The lithosphere is the outer solid shell of the Earth, including the earth's crust and the upper part of the mantle. The lithosphere includes sedimentary, igneous and metamorphic rocks. The lower boundary of the lithosphere is indistinct and is determined by a decrease in the viscosity of the medium, the speed of seismic waves and an increase in thermal conductivity. The lithosphere covers the earth's crust and the upper part of the mantle several tens of kilometers thick to the asthenosphere, in which the plasticity of rocks changes. The main methods for determining the boundary between the upper boundary of the lithosphere and the asthenosphere are magnetotelluric and seismological. The thickness of the lithosphere under the oceans is from 5 to 100 km (the maximum value is at the periphery of the oceans, the minimum is under the Mid-ocean ridges), under the continents - 25-200 km (maximum - under ancient platforms, at least - under relatively young mountain ranges, volcanic arcs). The structure of the lithosphere under the oceans and continents has significant differences. Beneath the continents in structure earth's crust The lithosphere distinguishes sedimentary, granite and basalt layers, the thickness of which as a whole reaches 80 km. Beneath the oceans, the Earth's crust has repeatedly undergone partial melting processes during the formation of the oceanic crust. Therefore, it is depleted in fusible rare compounds, devoid of a granite layer, and its thickness is much less than that of the continental part of the earth's crust. The thickness of the asthenosphere (a layer of softened, doughy rocks) is about 100-150 km. Currently, on the ocean floor in the middle ridges, the process of formation of the earth's crust continues, which is accompanied by the release of gases and small volumes of water. Oxygen is present in high concentrations in the composition of the modern earth's crust, followed by silicon and aluminum in percentage. Basically, the lithosphere is formed by compounds such as silicon dioxide, silicates, aluminosilicates. In the formation of most of the lithosphere took part crystalline substances magmatic origin. They were formed during the cooling of magma that came to the surface of the Earth, which is in the bowels of the planet in a molten state. In cold regions, the thickness of the lithosphere is the greatest, and in warm regions it is the smallest. The thickness of the lithosphere can increase with a general decrease in the heat flux density. Upper layer the lithosphere is elastic, and the lower one is plastic in the nature of the reaction to constantly acting loads. In tectonically active areas of the lithosphere, horizons of reduced viscosity are distinguished, where seismic waves travel at a lower speed. According to scientists, according to these horizons, some layers “slip” in relation to others. This phenomenon is called stratification of the lithosphere. In the structure of the lithosphere, mobile areas (folded belts) and relatively stable areas (platforms) are distinguished. Blocks of the lithosphere (lithospheric plates) move along the relatively plastic asthenosphere, reaching sizes from 1 to 10 thousand kilometers in diameter. At present, the lithosphere is divided into seven main and a number of small plates. The boundaries separating the plates from each other are the zones of maximum volcanic and seismic activity.

Theme "Lithosphere"

in 7th grade

K.S. LAZAREVICH

How to conduct literate,
interesting and meaningful lessons
on upcoming topics

The boundaries of the lithosphere

The course of geography in the 7th grade begins with the fact that students return to topics that seemed to be studied in the 6th grade - the lithosphere, atmosphere, hydrosphere. This beginning of the course already shows how unreliable, unsteady the knowledge gained in the first year of geography. And for the 7th grade, these topics are quite complicated, but there is no need to talk about the 6th grade. We will try to analyze the difficulties that are encountered in the first topics of the 7th grade. At the same time, we will return to the textbooks of the previous year of study, clarify and correct some of the provisions found there.

Term lithosphere has been used in science for a long time - probably since the middle of the 19th century. But contemporary meaning he acquired less than half a century ago. Even in the geological dictionary of the 1955 edition it is said:
LITHOSPHERE - the same as Earth's crust.
In the dictionary of the 1973 edition and in subsequent ones we already read:
The LITHOSPHERE ... in the modern sense includes the earth's crust ... and the rigid upper part of the Earth's upper mantle.

We draw the reader's attention to the wording: the upper part of the upper mantle. Meanwhile, in one of the textbooks in the figure it is indicated: "The lithosphere (the earth's crust and upper mantle)", and according to the figure it turns out that the entire mantle, which is not part of the lithosphere, is lower (Krylova 6, p. 50, fig. 30 ). By the way, in the same textbook in the text (p. 49) and in the textbook for the 7th grade (Krylova 7, p. 9) everything is correct: it is said about the upper part of the mantle. Upper mantle is a geological term for a very large layer; the upper mantle has a thickness (thickness) of up to 500, according to some classifications - over 900 km, and the lithosphere includes only the upper ones from several tens to two hundred kilometers. All this is difficult not only for students, but also for teachers. It would be better to abandon the term at school altogether lithosphere, limiting itself to mentioning the earth's crust; but here lithospheric plates arise, and there is no way without the lithosphere. Perhaps rice will help. 1, it is easy to redraw it in an enlarged form. Speaking of the lithosphere, one must firmly remember that it includes the earth's crust and the upper, relatively thin layer of the mantle, but not the upper mantle- the last term is much broader.

Layers of the lithosphere

The earth's crust, with tenacity worthy of a better application, is continued in all textbooks to be divided into three layers - sedimentary, granite and basalt. And it's time to change the record.
Most of the information about the deep structure of the Earth was obtained from indirect, geophysical data - from the propagation velocities of seismic waves, from changes in the magnitude and direction of gravity (insignificant, perceptible only by very accurate instruments), from magnetic properties and the magnitude of the electrical conductivity of rocks. The mass of dense rocks in the same volume is greater than less dense rocks, they create an increased gravitational field. In dense rocks, shock waves travel faster (recall that sound travels noticeably faster in water than in air). Passing through rocks with different physical properties and, waves are reflected, refracted, absorbed. Waves are transverse and longitudinal, the speed of their propagation is different. Explore the passage of natural shock waves during earthquakes, create these waves artificially, producing explosions.
From all these data, a picture of the distribution over the area and in depth of rocks with different physical properties is formed. On its basis, a model of the structure of the Earth's interior is created: they select rocks, whose physical properties more or less coincide with those determined by indirect methods, and mentally place these rocks at the appropriate depth. When it is possible to drill a well to a depth previously inaccessible, or to obtain some other reliable data, this model is confirmed in whole or in part. It happens that it is not confirmed at all, you have to build a new one. After all, it is by no means excluded that rocks lie at depth that we do not meet on the surface at all, or that at depth, at high temperature and pressure, the properties of rocks well known to us will change beyond recognition.
In 1909, the Serbian geophysicist Andrei Mohoro'vich noticed that at a depth of 54 km, the velocities of seismic waves increase sharply, abruptly. Subsequently, this jump was traced throughout the globe at depths from 5 to 90 km and is now known as the Mohorovichich boundary (or surface), in short, the Moho boundary, even shorter, the M boundary. The M surface is considered the lower boundary of the earth's crust. Important feature this surface is that it is in in general terms is, as it were, a mirror image of the relief of the earth's surface: it is higher under the oceans, lower under the continental plains, under the most high mountains falls below everything (these are the so-called mountain roots).
This feature of the earth's crust, probably, will not be difficult to explain to schoolchildren by letting several pieces of wood of different shapes, preferably heavy, so that they go into the water by 2 / 3 - 3 / 4, float in a transparent vessel with water; those of them that protrude above the water will also be deeper submerged (Fig. 2).

Rice. 2. Experience explaining the ratio between the upper and lower boundaries of the earth's crust

According to the traditional concept of the structure of the earth's crust, which can be read in any textbook, it is customary to distinguish three main layers in the composition of the earth's crust. The upper of them is composed mainly of sedimentary rocks and is called sedimentary. The two lower layers are called "granite" and "basalt". Accordingly, two types of the earth's crust are distinguished. continental crust contains all three layers and has a thickness of 35-50 km, under the mountains up to 90 km. In the oceanic crust, the sedimentary layer has a much smaller thickness, and the middle, "granite" layer is absent; the thickness of the oceanic crust is 5–10 km (Fig. 3). Between the "granite" and "basalt" layers lies the Konrad boundary, named after the Austrian geophysicist who discovered it; it is not mentioned in school textbooks.

But research over the past two decades has shown that this well-proportioned, easy-to-remember scheme does not fit well with reality. "Granite" and "basalt" layers consist mainly of igneous and metamorphic rocks. At the Konrad boundary, there is an abrupt increase in seismic wave velocities. Such an increase in velocities can be expected during the transition of waves from rocks with a density of 2.7 to rocks with a density of 3 g/cm 3 , which approximately corresponds to the densities of granite and basalt. Therefore, the overlying layer was called "granite", and the underlying "basalt". But note: these names are in quotation marks everywhere. Geophysicists did not consider these layers to be composed of granite and basalt, they only talked about some analogy. However, even many geologists could not resist the temptation to believe that the "granite" layer is really from granite, and the "basalt" layer is from basalt. What can we say about the authors of school textbooks!
Korinskaya, p. 20, fig. 8. Signatures to the conventional signs: “A layer of sedimentary rocks. layer of granite. layer of basalt.
Petrova, p. 47-48. “We are entering the granite layer of the Earth. Granite ... was formed from magma in the thickness of the earth's crust ... We are entering a layer of basalt - a rock of deep origin. (By the way, this is not true: basalt is not deep, but outflowing rock.)
Finarov, p. 15 and Krylova 7, p. 10, fig. 1 - the granite and basalt layers are named without quotes, and the student clearly sees that they consist of these rocks.
The necessary reservation is made only in one textbook, but is it sufficient to draw attention to it?
“In the mainland [crust] lies a layer called granite. It is composed of igneous and metamorphic rocks, similar in composition and density to granites ... The lower layer of the earth's crust is a layer conventionally called basalt; it ... consists of rocks whose density is close to that of basalts” (Krylova, Gerasimova, p. 10).
One of the tasks of the Kola superdeep well was to reach the Konrad boundary, which, according to geophysical data, lies in this place at a depth of 7-8 km. And perhaps the most important geological result of drilling was the proof of the absence of the Konrad boundary in its geological understanding: in which rocks the well went above the boundary established by geophysicists, in the same rocks it passed several kilometers below it.

And the geophysical fate at the Konrad boundary turned out to be not as glorious as that at the Mohorovichich boundary. In some places it was singled out confidently, in other places - less confidently (whether she was alone, or not alone), somewhere they were not found at all. There was a need to abandon the terms "granite layer" and "basalt layer", even if in quotation marks, and to recognize that the Conrad boundary does not exist. Modern model The structure of the earth's crust looks much more complicated than the classical three-layer structure (Fig. 4). It still has continental and oceanic crust. Characteristic features the continental crust can be considered a significant (tens of kilometers) thickness, an increase in density from top to bottom - gradual or spasmodic; the sedimentary layer within the continental crust is usually thicker than within the oceanic one. The oceanic crust is much thinner, more homogeneous in composition; in relation to it, one can speak of a basalt layer without quotes, since the ocean floor is composed mainly of basalts.

For more details see: I.N. Galkin. Into the ocean behind the bark//Geography, No. 42/97, p. 6-7, 13.
** For more details see: T.S. Mints, M.V. Mints. Kola Superdeep//Geography, No. 33/99, p. 1-4.

Theory of lithospheric plates

This theory is usually very attractive to students. She is elegant and seems to explain everything. Many of the perplexities that arise among scientists in connection with it relate to issues so complex that it is not even worth talking about them at school (for example, which of the non-specialists will be able to assess the legitimacy of the doubts that arise in connection with the redistribution of the heat flux from the bowels of the Earth to the surface? ). But students must be told that there are unresolved problems in this theory, which, perhaps, will force them to reconsider it - most likely not entirely, but in some details.
According to the texts of textbooks, schoolchildren can conclude that plate tectonics is a refinement of Alfred Wegener's hypothesis, which peacefully replaced it. Actually it is not. Wegener has continents composed of a relatively light substance, which he called sial(silicium-aluminum), as if floating on the surface of a heavier substance - sima(silicium-magnesium). At first, the hypothesis captivated almost everyone, it was accepted with enthusiasm. But after 2-3 decades, it turned out that the physical properties of the rocks do not allow such navigation, and a fat cross was put on the theory of continental drift. And as often happens, the baby was thrown out with the water: the theory is bad, which means that the continents cannot move at all. Only by the 60s, that is, only 40-45 years ago, when the global system of mid-ocean ridges had already been discovered, they built an almost new theory, in which only a change in the relative position of the continents remained from Wegener's hypothesis, in particular, an explanation of the similarity of the outlines of the continents on both sides of the Atlantic.
The most important difference between modern plate tectonics and Wegener's hypothesis is that Wegener continents moved along the substance that made up the ocean floor, in the modern theory plates are involved in the movement, which include areas of both land and the ocean floor; The boundaries between plates can run along the bottom of the ocean, and on land, and along the boundaries of continents and oceans.
Motion lithospheric plates occurs along the asthenosphere - the layer of the upper mantle, which underlies the lithosphere and has viscosity, plasticity. It was not possible to find mention of the asthenosphere in the texts of textbooks, but in one textbook, not only the asthenosphere, but also “the layer of the mantle above the asthenosphere” is signed on the figure (Finarov, p. 16, Fig. 4). You should not mention the asthenosphere in the lessons, the structure upper layers Earth is already difficult enough.
The textbooks explain that along the axes of the mid-ocean ridges, the areas of lithospheric plates gradually increase. This process has been named spreading(English spreading expansion, distribution). But the surface the globe cannot increase. The emergence of new sections of the earth's crust on the sides of the mid-ocean ridges must be compensated for by its disappearance somewhere. If we believe that lithospheric plates are sufficiently stable, it is natural to assume that the disappearance of the crust, like formation of a new, should occur at the boundaries of converging plates. In this case, there can be three different cases:
- two parts of the oceanic crust are approaching;
- a section of the continental crust is approaching a section of the oceanic;
- two sections of the continental crust are approaching.
The process that occurs when parts of the oceanic crust approach each other can be schematically described as follows: the edge of one plate rises somewhat, forming an island arc; the other goes under it, here the level of the upper surface of the lithosphere decreases, and a deep-water oceanic trench is formed. Such are the Aleutian Islands and the Aleutian Trench framing them, Kurile Islands and the Kuril-Kamchatsky Trench, the Japanese Islands and the Japanese Trench, the Mariana Islands and the Mariana Trench, etc.; all this in pacific ocean. In the Atlantic - the Antilles and the Puerto Rico Trench, the South Sandwich Islands and the South Sandwich Trench. The movement of plates relative to each other is accompanied by significant mechanical stresses, therefore, in all these places, high seismicity and intense volcanic activity are observed. The sources of earthquakes are located mainly on the surface of contact between two plates and can be at great depths. The edge of the plate, which has gone deep, plunges into the mantle, where it gradually turns into mantle matter. The subducting plate is heated, and magma is melted out of it, which erupts in island arc volcanoes (Fig. 5).

The process of submerging one plate under another is called subduction(literally - pushing). This Latin term, like the above English word"spreading" is widespread, both are found in popular literature, so teachers need to know them, but it hardly makes sense to introduce them in a school course.
When sections of the continental and oceanic crust move towards each other, the process proceeds approximately the same as in the case of a meeting of two sections of the oceanic crust, only instead of an island arc, a powerful chain of mountains is formed along the coast of the mainland. The oceanic crust is also submerged under the continental edge of the plate, forming deep-sea trenches, volcanic and seismic processes are just as intense. Magma that does not reach the earth's surface crystallizes, forming granitic batholiths (Fig. 6). A typical example is the Cordillera of Central and South America and the system of trenches running along the coast - Central American, Peruvian and Chilean.

When two sections of the continental crust approach each other, the edge of each of them experiences folding, faults, mountains are formed, and seismic processes are intense. Volcanism is also observed, but less than in the first two cases, since the earth's crust in such places is very thick (Fig. 7). This is how the Alpine-Himalayan mountain belt was formed, stretching from North Africa and the western extremity of Europe across all Eurasia to Indochina; it includes the highest mountains on Earth, high seismicity is observed along its entire length, and there are active volcanoes in the west of the belt.
Several textbooks contain diagrams of the position of the continents so many millions of years ago.

In one book (Krylova 7, p. 21, fig. 12) the location of the continents after 50 million years is given. If this textbook is used, it would be worth commenting on the scheme, saying beforehand that this is only a forecast, very approximate, which will be justified only if general direction plate movements, there will be no major restructuring of them. The forecast is for a significant expansion Atlantic Ocean, East African Rifts (they will be filled with the waters of the World Ocean) and the Red Sea, which will directly connect the Mediterranean Sea with the Indian Ocean.

Thus, when checking whether schoolchildren remember well the topic “Lithosphere” in the 6th grade, it is necessary to simultaneously dispel some misconceptions that could arise. If you want to give students the basics of knowledge at a modern level, you will have to, while explaining new, more complex material, abandon the presentation of outdated information given in textbooks.
Here are the main theses that need to be stated and explained.
1. The lithosphere includes the earth's crust and the upper, relatively small part of the mantle.
2. The earth's crust is of two types - continental and oceanic.
3. The continental crust has a significant (tens of kilometers) thickness, its density increases downwards. The crust consists of sedimentary rocks (usually at the top), below are igneous and metamorphic rocks of various compositions.
4. The thickness of the oceanic crust is 5-10 km, it is composed mainly of basalts.
(When explaining the structure of the continental and oceanic crust, the "granite" and "basalt" layers, and even more so the Konrad boundary, should not be mentioned.)
5. The theory of plate tectonics came to replace Wegener's hypothesis only after the hypothesis was completely rejected.
6. According to Wegener's hypothesis, the continents moved along the denser matter that makes up the ocean floor.
7. According to the theory of lithospheric plates, large areas of the lithosphere with continental crust, or oceanic, or both, are involved in the movement.
Various types of interaction of lithospheric plates with different types the earth's crust, the teacher may or may not consider depending on the degree of preparedness of the class. These examples are interesting and can be illustrated in physical map world, but they are not included in the mandatory program.

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Korinskaya - V.A. Korinskaya, I.V. Dushina, V.A. Shchenev. Geography of continents and oceans: Proc. for 7 cells. avg. school - M.: Enlightenment, 1993. - 287 p.
Krylova 6 - O.V. Krylov. physical geography: Start course: Proc. for 6 cells. general education institutions. - M.: Enlightenment, 1999 (and subsequent editions). - 192 p.
Krylova 7 - O.V. Krylov. Continents and oceans: Proc. for 7 cells. general education institutions. Moscow: Education, 1999 (and subsequent editions). - 304 p.
Krylova, Gerasimova - O.V. Krylova, T.P. Gerasimov. Geography of continents and oceans: Prob. textbook for 7 cells. general education institutions. - M.: Enlightenment, 1995. - 318 p.
Petrova - N.N. Petrov. Geography. Initial course. Grade 6: Proc. for general education textbook establishments. - M.: Bustard; DiK, 1997. - 256 p.
Finarov - D.P. Finarov, S.V. Vasiliev, Z.I. Shipunova, E.Ya. Chernikhov. Geography of continents and oceans: Proc. for 7 cells. general education institutions. - M.: Enlightenment, 1996. - 302 p.

Volcanoes are geological formations having a cone-shaped or domed shape. Volcanoes about which there is historical evidence of eruption are called active, those about which there is no information are called extinct.

Geochronology- designation of the time and sequence of formation of rocks. If the occurrence of rocks is not disturbed, then each layer younger than that on which it rests. The upper layer was formed later than all those lying below. The oldest interval of geological time, including the Archean and Proterozoic, is called the Precambrian. It covers almost 90% of all geological history Earth.

In the geological history of the Earth, several epochs of intense mountain building (folding)- Baikal, Caledonian, Hercynian, Mesozoic, Cenozoic.

The mountains- areas of the earth's surface with large sharp fluctuations in altitude. By absolute height, high mountains (above 2000 m), medium (from 1000 to 2000 m), low (up to 1000 m) are distinguished.

Earth's crust (ZK)- the upper solid layered shell of the Earth, heterogeneous and complex, its thickness ranges from 30 km (under the plains) to 90 km (under the high mountains). There are two types of the earth's crust - oceanic and continental (mainland). The continental crust has three layers: the upper - sedimentary (the youngest), the middle - "granite" and the lower - "basalt" (the oldest). Its thickness reaches 70 km under mountain systems. The oceanic crust has a thickness of 5-10 km, consists of "basalt" and sedimentary layers, it is heavier than the continental one.

Lithosphere- the stone shell of the Earth, which includes the earth's crust and the upper part of the mantle and consists of large blocks - lithospheric plates. Lithospheric plates can carry continents and oceans, but their boundaries do not coincide. Lithospheric plates move slowly, mid-ocean ridges are formed along the faults, in the axial part of which there are rifts.

Minerals- combinations of different chemical elements, which form natural bodies homogeneous in physical properties. Rocks are composed of minerals, which differ in origin.

uplands- vast mountainous areas, characterized by a combination of mountain ranges and leveled areas located high above sea level.

Island- a small (compared to the mainland) piece of land, surrounded on all sides by water. An archipelago is a group of islands. By origin, the islands are continental (located on the shelf), volcanic and coral (atolls). The largest islands are mainland. Coral islands are located in the tropical zone, since warm salt water is necessary for the life of corals.

Platform- a vast, sedentary and most stable part of the earth's crust, in the relief they are usually expressed as plains. Continental platforms have a two-tier structure: a foundation and a sedimentary cover. The areas where the crystalline basement comes to the surface are called shields. There are ancient (Precambrian basement) and young (Paleozoic or Mesozoic basement) platforms.

Peninsula- a piece of land that extends into the sea.

Plain- a vast area of ​​the earth's surface with small fluctuations in heights and slight slopes, confined to stable tectonic structures. According to the absolute height among the plains, lowlands (up to 200 m above sea level), highlands (from 200 to 500 m), plateaus and plateaus (over 500 m) are distinguished. By the nature of the relief, flat and hilly plains are distinguished.

The relief of the bottom of the oceans- landforms of the surface of the ocean floor, developed within various types earth's crust. The first zone - the underwater margin of the continents (represented by the continental type of ZK) - consists of a shelf (up to 200 m), a relatively steep continental slope (up to 2500 m), passing into the continental foot. The second zone - transitional (at the junction of the continental and oceanic zones) - consists of marginal seas, volcanic islands and deep sea trenches. The third is an ocean bed with an oceanic-type SC. The fourth zone stands out in the central parts of the ocean - these are the mid-ocean ridges.

Relief- this is a set of forms of the earth's surface, different in outline, origin, age and history of development. It is formed under the influence of internal and external factors.

seismic belts- places of collision of lithospheric plates. In the process of their collision, the heavier ones (with the oceanic crust) sink under the less heavy ones (with the continental crust). Deep-water trenches form at the bends of the downward-sloping plate, and mountain building occurs at the edge (mountains appear on the continents, and islands appear in the oceans). Mountain building also occurs in places where plates collide with the same continental crust.

Exogenous processes(external) - geological processes occurring on the surface and in upper parts the earth's crust under the influence solar energy and gravity.

Endogenous processes(internal) - geological processes occurring in the bowels of the earth and due to its internal energy. They appear in the form tectonic movements, seismic processes (earthquakes), volcanism.

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Archived: three lessons in geography on the topic "Lithosphere"

"lithosphere_plate"

The lithospheric plate is a large stable area of ​​the earth's crust, part of the lithosphere. According to the theory of plate tectonics, lithospheric plates are limited by zones of seismic, volcanic and tectonic activity - plate boundaries.

The division of the earth's crust into plates is not unambiguous, and as geological knowledge accumulates, new plates are distinguished, and some plate boundaries are recognized as non-existent.

A. Wegener came up with the idea of ​​a possible movement of the continents, when he carefully considered geographical map peace. He was struck by the amazing similarity of the outlines of the coasts of South America and Africa.

The formation and movement of plates is associated with the mixing of the mantle substance due to the temperature difference in its upper and lower parts.

Plate boundaries are three types: divergent, convergent and transform.

There are three types of plate boundaries: divergent, convergent, and transform.

Formation of mountains and mid-ranges

Plate displacement during earthquakes

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"Storage. belt"

Horst - an elevated, usually elongated section of the earth's crust, formed as a result of tectonic movements.

Graben - a section of the earth's crust, lowered relative to the surrounding area along tectonic faults.

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"Ancient Continents"

ancient continents

Geography of continents and oceans

The history of the formation of the Earth's relief

Since the formation of the Earth - 4.6 billion years ago - the appearance of its surface has changed many times: the continents and oceans have acquired different sizes and outlines. Contemporary geographical position continents and oceans, the features of their relief are the result of a long geological development Earth.

Pangea, 200 million years ago

Pangea is the name given Alfred Wegener proto-continent that arose in the Paleozoic era.

Ancient continent and ocean

In the process of the formation of Pangea from more ancient continents, mountain systems arose at the places of their collision, some of which have existed to this day, for example, the Urals or the Appalachians. These early mountains are much older than these comparatively young ones. mountain systems like the Alps in Europe, the Cordillera in North America, the Andes in South America or the Himalayas in Asia. Due to the erosion that lasts for many millions of years, the Urals and the Appalachians are run-in low mountains.

The giant ocean that washed Pangea is called

Panthalassa .

About 200 million years ago, Pangea began to split and first broke up into two continents: Laurasia and Gondwana.

Further splits divided Laurasia into North America and Eurasia, and Gondwana - to the southern continents: Africa, South America, India, Australia and Antarctica.

Due to the divergence of the lithospheric plates, the continents moved away from each other and eventually occupied their present position. Between the continents, the depressions of the Atlantic, Indian and Arctic oceans expanded.

What awaits the continents in the future?

The black lines on the maps are the boundaries of giant plates, slowly and steadily spreading the continents. Now scientists can predict the geography of the future: the latest map tells about the planet tomorrow. Look - the Atlantic Ocean has become even wider, and Africa has split.

Presumably, our continents will collide again and form a new supercontinent, which has already been given a name - Pangea Ultima. The term Pangea Ultima and the very theory of the appearance of the mainland were coined by the American geologist Christopher Scotese, who, using various methods calculation of the movement of lithospheric plates, found that the merger could occur somewhere in 200 million years.

The last Pangea, as this continent is sometimes called in Russia, will be almost entirely covered with deserts, and in the northwest and southeast there will be huge mountain ranges.