In this article we will tell you about the Alpine-Himalayan seismic belt, because the whole history of the formation of the landscape of planet Earth is connected with theory and the seismic and volcanic manifestations accompanying this movement, as a result of which the current relief was formed. earth's crust... The relief-forming movements of tectonic plates are accompanied by disturbances in the continuous field of the earth's crust, which lead to the formation of tectonic faults and vertical mountain ranges in it. Such discontinuous processes occurring in the earth's crust are called faults and overthrusts, respectively leading to the formation of horsts and grabens. The movement of tectonic plates ultimately leads to intense seismic manifestations and volcanic eruptions. There are three types of plate movement:
1. Rigid mobile tectonic plates move on top of each other, forming mountain ranges, both in the oceans and on land.
2. Contiguous tectonic plates sink into the mantle, forming tectonic trenches in the earth's crust.
3. Moving tectonic plates slide between each other, forming transform faults.
The belts of maximum seismic activity of the planet approximately coincide with the line of contact of moving tectonic plates. There are two main belts:
1. Alpine–Himalayan seismic belt
2. Pacific seismic belt.

Below we will dwell on the Alpine-Himalayan seismic belt, which stretches as a strip from the mountain structures of Spain to the Pamirs, including the mountains of France, the mountain structures of the center and south of Europe, its southeast and further - the Carpathians, the Caucasus and Pamir mountains, as well as mountain manifestations Iran, northern India, Turkey and Burma. In this zone of active manifestation of tectonic processes, most catastrophic earthquakes occur, bringing countless disasters to countries falling into the zone of the Alpine-Himalayan seismic belt. These are catastrophic destruction in settlements, numerous casualties, violations of transport infrastructure, and so on ... So in China, in 1566, there was a powerful earthquake in the provinces of Gansu and Shaanxi. During this earthquake, more than 800 thousand people died, and many cities were wiped off the face of the earth. Calcutta in India, 1737 - about 400 thousand people died. 1948 - Ashgabat (Turkmenistan, USSR). The dead - more than 100 thousand. 1988, Armenia (USSR), the cities of Spitak and Leninakan were destroyed to the ground. 25 thousand people died. You can list other fairly powerful earthquakes in Turkey, Iran, Romania, accompanied by great destruction and loss of life. Almost daily seismic monitoring services register weaker earthquakes throughout the Alpine-Himalayan seismic belt. They testify that tectonic processes in these areas do not stop even for a minute, the movement of tectonic plates also does not stop, and after another powerful earthquake and another release of the earth's crust, it again grows to a critical point, at which, sooner or later - inevitably there will be another discharge of the tense earth's crust, causing an earthquake.
Unfortunately, modern science cannot accurately determine the place and time of the next earthquake. In active seismic belts of the earth's crust, they are inevitable, since the process of movement of tectonic plates is continuous, and hence the continuous increase in tension in the zones of contact between moving platforms. With the development of digital technologies, with the advent of super powerful and ultra-high-speed computer systems, modern seismology will come closer and closer to the fact that it will be able to produce mathematical modeling of tectonic processes in Russia, which will make it possible to determine the points of the next earthquake with the utmost accuracy and reliability. This, in turn, will provide an opportunity for humanity to prepare for such disasters and help to avoid numerous human casualties, and modern and promising building technologies will minimize the devastating consequences. powerful earthquakes. It should be noted that other active seismic belts on the planet coincide quite closely with the belts of volcanic activity. Science has proven that in most cases volcanic activity is directly related to seismic activity. Like earthquakes, increased volcanic activity poses a direct threat to human life. Many volcanoes are located in densely populated areas with developed industry. Any sudden volcanic eruption carries a danger to people living in the area of ​​volcanoes. In addition to the above, earthquakes in the oceans and seas lead to tsunamis, which are no less destructive for coastal zones than the earthquakes themselves. It is for this reason that the task of improving the methods of seismic monitoring of active seismic belts always remains relevant.

A folded belt that crosses Northwest Africa and Eurasia in a latitudinal direction from the Atlantic Ocean to the South China Sea, separating the southern group of ancient platforms, to the middle Jurassic constituting the supercontinent Gondwana, from the northern group that previously constituted the continent Laurasia and the Siberian platform. In the east, the Mediterranean fold belt articulates with the western branch of the Pacific geosynclinal belt.

The Mediterranean belt covers the southern regions of Europe and the Mediterranean, the Maghreb (North-West Africa), Asia Minor, the Caucasus, the Persian mountain systems, the Pamirs, the Himalayas, Tibet, Indochina and the Indonesian islands. In the middle and central parts of Asia, it is almost united with the Ural-Mongolian geosynclinal system, and in the west it is close to the North Atlantic system.

• Mesozoids -
  • Indo-Sinian (Tibeto-Malay);
  • West Turkmen (Nebitdag);

• Alpides -
  • Caucasian;
  • Crimean;
  • Balkan;
  • Central European;
  • Apennine;
  • North Magribskaya;
  • Iranian-Omani;
  • Kopetdago-Elbursk;
  • Baluchistan;
  • Afghan-Tajik;
  • Pamir;
  • Himalayan;
  • Irrawaddy;
  • West Malay

Notes

Links

TOPIC 3GENERAL FEATURES OF THE GEOLOGICAL STRUCTURE OF THE AREAS OF THE ALPINE FOLDING (GEOLOGY OF THE GREATER CAUCASUS, THE FOLDED REGION OF THE EASTERN CARPATHIANS AND MOUNTAIN CRIMEA)

Task 4 Scheme of the structures of the Alpine folded region of the Greater Caucasus

Target: draw a diagram of the structures of the folded region of the Greater Caucasus

Work plan:

1 Legend to the scheme of structures of the Greater Caucasus

2 Border of the Greater Caucasus

3 Main structural elements of the Greater Caucasus

Materials:

• Literature: Koronovsky N.V.

A short course in regional geology of the USSR. – Ed. Moscow University, 1984. - 334 p., Lazko E.M. Regional geology of the USSR. Volume 1, European part and Caucasus. - M.: Nedra, 1975.

– 333 pp., lecture notes on the geology of the East European Platform.

Basic concepts for the task

In the north, the boundary between the meganticlinorium of the Greater Caucasus and the Scythian plate is drawn along the top of the Cretaceous deposits. To the south of the anticlinorium is the Southern Slope of the Greater Caucasus, which is an alpine geosynclinal trough composed of deposits of the Lower - Upper Jurassic.

The diagram shows the following structural elements of the Greater Caucasus: the Main Anticlinorium, the Peredovoi Ridge, the North Caucasian monokinal, the southern slope of the Greater Caucasus, the Rionsky and Kurinsky troughs, the Dzirullsky massif, the Azerbaijan folded zone.

When selecting the above structural elements The Greater Caucasus should take into account the following features.

Within the limits of the Main Anticlinorium, Precambrian rocks penetrated by Mesozoic and Alpine, mainly granitoid intrusions, come to the surface.

In the structures of the Peredovoi Ridge, deposits of the Middle, Upper Cambrian and Silurian, Middle, Upper Devonian and Lower Carboniferous (Paleozoic), intruded by intrusions of acidic, intermediate and ultrabasic composition and the molassoid sequence of the Middle, Upper Carboniferous and Permian are exposed.

The North Caucasian monokinal is located north of the structures of the Main Anticlinorium and the Front Range. Its cover is represented by Jurassic and Cretaceous deposits.

The southern slope of the Greater Caucasus lies south of the anticlinorium.

It is filled with Middle Jurassic and Cretaceous rocks.

The Rionsky and Kurinsky troughs are located between the folded structures of the Greater and Lesser Caucasus.

They are outlined by Cenozoic deposits.

The Dzirula massif separates the Rionsky and Kurinsky troughs. Here Riphean and Paleozoic rocks with Hercynian and Cimmerian granites come to the surface.

The Azerbaijani folded zone is located in the eastern part of the meganticlinorium and is delineated by the Pliocene-anthropogene deposits.

Progress

Task 5 Scheme of the structures of the Alpine folded regions of the Eastern Carpathians and the Crimean Mountains

Target: draw up a diagram of the structures of the Eastern Carpathians and the Mountainous Crimea

Work plan:

1 Legend to the scheme of structures of the folded system of the Eastern Carpathians

2 The boundary of the fold system of the Eastern Carpathians

3 Main structural elements of the Eastern Carpathians

4 Boundary of the folded system of the Crimean Mountains

Materials:

• Tectonic map of Europe and adjacent areas M 1:22500000, Geological map of the USSR M 1:4000000, contour map Europe M 1: 17000000 - 20000000;
• a notebook for practical exercises, a simple soft pencil, a set of colored pencils, an eraser, a ruler;
• Literature: Koronovsky N.V.

A short course in regional geology of the USSR. – Ed. Moscow University, 1984. - 334 p., Lazko E.M. Regional geology of the USSR. Volume 1, European part and Caucasus. - M.: Nedra, 1975. - 333 p., lecture notes on the geology of the East European platform.

Basic concepts for the task

The meganticlinorium of the Eastern Carpathians has a well-pronounced longitudinal structural-facies zonality and thrusting of the inner zones on the outer and the latter on the Cis-Carpathian marginal foredeep.

The following structural elements of the Eastern Carpathians are displayed on the diagram: Pre-Carpathian foredeep, Skibova zone, Marmarosh crystalline massif, Cliffs zone, Transcarpathian foredeep. In addition, the folded region of the Crimean Mountains should be outlined on the diagram.

When highlighting the above structural elements of the Eastern Carpathians, the following features should be taken into account.

The Carpathian foredeep is located on the border of the folded structure of the Eastern Carpathians and the East European Platform.

It is filled with Miocene deposits.

The skib zone is the outermost part of the Carpathians. It is outlined by pomelo and Paleogene deposits.

The Marmarosh crystalline massif occupies an internal position in the extreme southeast.

The oldest Proterozoic-Mesozoic rocks are exposed within the Marmarosh massif. The deposits are intruded by Middle Paleozoic granitoids. Upper Carboniferous, Permian, Triassic, and Jurassic deposits overlain by Upper Cretaceous and Cenozoic deposits also participate in the cover structure of the Marmarosh massif.

The Marmarosh massif narrows to the north-west and further there is the Cliffs Zone, which is expressed by a narrow, sometimes double stripe of outcrops of Triassic, Jurassic and Cretaceous deposits randomly scattered among Cretaceous and Paleogene rocks.

From the rear, inner side, the mountain structure of the Carpathians is limited by the Transcarpathian marginal foredeep. It is made by Neogene molasses.

When identifying the folded region of the Crimean Mountains, it must be taken into account that its borders extend from the city of

Sevastopol in the west of the Great Dane. Feodosiya in the east. The northern boundary separates the Crimean Mountains from the structures of the Scythian plate and runs along the top of the Cretaceous deposits.

Progress, the methodology for its implementation and design is similar to those in tasks 1 and 2.

TOPIC 4MAIN FEATURES OF THE GEOLOGICAL STRUCTURE OF BELARUS

Task 6 Describe the main structures of the territory of Belarus on the basis of cartographic materials

Target: Describe the main structures of the territory of Belarus, expressed in the foundation, using cartographic materials

Structure description plan:

1 The name of the structure of the 1st order and the structures of the 2nd order distinguished in their composition.

2 The boundaries of the structure of the first order.

3 Foundation depths - minimum and maximum depths within the boundaries of the structure of the 1st order, depths of occurrence within the structures of the 2nd order, characteristic features of the occurrence of the foundation surface.

4 Time and conditionality of structure formation.

6 Characteristics of the main discontinuous disturbances that limit the structures of the 1st order and separating the structures of the 2nd order (rank, time of formation, location, length, width of the zone of influence, vertical amplitude, plan outlines, activity at the present stage).

7 Structural complexes and floors (name, distribution and rocks of which formations are composed).

Materials:

• tectonic maps of Belarus M 1:500000 and M 1: 1000000;
• notebook for practical exercises
• Literature: Geology of Belarus: monograph // Ed.

A.S. Makhnach - Minsk, 2001. - 814 p., Faults of the earth's crust of Belarus: monograph // Ed. Iceberg. Minsk: Krasiko-Print, 2007. - 372 p., STB Symbols for maps of geological content (working draft). - Minsk: Ministry of Natural Resources, 2011.

– 53 p., lecture notes on the geology of Belarus.

Indolo-Kuban trough

Page 1

The Indolo-Kuban trough is a foothill.

The Miocene-Pliocene deposits of the Indolo-Kuban trough include mainly sandy strata of the Chakrakian-Karaganian, Sarmatian, Meotic and Pontic age, which are associated with the Anastasievsko-Troitskoye oil and gas field. The commercial oil and gas potential of the deposit was revealed in the Cimmerian, Pontic, Meotic and Sarmatian deposits.

The mineralization of the waters of the Sarmatian rocks in the Western Ciscaucasia increases from east to west, reaching a maximum (60 g/l) in the central part of the trough. At the same time, the composition of the waters changes from sodium sulfate to hydrocarbonate-sodium and chloride-calcium.

In the central part of the Indolo-Kuban trough below the cut surface - 4 5 km, Paleogene-Lower Neogene deposits will be opened by boreholes.

The Vostochno-Severskoye field is located on the southern side of the Indolo-Kuban trough. The deposit is very complicated and represents an anticlinal fold in the Eocene and Oligocene sediments of the Paleogene, buried under the monoclinal deposits of the Neogene. The strike of the structure is close to latitudinal, the fold is asymmetric: the northern limb is steeper than the southern one.

The Anastasievsko-Troitskoye gas condensate and oil field is located in the Indolo-Kuban trough.

The field is multilayer, discovered in 1952. Gas deposits are associated with the Cimmerian and Pontic horizons, and oil deposits with the Maeotic horizon.

Against the background of highly mineralized calcium chloride waters of meotic deposits in the central part of the Indolo-Kuban trough, a hydrochemical minimum is observed within the Anastasievsko-Troitskaya fold, associated with the intrusion of low-mineralized waters from the diapiric core.

The above water heads decrease from east to west from 400 to 160 m and are due to the infiltration regime. In the most submerged part of the Indolo-Kuban trough in the area of ​​the Anastasievsko-Troitskoye deposit, an elision regime exists in the Miocene deposits and extensive AHFP zones have been established.

ALPINE-HIMALAYAN MOBILE BELT

The southern part of the basin, adjacent to the Kerch and Taman peninsulas, is located within the Indolo-Kuban trough and experiences intense subsidence. The thickness of marine Holocene sediments here reaches a few tens of meters.

Clayey and clayey-aleuritic silts predominate among them with admixture of mollusk shells of varying amounts.

The Shirokaya Balka-Veselaya deposit, discovered in 1937, is located within the southern edge of the Indolo-Kuban trough.

Here, in the sediments of the middle Maykop, a band of sandy-silty rocks was revealed, in the southern part of which bay-like ledges form a series of lithological traps filled with oil. One of them is called Wide Beam, the other is called Veselaya.

They are united by a common oil-bearing band.

The Ancestral Belt in front of their fore troughs: I ] - Terek-Caspian and Kusaro-Divn - Chinsky troughs; b, Indolo-Kuban trough. III, Transcaucasian intermountain trough: III] - Dzirulsko-Okrnba zone of uplifts; SH2, piedmont troughs of Western Georgia; SH3, Colchis trough; SH4, Ku-ra depression; Ills - Apsheron-Kobystan trough.

Meganticlinorium of the Lesser Caucasus: IVi, Adjara-Trialeti folded zone; IVa, Somkheto-Karabakh anticlinorium; IV3 - Sevan synclinorium; IV4 - Zangezur-Ordubad zone; IVS, Armenian-Akhalkalaki volcanic shield; IVa, Araks depression; IV.

The Novodmitrievskoe deposit, discovered in 1951, is located within the Kaluga belt of buried anticlines that complicate the southern side of the Indolo-Kuban trough, is an anticline fold of almost latitudinal strike (with a deviation to the southeast), complicated by a large number of disjunctive faults.

In addition to the considered Ust-Labinskoye and Nekrasovskoye fields, in the southern part of the Yeisk-Berezan uplift zone, confined to the Ust-La, the Binsky ledge of the basement separating the East Kuban depression from the Indolo-Kuban trough, there are Dvubratskoe and Ladoga deposits.

Within the Crimean Steppe, in addition to the Sivash depression, other main tectonic elements are: the Novoselovsko-Simferopol uplift of the Paleozoic basement, which plunges into the Alma depression in the west, and passes into the Indolo-Kuban trough in the east.

Pages:      1    2

Mediterranean (Alpine-Himalayan) folded (geosinklinal) belt- a fold belt that crosses Northwest Africa and Eurasia in a latitudinal direction from the Atlantic Ocean to the South China Sea, separating the southern group of ancient platforms, which until the middle of the Jurassic period constituted the Gondwana supercontinent, from the northern group, which previously constituted the Laurasia continent and the Siberian platform.

In the east, the Mediterranean fold belt articulates with the western branch of the Pacific geosynclinal belt.

The Mediterranean belt covers the southern regions of Europe and the Mediterranean, the Maghreb (North-West Africa), Asia Minor, the Caucasus, the Persian mountain systems, the Pamirs, the Himalayas, Tibet, Indochina and the Indonesian islands.

Alpine-Himalayan seismic belt

In the middle and central parts of Asia, it is almost united with the Ural-Mongolian geosynclinal system, and in the west it is close to the North Atlantic system.

The belt was formed over a long period of time, covering the period from the Precambrian to the present day.

The Mediterranean geosynclinal belt includes 2 folded areas (mesozoids and alps), which are divided into systems:

Cm.

Notes

1. Zeisler V.M., Karaulov V.B., Uspenskaya E.A., Chernova E.S. Fundamentals of regional geology of the USSR. - M: Nedra, 1984. - 358 p.

Links

Fold belts on the world map

Zones with seismic activity, where earthquakes occur most often, are called seismic belts. In such a place, increased mobility of lithospheric plates is observed, which is the reason for the activity of volcanoes. Scientists claim that 95% of earthquakes occur in specific seismic zones.

There are two huge seismic belts on Earth that have spread thousands of kilometers along the bottom of the oceans and land. This is the meridional Pacific and the latitudinal Mediterranean-Trans-Asian.

pacific belt

The Pacific latitudinal belt encircles the Pacific Ocean to Indonesia. More than 80% of all earthquakes on the planet occur in its zone. This belt passes through the Aleutian Islands, covers the western coast of America, both North and South, reaches the Japanese Islands and New Guinea. The Pacific belt has four branches - western, northern, eastern and southern. The latter has not been studied enough. Seismic activity is felt in these places, which subsequently leads to natural disasters.

The eastern part is considered the largest in this belt. It starts in Kamchatka and ends with the South Antilles loop. In the northern part, there is constant seismic activity, which affects the inhabitants of California and other regions of America.

Mediterranean-Trans-Asian Belt

The beginning of this seismic belt is in the Mediterranean Sea. It passes through the mountain ranges of Southern Europe, through North Africa and Asia Minor, and reaches the Himalayan mountains. The most active zones in this belt are as follows:

• Romanian Carpathians;
• the territory of Iran;
• Balochistan;
• Hindu Kush.

As for underwater activity, it is recorded in the Indian and Atlantic oceans, reaching the southwest of Antarctica. The Arctic Ocean also falls into the seismic belt.

Scientists gave the name to the Mediterranean-Trans-Asian belt "latitudinal", as it stretches parallel to the equator.

seismic waves

Seismic waves are streams that originate from an artificial explosion or earthquake source. Body waves are powerful and move underground, but vibrations are felt on the surface as well. They are very fast and move in gaseous, liquid and solid media. Their activity somewhat resembles sound waves. Among them there are transverse waves or secondary ones, which have a slightly slow motion.

Surface waves are active on the surface of the earth's crust. Their movement resembles the movement of waves on water. They have destructive power, and the vibrations from their action are well felt. Among the surface waves, there are especially destructive ones that are capable of pushing rocks apart.

Thus, there are seismic zones on the surface of the earth. According to the nature of their location, scientists have identified two belts - the Pacific and the Mediterranean-Trans-Asian. In places where they lie, the most seismically active points are identified, where volcanic eruptions and earthquakes very often occur.

Secondary seismic belts

The main seismic belts are the Pacific and the Mediterranean-Trans-Asian. They encircle a significant land area of ​​our planet, have a long stretch. However, one should not forget about such a phenomenon as secondary seismic belts. There are three such zones:

• region of the Arctic;
• V Atlantic Ocean;
• in the Indian Ocean.

Due to the movement of lithospheric plates in these zones, phenomena such as earthquakes, tsunamis and floods occur. In this regard, nearby territories - continents and islands are prone to natural disasters.

So, if in some regions seismic activity is practically not felt, in others it can reach high rates on the Richter scale. The most sensitive areas are usually underwater. In the course of research, it was found that the eastern part of the planet contains the most secondary belts. The beginning of the belt is taken from the Philippines and descend to Antarctica.

Seismic region in the Atlantic Ocean

A seismic zone in the Atlantic Ocean was discovered by scientists in 1950. This area starts from the coast of Greenland, runs close to the Mid-Atlantic submarine ridge, ends in the area of ​​the Tristan da Cunha archipelago. Seismic activity here is explained by the young faults of the Seredinny Ridge, since the movements of lithospheric plates are still ongoing here.

Seismic activity in the Indian Ocean

The seismic strip in the Indian Ocean extends from the Arabian Peninsula to the south, and almost reaches Antarctica. The seismic region here is associated with the Middle Indian Range. Mild earthquakes and volcanic eruptions occur here under water, the centers are not located deep. This is due to several tectonic faults.

Seismic belts are located in close relationship with the relief, which is under water. While one belt is located in the area East Africa, the second stretched to the Mozambique Channel. Oceanic basins are aseismic.

Seismic zone of the Arctic

Seismicity is observed in the Arctic zone. Earthquakes, eruptions of mud volcanoes, as well as various destructive processes occur here. Specialists observe the main sources of earthquakes in the region. Some people believe that very low seismic activity occurs here, but this is not the case. When planning any activity here, you always need to stay alert and be prepared for various seismic events.

Seismicity in the Arctic Basin is explained by the presence of the Lomonosov Ridge, which is a continuation of the Mid-Atlantic Ridge. In addition, the regions of the Arctic are characterized by earthquakes that occur on the continental slope of Eurasia, sometimes in North America.

The location of the planetary mountain belts on Earth, as well as the plain-flat mountain belts, is not the same. The Alpine-Himalayan belt is elongated in the sublatitudinal direction, the Andean-Cordillera - in the submeridional direction, and the East Asian, as it were, borders the mainland of Asia from the east, following its bends.

The Alpine-Himalayan mountain belt begins in the southwest of Europe and stretches in a narrow strip to the east. It includes the Apennines, the Balkans, as well as in the internal depressions. One of them is a depression. The Pyrenees enclose the Meseta plateau from the northeast with a barrier almost 600 km long. This is a small mountainous country, equal in size. The width of the ridge at the base approaches 120 km. The highest point of the Pyrenees - Peak de Aneto - 3404 m. Starting at the eastern end of the Cantabrian Mountains, where they represent a single ridge, to the east the Pyrenees are divided into several parallel ridges. In its axial zone, the Pyrenees are composed of Paleozoic shales, sandstones, quartzites, limestones, and granites. On the northern and southern slopes, Paleozoic rocks are hidden under Mesozoic and Paleogene deposits. They are crumpled into folds and in some places pulled over each other. The only volcanic region of the Pyrenees is the Olot tectonic depression. The Alps are one of the largest mountainous countries this belt. Its length is about 1200 km, and the height of individual peaks exceeds 4 km (Mont Blanc - 4710 m). The mountains are strongly dissected and, like the Pyrenees, do not represent a single mountain range. Their axial zone is composed of rocks of the crystalline basement - granites, gneisses, metamorphic shales, which, approaching the margins, are replaced by sedimentary strata of clay shales of thin-layered sandstones and mudstones. From the north, the Alps are framed by low plateaus located on the site of a foothill trough; in the south, there is the Venetian-Padana depression. The eastern edge of the Alps is crossed by rift depressions that separate them from the Danubian plains. There are no volcanoes in the Alps.

The Carpathians have a length of almost 1500 km. The highest marks in the High Tatras are 2663 m. The width, however, is less than that of the Alps, but the ridges are more isolated. Intermountain basins penetrate deeply into the mountains, which are composed mainly of sandstone and clay, but in the Western Carpathians there are granites and granite gneisses. A volcanic range stretches along the southern slope of the Eastern Carpathians. The Carpathians are more fragmented than the Alps.

The Caucasian Juras are more similar to the Alps in their relief. But their morphostructures are different.

The length of the Caucasus reaches 1100 km, and the area is about 145 thousand km2. This is a mountain system consisting of longitudinal and transverse ridges, depressions elongated in one line, volcanic massifs. According to the features, the northern and southern slopes, as well as the axial strip, stand out in it.

In the axial strip are the highest mountains (4 - 5 km), composed of Precambrian and Paleozoic rocks. Their ledges are bordered by sandstones, limestones and shales of the Mesozoic age. The main Caucasian ridge is sharply dissected by deep valleys, glaciers are found on steep slopes, and the highest peak of the Caucasus and all of Europe, Mount Elbrus, is a huge volcanic cone, the height of which reaches 5633 m. The rivers are rapids, with a rapid current.

The Caucasus looks like a giant vault, broken into blocks by huge cracks. The movements of these blocks continue to this day, which often leads to collapses on the slopes.

Between the chains of grandiose mountains in this part of Europe are the Danube Plains, formed on the site of a submerged median massif. The average surface height is: at the Upper Danube Plain - 110 - 120 m, at the Middle Danube - 80 - 85 m, at the Lower Danube - 10 - 30 m.

Most of the Apennine Peninsula is occupied by the Apennine mountains. This is a system of medium-altitude ridges that rose and took shape only 800 thousand years ago. Here is the zone of the most significant earthquakes and the largest active in Europe. The highest point in the Apennines is Mount Corpo Grande (2914 m). Volcanoes are concentrated along the western coast and at the bottom of the sea: Amiata, Vulsino, Vesuvius, Etna, Vulture, etc. The largest are the Dinaric Highlands, the Albano-Pinda Mountains, the folded Stara Planina Mountains, the Rila-Rhodopi mountain range.

The Asia Minor Highlands is a continuation of the Alpine-Himalayan belt. In the north, the Pontic Range stretches in a long chain, in the south - the Taurus Mountains.

The Armenian volcanic highlands (5156 m) are located to the east of the Anatolian plateau. Here you can see volcanic plateaus, volcano cones, sinkholes and other forms of volcanic relief. In general, the Armenian Highland is a huge vault, raised and split into separate parts. The largest area of ​​the vast Iranian Highlands (5604 m) is occupied by the Elburz Range, the Zagros Mountains and the vast plains between them. This is an active seismic zone, where earthquakes of magnitude up to 10 occur.

In the southeast, the Alpine-Himalayan belt ends with the Burmese Highlands (4149 m), composed of granites, schists, limestones and sandstones. The submeridional ridges are separated here by longitudinal depressions. Axial zones are composed of Mesozoic granites and shales. It looks like the Shan Highlands.

Thus, the entire Alpine-Himalayan belt is characterized by dynamism and contrast (in the Alps, the range of motion was 10–12 km; in the Carpathians, 6–7 km; in the Himalayas, 10–12 km). Although not developed in all of this belt, but the seismic intensity is quite high. Zones of "seismic silence" alternate with zones of frequent strength up to 10 points.

The Andean-Cordillera mountain belt, with a width of 600 to 1200 km, stretches for 18 thousand km. It starts in Alaska and goes along the western coasts and. The mountains and plateaus of Alaska are diverse. The coastal plains are separated from the interior by high ridges, the Yukon Plateau is divided into sections by intermountain depressions, and the Brooks Ridge separates the Yukon from the ice of the ocean in the north with an impenetrable wall. The geological structure of this territory involves rocks of the Precambrian, Paleozoic and Mesozoic ages. They are, as a rule, crumpled into folds and displaced along thrust zones. The east of Alaska is characterized by deep longitudinal ditches, stretching far to the south.

The Rocky Mountains are a chain of high parallel ridges and mountain ranges, stretching for 3200 km. The width of the chain is significant (400 - 700 km), although not constant. The thickness of the earth's crust is about 40 km. The mountains reach a height of 4399 m. The tectonic and geological structures of the Rocky Mountains in the north and south differ markedly. Deep ditches and blocky massifs are visible in the north. Rift formations are widespread in the central and especially in the southern part of the Rocky Mountains. Until now, one of the mysteries remains the origin of the giant Rocky Mountain Moat - a narrow (about 6-12 km) crack, stretched along the western slope of the mountains for 15 thousand km. From ruptures in the rock mass, it is possible to establish thrusts of the Precambrian sequences on the Mesozoic rocks. The enormous length of the Ditch can only be explained by tectonic extensions of the earth's crust. In the central part, the main range is about 300 km wide. The southern part of the Rocky Mountains differs sharply from the northern and central parts.

Between the Rocky Mountains and the sea coast are inland plateaus, mountains and plateaus. They include the Stikine Plateau, the Nechaco-Fraser Plateau, the Columbian Plateau, the Colorado Plateau, and the Range and Basin Province. The interior plateaus and plateaus are characterized by undulating relief with mountains. The Columbian Plateau (200 - 1000 m) is composed mainly of volcanic rocks; Colorado - horizontally deposited strata of sedimentary rocks and only the province of the Ranges and Basins is a unique territory with an unusual relief. Its average height is 1400 - 1700 m, the maximum is 4356 m. In its relief, the Mexican Highlands differ from the Rocky Mountains and the interior plains. This is a mountainous area with disjointed ridges 600 - 1000 m high. Some of them reach 2500 m. There are extensive plateaus and volcanic massifs. Among the most famous volcanoes are Popocatepetl (5452 m) and Orizaba (5747 m). They are distinguished by well-defined conical arrays. In the coastal zone there are high ridges and deep depressions, and the relief is less contrasting, although it is here that the highest point in America - the mountain (6193 m) is located. A characteristic feature of the relief is the exceptional fragmentation of blocks, the linear arrangement of ridges and depressions.

The differences in the large features of the relief of this part of the Andean-Cordillera mountain belt are primarily due to the history of their formation. The mountain ranges of the Rocky Mountains formed at the end of the Mesozoic, when low plains still existed on the site of internal plateaus and plateaus. Fragmented, but less tectonically active morphostructures of the Rocky Mountains already about 10 million years ago turned into large linear ridges and depressions, and then into a system of alternating volcanic ridges and plateaus, blocky mountains, and slit-like ditches. The narrow and long isthmus connecting North and South is called Central America. It is characterized by many volcanic massifs and ridges, lava plateaus and plateaus. A dense network of faults permeates the entire region. The Andean-Cordillera belt continues in South America. The most characteristic feature of the Andes located here is a branched system of ridges called. They stretch almost parallel to each other and are separated by deep depressions, high plateaus and plateaus. The highest mountain range is crowned by Mount Akonkagau (6980 m).

On both sides of the Andes there are linear troughs. They have different origins. In the north, the belt begins with a sublatitudinal strip of the Venezuelan Andes, which are replaced by the Colombian Andes without sharp transitions. The largest ranges here are the Western, Central and Eastern Cordillera, as if diverging in rays from one node in the region of the Cumbal massif in the south. The Ecuadorian-Peruvian Andes, located to the south, are only 320-350 km wide. There are no curving mountain ranges. The average height reaches 4 - 5 km, and the highest marks are the volcanic massifs of Chimborazo (6272 m) and Cotopaxi (5896 m). In this area, the so-called alley of volcanoes is clearly expressed in the relief - the bottom of a large graben filled with ash-sand and rubble deposits and framed on both sides by chains of volcanic cones. In the south of Peru, the uplift of intermountain basins led to the formation of huge plateaus.

If you move to the Andes from the side Pacific Ocean, then the Andes mountain range arises somehow immediately, without a gradual rise. The path is blocked by gorges with turbulent streams, the slopes become very steep, covered with yellow spots of fresh and landslides. There are practically no river terraces in the valleys.

Here you can start climbing the Western Cordillera. Steep slopes go up, the road meanders, adapting to the terrain. And now dry steppes appear on both sides of the road, between the curtains of grasses the dried earth is clearly visible. On the cones of volcanoes grow, which at first do not make much impression - there is simply nothing to compare them with. Suddenly, the road begins to descend, and the traveler finds himself at the bottom of a vast depression, occupied by numerous villages, fields, and pastures. This depression is called differently - the alley of volcanoes, intra-Andean depression, a strip of giant grabens. The depression is bordered on both sides by the mountain ranges of the Western and Eastern Cordilleras, its width reaches 40 km.
For the inhabitants of the temperate zone, such relief and landscapes are in many ways unusual. In and Peru they are called paramo. i.e. high-altitude flat dry steppes. Paramo occupies between 2800 and 4700 m. The hilly plains here are combinations of surfaces composed of volcanic ash and debris thrown out at. You can clearly see the stripes of lahars - frozen hot streams.

In the geological section, the landscapes of paramo are a “layer cake”, consisting of different rocks and preserving the memory of the cataclysms of the past.

Not studied as well as on land. In the largest oceans - the Pacific and Atlantic, stretching on both sides of the equator, the relief cannot even be compared with the most significant mountain belts on land. The Pacific Ocean is surrounded on the north, west, and southwest by marginal seas that jut deep into the continents. The main bottom morphostructures are mid-ocean ridges and submarine basins with mountainous and flat relief.

The mid-ocean ridges of the Pacific Ocean stretch for many thousands of kilometers and in some places take the form of wide and extended hills, which are often broken by transform faults into segments of different sizes and different ages. The planetary system of mid-ocean ridges and uplands in the Pacific Ocean is represented by wide and poorly dissected South Pacific and East Pacific Rise. Not far from the Gulf of California, the East Pacific Rise comes close to the North American continent. At this ridge, rifts are weakly expressed, and in some places are absent. In the relief, domed hills are traced more often, spaced from each other by 200 - 300 km.

Mountain structures in other parts of the Pacific Ocean are represented by arched blocky ridges, which sometimes have arched outlines. For example, the northern arc forms the Hawaiian volcanic range. The island of Hawaii is the top of a volcanic massif rising above the water from shield underwater volcanoes that have merged with their bases. To the south of the Hawaiian Ridge there is a mountain system, the length of which reaches 11 thousand km. In different areas it has various titles. These seamounts begin from the Cartographers massif, then pass into the Markus-Necker mountains and are further represented by underwater ridges near the Line and Tuamotu Islands. This mountain system goes almost to the base of the East Pacific Rise. According to scientists, all these mountains are fragments of the former mid-ocean ridge.

The huge Northeast Basin at the bottom of the Pacific Ocean lies at a depth of about 5 km (its maximum depth is 6741 m). Hilly relief prevails at the bottom of the basin.

Planetary landforms also include - the second in size and depth among the oceans of the Earth. It stretches from to . The planetary is the Mid-Atlantic Ridge, which is divided into three ridges: Reykjanes, North Atlantic and South Atlantic. The Reykjanes Range can be traced from the island to the south. The Russian scientist O. K. Leontiev believed that this was not even a ridge, but a highland with well-defined axial and flank zones. The North Atlantic Ridge is divided into many segments by transform faults, and deep grabens are noted at their intersection, often much deeper than the axial rift basin. The South Atlantic Ridge has a meridional strike and is divided into segments by the same faults. The bed of the Atlantic Ocean does not contain particularly large submarine basins, but plateaus and mountains are common. One of the largest underwater basins is the North American. Three flat plains were found within its limits.

The system of mid-ocean ridges in the third largest ocean of the Earth differs from similar ridges in the Atlantic Ocean in that they consist of separate links (Arabian-Indian, West Indian, Central Indian ridges; Australo-Antarctic Rise), which, as would converge at one point. Inside such a node is a deep canyon, which gradually expands and leads to the disintegration of seamounts into separate parts. At the bottom of the Indian Ocean there are and. The bottom in them is lowered to a depth of 5 - 6 km. In the relief of the Western Australian Basin (-6429 m), underwater ridges and hills are well expressed. In the largest Central Basin (-5290 m) at the bottom there is an inclined surface of an accumulative plume with distinct hollows - traces of turbidity flows. But in the middle of a gentle plume, there are also mountains 3-3.5 km high. In the northeastern part of the ocean, there is the East Indian underwater ridge, about 4800 km long and about 4000 m in relative height. Young sediments are almost absent on the steep slopes of this ridge, and the ancient sedimentary cover contains igneous bodies inside. The ridge was formed at the site of a large meridional fault in the earth's crust about 75 million years ago (i.e., in the Late Cretaceous). Powerful outpourings of volcanic lavas repeatedly led to the appearance of the peaks of the ridge in the form of islands that towered above the surface of the ocean. Following the "plate" theory, the mid-ocean ridges in the Indian Ocean are the boundaries of the African, Indo-Australian and Antarctic lithospheric plates. The bottom itself is the result of the spreading of these plates.

In the Arctic region of the Northern Hemisphere is located - relatively small in size. Its area is about 13.1 million km2, and the average depth is 1780 m. In addition, there are numerous marginal seas and the vast underwater plains of the continental shelves. The width of some of the shelves reaches 1300 km. These are the largest shallow plains on our planet. Characteristically, there are no deep-sea trenches in the Arctic Ocean. At the point, the depth of the ocean is about 4400 m.

Alpine folding is an epoch in the history of the formation of the earth's crust. In this era, the highest mountain system in the world, the Himalayas, was formed. What characterizes the era? What other mountains alpine folding exist?

Folding of the earth's crust

In geology, the word "fold" is not far from its original meaning. It denotes a section of the earth's crust in which the rock is "crumpled". The rock usually occurs in horizontal layers. Under the influence of the internal processes of the Earth, its position can change. It bends or squeezes, overlapping adjacent areas. This phenomenon is called folding.

The formation of folding occurs unevenly. The periods of their appearance and development are named in accordance with geological epochs. The most ancient is the Archean. It finished forming 1.6 billion years ago. Since that time, numerous external processes of the planet have turned it into plains.

After the Archean, there were Baikal, Caledonian, Hercynian. The most recent is the Alpine epoch of folding. In the history of the formation of the earth's crust, it occupies the last 60 million years. The name of the era was first announced by the French geologist Marcel Bertrand in 1886.

Alpine folding: characteristics of the period

The era can be roughly divided into two periods. In the first, deflections actively appeared in the earth's surface. Gradually they were filled with lava and sedimentary deposits. The uplifts of the crust were small and very localized. The second stage was more intensive. Various geodynamic processes contributed to the formation of mountains.

Alpine folding has formed most of the largest modern mountain systems that are part of the Mediterranean and Pacific volcanic rings. Thus, folding forms two large areas with mountain ranges and volcanoes. They are part of the youngest mountains on the planet and differ in climatic zones, as well as heights.

The era has not yet ended, and the mountains continue to form even now. This is evidenced by seismic and volcanic activity in various regions of the Earth. The folded area is not continuous. The ridges are often interrupted by depressions (for example, the Fergana depression), in some of them seas have formed (Black, Caspian, Mediterranean).

mediterranean belt

Mountain systems of Alpine folding, which belong to the Alpine-Himalayan belt, stretch in a latitudinal direction. They almost completely cross Eurasia. They start in North Africa, pass through the Mediterranean, Black and Caspian Seas, stretching through the Himalayas to the islands of Indochina and Indonesia.

The mountains of Alpine folding include the Apennines, Dinars, Carpathians, Alps, Balkans, Atlas, Caucasus, Burma, Himalayas, Pamirs, etc. All of them differ in their appearance and height. For example, - medium-high, have smooth outlines. They are covered with forests, alpine and subalpine vegetation. The Crimean mountains, in contrast, are steeper and more rocky. They are covered with more stingy steppe and forest-steppe vegetation.

The highest mountain system is the Himalayas. They are within 7 countries including Tibet. The mountains stretch for 2,400 kilometers in length, and their average heights reach 6 kilometers. The highest point is Mount Everest with a height of 8848 kilometers.

Pacific ring of fire

Alpine folding is also associated with the formation of the Ono and includes the depressions that are adjacent to them. The volcanic ring is located along the perimeter of the Pacific Ocean.

It covers Kamchatka, the Kuril and Japanese Islands, the Philippines, Antarctica, New Zealand and New Guinea on the west coast. On the eastern coast of the ocean, it includes the Andes, the Cordilleras, the Aleutian Islands and the Tierra del Fuego archipelago.

The name "ring of fire" this area has earned due to the fact that most of the world's volcanoes are located here. Approximately 330 of them are active. In addition to eruptions, the largest number of earthquakes occur within the Pacific belt.

Part of the ring is the longest mountain system on the planet - the Cordillera. They cross 10 countries that are part of the Northern and South America. The length of the mountain range is 18 thousand kilometers.