the Baltic tectonic shield appear in Karelia and on the Kola Peninsula, the territory of the shield continues into northern Europe. Archean and Proterozoic rocks are overlain here by modern alluvial deposits of the Quaternary period. From the coast of the Sea of ​​Azov through the Dnieper Upland to the southern Polissya, there are outcrops of rocks of the Ukrainian tectonic shield. It is covered with deposits of the Tertiary age, its rocks appear along the river valleys.

Between these shields, the foundation of the ancient platform lies at great depths. They are calculated up to 1000 m, on the Belarusian anteclise up to 500 m.

Anteclises

Geologists call anteclises zones where the foundation of the platform is shallow. The most significant of the anteclises Voronezh and east of the Volga-Urals are located in the center of the plain. The Volga-Ural tectonic structure includes depressions and uplifts. The thickness of sedimentary deposits here is up to eight hundred meters. It can be seen from the occurrence of rocks that, in general, the structure of the Voronezh anteclise descends towards the north. The basement here is covered mainly by thin Carboniferous, Devonian and Ordovician deposits of rocks. Cretaceous, Carboniferous, and Paleogene deposits appear in the southern part of the anteclise.

The tectonics of another anteclise on the Russian platform, the Donetsk Ridge, is interesting. This is a folded Early Paleozoic peneplainized mountain structure. To the south, in Ciscaucasia, there is a folded region of Paleozoic age. Today, scientists consider the ridge to be the northern edge of this folded area.

syneclises

Tectonic scientists call syneclises areas where the foundation of an ancient platform is located at great depths. The oldest and rather complex in structure is the syneclise of the Moscow tectonic zone. The Moscow depression is based on aulacogenes, deep tectonic ditches filled with thick Riphean deposits. Above the basement is a sedimentary cover of Cambrian and Cretaceous rocks. In the Neogene and Quaternary geological periods, the syneclise experienced a powerful uneven uplift. This is how the Smolensk-Moscow and later, by geological standards, the Valdai Uplands appeared, along with them the North Dvina and Upper Volga lowlands. The Pechora syneclise is interesting in its geological structure. Its uneven block foundation is located at depths of up to 6,000 meters. It is overlain by thick Paleozoic, later Mesozoic and Cenozoic rock strata. One of the deepest on the Russian platform is the Caspian syneclise. The foundation of the Russian platform is located in this area at a depth of up to 10 km.

Aulacogens

Geologists call aulacogenes deep ancient tectonic faults and ditches. To similar structures on the Russian platform, scientists include the Moscow, Soligalichsky and Kresttsovsky tectonic ditches.

Outcrops of the Baikal folding

On the Russian platform there is an outcrop of the Early Paleozoic Baikal folding, a low upland called the Timan Ridge. It stretches from the northwest to the southeast for 900 km from the Czech Bay to the Barents Sea. In the north, its tundra and forest-tundra part is represented by low hills, reaching a height of 303 meters. In the central part of the ridge between the rivers Pizhma Mezen and Pechora is the highest peak of the Chelassky Stone mountain system, its height is 471 meters. To the south, the taiga is located on a low plateau dissected by river valleys up to 350 meters high. Rich deposits of titanium and aluminum ores in Devonian basalts are associated here with rocks of the Baikal folding. The richest oil and gas deposits are confined to this territory. Oil shale, peat, building materials are associated with sedimentary rocks.

The connection of the tectonic structure with minerals

Over a very long period of development, the most ancient Russian platform is represented by a rather powerful geostructure. The richest deposits of various minerals have been explored in its bowels. In the area of ​​the Kursk magnetic anomaly, iron ores have been found that belong to the Precambrian basement. The sedimentary cover contains coal. High-quality coals are mined in the Donetsk and Moscow region lignite basin. Gas and oil have been found in Mesozoic and Paleozoic rocks in the Ural-Volga basin. Oil shale lies near Syzran. Deposits of building materials, phosphorites, bauxites and salts are associated with the rocks of the sedimentary cover of the Russian Plain.

Relationship between tectonics and relief

On the Russian Plain there is a flattened flat relief. This is primarily a consequence of its complex tectonic structure. Irregularities in the basement of this tectonic structure appear in the relief as large low and high areas. The Voronezh tectonic uplift caused the appearance of the Central Russian Upland. Large troughs in the foundation of the platform formed the Caspian lowland in the south and the Pechora lowland in the north. Almost the entire northern part of the Russian Plain is lowland. It is a seaside low-lying plain with small elevated areas. Here is located the Smolensk-Moscow elevated zone, the Valdai and the Northern Uvalov upland. The area is a watershed between the Atlantic, the Arctic Ocean basin and the Aral-Caspian drainless region. In the south, there are vast low-lying areas of the Black Sea and Caspian Sea. The highest height up to 479 m is observed on the plain in the area of ​​the Bugulma-Belebeevskaya Upland.

Geologists have discovered volcanic intrusions in the sedimentary cover of the Russian Platform. This means that on the platform after the Proterozoic era, there were more manifestations of ancient volcanism in the Devonian period. The orographic pattern of the Russian Plain depends on the tectonic structure and processes. All elevated and low-lying areas on the plain are of tectonic origin. The relief depends on the structure of the foundation of the ancient platform. Geologists consider the Baltic crystalline shield to be the cause of uplifts in the relief of Karelia and the Kola Peninsula. The Ukrainian tectonic shield became the reason for the appearance of the Azov and Dnieper uplands. The Voronezh anteclise was the reason for the emergence of the Central Russian Upland. On the syneclises of the south of the vast plain are today the Caspian and Black Sea lowlands. The modern relief does not always correspond to the tectonic structures in the center of the plain. So, the Northern Uvaly are located on the Moscow syneclise. The Volga upland region is located on the Ulyanovsk-Saratov syneclise. The Oka-Don lowland zone is located in the east of the Voronezh large anteclise.

Erosion of the earth's surface proceeds vigorously in the elevated areas of the Russian Plain. Such areas can be identified on maps by bedrock outcrops that are surrounded by newer deposits. The areas of subsidence of the earth's crust have become zones of accumulation of loose sedimentary rocks of the Quaternary age, where erosion processes are weakly manifested.

The territory of Russia is based on large tectonic structures (platforms, shields, folded belts), which are expressed in various forms in modern times - mountains, lowlands, uplands, etc.

On the territory of Russia there are two large ancient Precambrian platforms (their foundation was formed mainly in the Archean and Proterozoic) - these are Russian and Siberian, as well as three young ones (West Siberian, Pechora and Scythian). The idea of ​​\u200b\u200band the conditions for the occurrence of rocks is reflected in the tectonic.

On the East European Platform within Russia is the Baltic shield , on the Siberian - Aldan and Anabar.

On the East European platform is the Russian plate , on the Siberian - Leno-Yenisei.

Young platforms in Russia do not have foundation outcrops to the surface. A cover of sedimentary rocks has accumulated almost everywhere on them, that is, they are entirely represented by plates. For example, on the West Siberian platform - the West Siberian plate, etc.

Platform slabs are associated with such largest ones as plains different heights. On the Russian plate is (East European), on the Leno-Yenisei - the Central Siberian plateau, on the West Siberian - the West Siberian lowland, on the Pechora - the Pechora lowland, on the Scythian - the plains of the Ciscaucasia. The presence on the territory of Russia of several large platforms led to the fact that the plains occupy three-quarters of the territory of Russia.

East European platform

Within the Russian Plate, the basement of the ancient East European Platform is overlain by a sedimentary cover of rocks predominantly of Paleozoic and Mesozoic age. The cover in different areas has different power. Above the basement depressions, it reaches 3 km or more. Although the irregularities in the basement are smoothed out by sedimentary rocks, some of them are reflected in the relief. The heights of most of the Russian Plain are less than 200 m, but there are also elevations within it (Middle Russian, Smolensk-Moscow, Volga, Northern Uvaly, Timan Ridge).

Both the basement rocks and the sedimentary cover contain large deposits. Among the ore minerals, iron deposits of sedimentary-metamorphic origin, confined to the crystalline basement, are of the greatest importance. Deposits of copper-nickel, aluminum ores and apatites are associated with igneous rocks of the shield. A variety of sedimentary rocks contain oil, gas, coal and brown coal, rock and potassium salts, phosphorites, bauxites.

Siberian platform

Within the Lena-Yenisei plate of the Siberian platform, the ancient crystalline basement is buried under a thick cover of mostly Paleozoic deposits. A feature of the geological structure of the Siberian Platform is the presence of traps - igneous rocks that have erupted onto the surface or solidified in sedimentary strata.

The Central Siberian Plateau has a height of 500-800 m above sea level, the highest point is at (1701 m).

The foundation and sedimentary layer of the Siberian Platform contain a huge amount of minerals. There are large iron ore deposits in the basement rocks and ladders. Diamonds and copper-nickel ores with chromium and cobalt are confined to the igneous rocks intruded into the sedimentary cover. In the Paleozoic and Mesozoic strata of sedimentary rocks, huge accumulations of hard and brown coals, potash and table salts, oil and gas were formed.

West Siberian Platform

The foundation of the young West Siberian platform is a destroyed mountain structure created in the era of the Hercynian and Baikal folding. The basement is overlain by a thick cover of Mesozoic and Cenozoic marine and continental predominantly sandy-argillaceous deposits. Huge reserves of oil and gas, brown coal, and iron ores of sedimentary origin are associated with Mesozoic rocks.

The heights of the predominant part of the West Siberian Plain do not exceed 200 m.

Platforms are framed mountain-fold areas , which differ from platforms in the nature of the occurrence of rocks and the high mobility of the earth's crust.

For instance:

The Russian Plain is separated from the West Siberian by the ancient , stretching from north to south for 2.5 thousand km.

From the southeast, the West Siberian Plain is bordered by Altai mountains.

The Siberian platform from the south is framed by the belt of mountains of Southern Siberia. In modern relief, this Baikal mountain country, Sayans, Yenisei Ridge.

On the Aldan Shield of the Siberian Platform, Stanovoy Range and are located.

To the east of the Lena River, up to, as well as in, there are significant mountain ranges (ridges: Chersky, Verkhoyansk, Kolyma Highlands).

In the extreme northeast and east of the country, the Pacific folding belt passes, including the island and the ridge of the Kuril Islands. Further south, this area of ​​young mountains continues into the Japanese Islands. The Kuril Islands are the peaks of the highest (about 7 thousand m) mountains rising from the bottom of the sea. Most of them are under water.

Powerful mountain building processes and shifts (Pacific and Eurasian) in this region continue. Evidence of this are intense earthquakes and seaquakes. The places of volcanic activity are characterized by hot springs, including periodically spouting geysers, as well as emissions of gases from craters and cracks, which indicate active processes in the depths of the bowels. Active volcanoes and geysers are most widely represented on the Kamchatka Peninsula.

The mountain-folded regions of Russia differ from each other in the time of formation.

On this basis, five types of folded areas are distinguished.

1. Areas Baikal and Early Caledonian folding(700 - 520 million years ago) the territories of the Baikal region and, the Eastern Sayan, Tyva, the Yenisei and Timan ridges were formed.

2. Areas of Caledonian folding(460-400 Ma) formed the Western Sayan, Gorny Altai.

3. Areas of Hercynian folding(300 - 230 million years) - Ural, Rudny Altai.

4. Areas of Mesozoic folding(160 - 70 million years) - North-East of Russia, Sikhote-Alin.

5. Areas of Cenozoic folding(30 million years before the present) - the Caucasus, the Koryak Highlands, Kamchatka, Sakhalin, the Kuril Islands.

Folded regions of pre-Cenozoic age arose at the boundaries of ancient lithospheric plates during their collision. The number, size and shape of lithospheric plates have changed many times over the course of geological history. The convergence of ancient lithospheric plates caused the collision of continents with each other and with island arcs. This led to the collapse of the sedimentary strata accumulated in the margins of the continents into folds and the formation of folded mountain structures. This is how the Caledonian folding regions of Altai and Sayan appeared in the Early Paleozoic, the Hercynian folds of the Altai Mountains, the Urals, the basement of the West Siberian and Scythian young platforms in the Late Paleozoic, and the folded regions of the Northeast and Far East of Russia in the Mesozoic.

The formed folded mountains collapsed over time under the influence of external forces: weathering, the activity of the sea, rivers, glaciers, and wind. In place of the mountains, relatively leveled surfaces were formed on a folded base. Subsequently, vast areas of these territories experienced only slow ups and downs. During the periods of subsidence, the territories were covered by the waters of the seas and horizontally occurring sedimentary rocks were accumulated. This is how the young West Siberian, Scythian, Pechora platforms were formed, having a folded basement consisting of destroyed mountains, and a cover of sedimentary rocks. Large areas of pre-Cenozoic folded areas experienced uplifts in the second half of the Cenozoic. Faults formed here, breaking the earth's crust into blocks (lumps). Some rose to different heights, forming the revived blocky mountains and highlands of Southern and North-Eastern Siberia, the south of the Far East, the Urals, and Taimyr.

Mountain-folded areas are separated from adjacent platforms either faults , or marginal (piedmont) troughs . The largest troughs are Cis-Ural, Cis-Verkhoyansk and Ciscaucasian.