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Lithospheric map of the world. "Lithospheric plates

According to modern plate theory The entire lithosphere is divided into separate blocks by narrow and active zones - deep faults - moving in the plastic layer of the upper mantle relative to each other at a speed of 2-3 cm per year. These blocks are called lithospheric plates.

The peculiarity of lithospheric plates is their rigidity and ability in the absence of external influences long time maintain unchanged shape and structure.

Lithospheric plates are mobile. Their movement along the surface of the asthenosphere occurs under the influence of convective currents in the mantle. Individual lithospheric plates can move apart, move closer together, or slide relative to each other. In the first case, tension zones with cracks along the boundaries of the plates appear between the plates, in the second - compression zones, accompanied by the pushing of one plate onto another (thrusting - obduction; thrusting - subduction), in the third - shear zones - faults along which sliding of neighboring plates occurs .

Where continental plates converge, they collide and mountain belts are formed. This is how, for example, the Himalaya mountain system arose on the border of the Eurasian and Indo-Australian plates (Fig. 1).

Rice. 1. Collision of continental lithospheric plates

When the continental and oceanic plates interact, the plate with the oceanic crust moves under the plate with the continental crust (Fig. 2).

Rice. 2. Collision of continental and oceanic lithospheric plates

As a result of the collision of continental and oceanic lithospheric plates, deep-sea trenches and island arcs are formed.

The divergence of lithospheric plates and the resulting formation of the oceanic crust is shown in Fig. 3.

The axial zones of mid-ocean ridges are characterized by rifts(from English rift - crevice, crack, fault) - a large linear tectonic structure of the earth's crust hundreds, thousands in length, tens and sometimes hundreds of kilometers wide, formed mainly during horizontal stretching of the crust (Fig. 4). Very large rifts are called rift belts, zones or systems.

Since the lithospheric plate is a single plate, each of its faults is a source of seismic activity and volcanism. These sources are concentrated within relatively narrow zones along which mutual movements and friction of adjacent plates occur. These zones are called seismic belts. Reefs, mid-ocean ridges and deep-sea trenches are mobile regions of the Earth and are located at the boundaries of lithospheric plates. This indicates that the process of formation of the earth's crust in these zones is currently occurring very intensively.

Rice. 3. Divergence of lithospheric plates in the zone among the oceanic ridge

Rice. 4. Rift formation scheme

Most of the faults of lithospheric plates occur at the bottom of the oceans, where the earth’s crust is thinner, but they also occur on land. The largest fault on land is located in eastern Africa. It stretches for 4000 km. The width of this fault is 80-120 km.

Currently, seven of the largest plates can be distinguished (Fig. 5). Of these, the largest in area is the Pacific, which consists entirely of oceanic lithosphere. As a rule, the Nazca plate, which is several times smaller in size than each of the seven largest ones, is also classified as large. At the same time, scientists suggest that in fact the Nazca plate is much larger than we see on the map (see Fig. 5), since a significant part of it went under neighboring plates. This plate also consists only of oceanic lithosphere.

Rice. 5. Earth's lithospheric plates

An example of a plate that includes both continental and oceanic lithosphere is, for example, the Indo-Australian lithospheric plate. The Arabian plate consists almost entirely of continental lithosphere.

The theory of lithospheric plates is important. First of all, it can explain why there are mountains in some places on Earth and plains in others. Using the theory of lithospheric plates, it is possible to explain and predict catastrophic phenomena occurring at plate boundaries.

Rice. 6. The shapes of the continents really seem compatible.

Continental drift theory

The theory of lithospheric plates originates from the theory of continental drift. Back in the 19th century. many geographers have noted that when looking at a map, one can notice that the coasts of Africa and South America seem compatible when approaching (Fig. 6).

The emergence of the hypothesis of continental movement is associated with the name of the German scientist Alfred Wegener(1880-1930) (Fig. 7), who most fully developed this idea.

Wegener wrote: “In 1910, the idea of moving continents first occurred to me... when I was struck by the similarity of the outlines of the coasts on both sides of the Atlantic Ocean.” He suggested that in the early Paleozoic there were two large continents on Earth - Laurasia and Gondwana.

Laurasia was the northern continent, which included the territories of modern Europe, Asia without India and North America. The southern continent - Gondwana united the modern territories of South America, Africa, Antarctica, Australia and Hindustan.

Between Gondwana and Laurasia there was the first sea - Tethys, like a huge bay. The rest of the Earth's space was occupied by the Panthalassa Ocean.

About 200 million years ago, Gondwana and Laurasia were united into a single continent - Pangea (Pan - universal, Ge - earth) (Fig. 8).

Rice. 8. The existence of a single continent of Pangea (white - land, dots - shallow sea)

About 180 million years ago, the continent of Pangea again began to separate into its component parts, which mixed on the surface of our planet. The division occurred as follows: first Laurasia and Gondwana reappeared, then Laurasia split, and then Gondwana split. Due to the split and divergence of parts of Pangea, oceans were formed. The Atlantic and Indian oceans can be considered young oceans; old - Quiet. The Arctic Ocean became isolated as landmass increased in the Northern Hemisphere.

Rice. 9. Location and directions of continental drift during the Cretaceous period 180 million years ago

A. Wegener found many confirmations of the existence of a single continent of the Earth. He found the existence of remains of ancient animals—listosaurs—in Africa and South America especially convincing. These were reptiles, similar to small hippopotamuses, that lived only in freshwater bodies of water. This means swimming huge distances on the salty sea water they couldn't. He found similar evidence in the plant world.

Interest in the hypothesis of continental movement in the 30s of the 20th century. decreased somewhat, but was revived again in the 60s, when, as a result of studies of the relief and geology of the ocean floor, data were obtained indicating the processes of expansion (spreading) of the oceanic crust and the “diving” of some parts of the crust under others (subduction).

Hello dear reader. Never before did I think that I would have to write these lines. For quite a long time I did not dare to write down everything that I was destined to discover, if you can even call it that. I still sometimes wonder if I’ve gone crazy.

One evening my daughter came up to me with a request to show me on a map where and what ocean is located on our planet, and since I don’t have a printed physical map of the world at home, I opened an electronic map on the computerGoogle,I switched her to satellite view mode and began to slowly explain everything to her. When I reached the Atlantic Ocean from the Pacific Ocean and brought it closer to show my daughter better, it was like an electric shock struck me and I suddenly saw what every person on our planet sees, but with completely different eyes. Like everyone else, until that moment I didn’t understand that I was seeing the same thing on the map, but then it was as if my eyes were opened. But all these are emotions, and you can’t cook cabbage soup out of emotions. So let's try together to see what the map revealed to meGoogle,and what was discovered was nothing less than a trace of the collision of our Mother Earth with an unknown celestial body, which led to what is commonly called the Great Later.

Look carefully at the lower left corner of the photo and think: does this remind you of anything? I don’t know about you, but it reminds me of a clear trace of the impact of some rounded celestial body on the surface of our planet. Moreover, the impact was in front of the mainland of South America and Antarctica, which from the impact are now slightly concave in the direction of the impact and are separated in this place by a strait named after the Drake Strait, the pirate who allegedly discovered this strait in the past.

In fact, this strait is a pothole left at the moment of impact and ending in a rounded “contact spot” of the celestial body with the surface of our planet. Let's take a closer look at this “contact patch”.

Looking closer, we see a rounded spot that has a concave surface and ends on the right, that is, on the side in the direction of impact, with a characteristic hill with an almost vertical edge, which again has characteristic elevations that emerge on the surface of the world ocean in the form of islands. In order to better understand the nature of the formation of this “contact spot,” you can do the same experiment that I did. The experiment requires a wet sandy surface. A sandy surface on the banks of a river or sea is perfect. During the experiment, you need to make a smooth movement with your hand, during which you move your hand over the sand, then touch the sand with your finger and, without stopping the movement of your hand, apply pressure to it, thereby raking up a certain amount of sand with your finger and then after a while, tear off your finger from the surface of the sand. Did you do it? Now look at the result of this simple experiment and you will see a picture completely similar to the one shown in the photo below.

There is one more funny nuance. According to researchers, the north pole of our planet has shifted by about two thousand kilometers in the past. If we measure the length of the so-called pothole on the ocean floor in the Drake Passage and ending with the “contact patch,” then it also approximately corresponds to two thousand kilometers. In the photo I took measurements using the programGoogle Maps.Moreover, researchers cannot answer the question of what caused the pole shift. I don’t presume to say with 100% probability, but it’s still worth thinking about the question: was it not this catastrophe that caused the shift of the poles of planet Earth by these same two thousand kilometers?

Now let's ask ourselves: what happened after the celestial body hit the planet tangentially and again went into space? You may ask: why on a tangent and why did it necessarily go away, and not break through the surface and plunge into the bowels of the planet? Everything here is also very simply explained. Do not forget about the direction of rotation of our planet. It was precisely the coincidence of circumstances that the celestial body presented during the rotation of our planet that saved it from destruction and allowed the celestial body, so to speak, to slip and go away, and not bury itself in the bowels of the planet. It was no less fortunate that the impact fell on the ocean in front of the continent, and not on the continent itself, since the waters of the ocean somewhat dampened the impact and played the role of a kind of lubricant when the celestial bodies touched, but this fact also had reverse side medals - the ocean waters also played their destructive role after the body was torn off and went into space.

Now let's see what happened next. I think there is no need to prove to anyone that the consequence of the impact that led to the formation of the Drake Passage was the formation of a huge multi-kilometer wave, which rushed forward at great speed, sweeping away everything in its path. Let's follow the path of this wave.

The wave crossed the Atlantic Ocean and the first obstacle in its path was the southern tip of Africa, although it suffered relatively little damage, as the wave touched it with its edge and turned slightly to the south, where it hit Australia. But Australia was much less fortunate. It took the blow of the wave and was practically washed away, which is very clearly visible on the map.

Then the wave crossed the Pacific Ocean and passed between the Americas, again touching North America with its edge. We see the consequences of this both on the map and in the films of Sklyarov, who very picturesquely described the consequences of the Great Flood in North America. If anyone hasn’t watched it or has already forgotten, they can re-watch these films, since they have long been posted for free access on the Internet. These are very educational films, although not everything in them should be taken seriously.

Then the wave crossed the Atlantic Ocean for the second time and with its entire mass at full speed hit the northern tip of Africa, sweeping away and washing away everything in its path. This is also clearly visible on the map. From my point of view, we owe such a strange arrangement of deserts on the surface of our planet not to the quirks of climate or reckless human activity, but to the destructive and merciless impact of the wave during the Great Flood, which not only swept away everything in its path, but also literally this word washed away everything, including not only buildings and vegetation, but also the fertile layer of soil on the surface of the continents of our planet.

After Africa, the wave swept across Asia and again crossed the Pacific Ocean and, passing through the gap between our continent and North America, went to the North Pole through Greenland. Having reached the north pole of our planet, the wave extinguished itself, because it exhausted its power, successively slowing down on the continents on which it flew, and by the fact that at the north pole it eventually caught up with itself.

After this, the water of the already extinct wave began to roll back from the North Pole to the south. Some of the water passed through our continent. This is precisely what can explain the still flooded northern tip of our continent and the abandoned Gulf of Finland and the cities of Western Europe, including our Petrograd and Moscow, buried under a multi-meter layer of earth that was brought from the North Pole.

Map of tectonic plates and faults in the Earth's crust

If there was an impact from a celestial body, then it is quite reasonable to look for its consequences in the thickness of the Earth’s crust. After all, a blow of such force simply could not leave any traces. Let's look at the map of tectonic plates and faults in the Earth's crust.

What do we see there on this map? The map clearly shows a tectonic fault at the site of not only the trace left by the celestial body, but also around the so-called “contact spot” at the site of the separation of the celestial body from the surface of the Earth. And these faults once again confirm the correctness of my conclusions about the impact of a certain celestial body. And the blow was so strong that it not only demolished the isthmus between South America and Antarctica, but also led to the formation of a tectonic fault in the Earth’s crust in this place.

Oddities of the trajectory of a wave on the surface of the planet

I think it’s worth talking about one more aspect of the wave’s movement, namely its non-linearity and unexpected deviations in one direction or the other. Since childhood, we have all been taught to believe that we live on a planet that has the shape of a ball, which is slightly flattened at the poles.

I myself held the same opinion for quite a long time. And imagine my surprise when in 2012 I came across the results of a study by the European Space Agency ESA using data obtained by the GOCE (Gravity field and steady-state Ocean Circulation Explorer) satellite for research gravitational field and constant ocean currents).

Below I present some photographs of the actual shape of our planet. Moreover, it is worth taking into account the fact that this is the shape of the planet itself without taking into account the waters on its surface that form the world ocean. You may ask a completely legitimate question: what do these photographs have to do with the topic being discussed here? From my point of view, this is the most direct thing. After all, not only does the wave move along the surface of a celestial body that has an irregular shape, but its movement is affected by impacts from the wave front.

No matter how cyclopean the size of the wave, these factors cannot be discounted, because what we consider a straight line on the surface of a globe shaped like a regular ball turns out to be far from a rectilinear trajectory, and vice versa - what in reality is a rectilinear trajectory on the irregularly shaped surfaces on the globe will turn into an intricate curve.

And we have not yet considered the fact that when moving along the surface of the planet, the wave repeatedly encountered various obstacles in the form of continents on its path. And if we return to the expected trajectory of the wave along the surface of our planet, we can see that for the first time it touched both Africa and Australia with its peripheral part, and not with its entire front. This could not but affect not only the trajectory of movement itself, but also the growth of the wave front, which, each time it met an obstacle, was partially broken off and the wave had to start growing again. And if we consider the moment of its passage between the two Americas, then it is impossible not to notice the fact that at the same time the wave front was not only truncated once again, but also part of the wave, due to re-reflection, turned south and washed away the coast of South America.

Approximate time of the disaster

Now let's try to find out when this disaster occurred. To do this, it would be possible to send an expedition to the site of the disaster, examine it in detail, take all kinds of soil and rock samples and try to study them in laboratories, then follow the route of the Great Flood and do the same work again. But all this would cost a lot of money, would take a long time, for many years and it is not at all necessary that my whole life would be enough to carry out these works.

But is all this really necessary and is it possible to do without such expensive and resource-intensive measures, at least for now, at first? I believe that at this stage, to establish the approximate time of the catastrophe, you and I will be able to make do with information obtained earlier and now in open sources, as we have already done when considering the planetary catastrophe that led to the Great Flood.

To do this, we should turn to physical maps of the world from different centuries and establish when the Drake Passage appeared on them. After all, we previously established that it was the Drake Passage that was formed as a result and at the site of this planetary catastrophe.

Below are the physical maps that I was able to find in open access and the authenticity of which does not cause much distrust.

Here is a map of the World dating back to 1570 AD

As we can see, there is no Drake Passage on this map and South America is still connected to Antarctica. This means that in the sixteenth century there was no catastrophe yet.

Let's take a map from the early seventeenth century and see if the Drake Passage and the peculiar outlines of South America and Antarctica appeared on the map in the seventeenth century. After all, sailors could not fail to notice such a change in the landscape of the planet.

Here is a map dating from the early seventeenth century. Unfortunately, I do not have a more accurate dating, as was the case with the first map. On the resource where I found this map, the date was exactly this: “early seventeenth century.” But in this case this is not of a fundamental nature.

The fact is that on this map both South America and Antarctica and the bridge between them are in their place, and therefore either the disaster had not yet happened, or the cartographer did not know about what happened, although it’s hard to believe in this, knowing the scale of the disaster and everything the consequences to which it led.

Here's another card. This time the dating of the map is more accurate. It also dates from the seventeenth century - this is 1630 from the Nativity of Christ.

And what do we see on this map? Although the outlines of the continents are drawn on it not as well as in the previous one, it is clearly visible that the strait in its modern form is not on the map.

Well, apparently in this case the picture described when considering the previous map is repeated. We continue to move along the timeline towards our days and once again take a map more recent than the previous one.

This time I did not find a physical map of the world. I found a map of North and South America; in addition, it does not show Antarctica at all. But this is not so important. After all, we remember the outlines of the southern tip of South America from previous maps, and we can notice any changes in them even without Antarctica. But this time the dating of the map is in complete order - it is dated to the very end of the seventeenth century, namely 1686 from the Nativity of Christ.

Let's take a look at South America and compare its outlines with what we saw on the previous map.

On this map we finally see not the already tired antediluvian outlines of South America and the isthmus connecting South America with Antarctica in the place of the modern and familiar Drake Passage, but the most familiar modern South America with a curved towards the “contact patch” southern end.

What conclusions can be drawn from all of the above? There are two fairly simple and obvious conclusions:

Which of these conclusions is correct and which is false, to my great regret, I cannot judge, because the available information is clearly not enough for this yet.

Confirmation of disaster

Where can you find confirmation of the fact of the disaster, except for the physical maps that we talked about above. I’m afraid to seem unoriginal, but the answer will be quite simple: firstly, under your feet and secondly, in works of art, namely in the paintings of artists. I doubt that any of the eyewitnesses would have been able to capture the wave itself, but the consequences of this tragedy were fully captured. There were quite a large number of artists who painted paintings that reflected the picture of terrible devastation that reigned in the seventeenth and eighteenth centuries in the place of Egypt, modern Western Europe and Mother Rus'. But they prudently told us that these artists did not paint from life, but depicted on their canvases the so-called world they imagined. I will cite the works of just a few fairly prominent representatives of this genre:

This is what the now familiar antiquities of Egypt looked like before they were literally dug up from under a thick layer of sand.

What happened in Europe at that time? Giovanni Battista Piranesi, Hubert Robert and Charles-Louis Clerisseau will help us understand.

But these are not all the facts that can be cited in support of the disaster and which I have yet to systematize and describe. There are also cities in Mother Rus' covered with earth for several meters, there is the Gulf of Finland, which is also covered with earth and became truly navigable only at the end of the nineteenth century, when the world's first sea canal was dug along its bottom. There are salty sands of the Moscow River, sea shells and devil's fingers, which I dug up as a boy in the forest sands in the Bryansk region. And Bryansk itself, which according to the official historical legend got its name from the wilds where it supposedly stands, really doesn’t smell like wilds in the Bryansk region, but this is a subject for a separate conversation and God willing, in the future I will publish my thoughts on this topic. There are deposits of bones and carcasses of mammoths, the meat of which was fed to dogs in Siberia at the end of the twentieth century. I will consider all this in more detail in the next part of this article.

In the meantime, I appeal to all readers who spent their time and effort and read the article to the end. Do not remain open-hearted - express any critical comments, point out inaccuracies and errors in my reasoning. Ask any questions - I will definitely answer them!

How did continents and islands appear? What determines the name of the largest plates of the Earth? Where did our planet come from?

How did it all start?

Everyone has thought at least once about the origin of our planet. For deeply religious people, everything is simple: God created the Earth in 7 days, period. They are unshakable in their confidence, even knowing the names of the largest ones formed as a result of the evolution of the surface of the planet. For them, the birth of our stronghold is a miracle, and no arguments of geophysicists, naturalists and astronomers can convince them.

Scientists, however, have a different opinion, based on hypotheses and assumptions. They make guesses, put forward versions and come up with a name for everything. This also affected the largest plates of the Earth.

At the moment, it is not known for certain how our firmament appeared, but there are many interesting opinions. It was the scientists who unanimously decided that there once existed a single gigantic continent, which, as a result of cataclysms and natural processes, split into parts. Scientists also came up with not only the names of the largest plates of the Earth, but also designated the small ones.

A theory bordering on science fiction

For example, Pierre Laplace, scientists from Germany, believed that the Universe emerged from a gas nebula, and the Earth is a gradually cooling planet, the crust of which is nothing more than a cooled surface.

Another scientist believed that the Sun, when passing through a gas and dust cloud, captured part of it with itself. His version is that our Earth was never a completely molten substance and was originally a cold planet.

According to the theory of the English scientist Fred Hoyle, the Sun had its own twin star, which exploded like a supernova. Almost all the fragments were thrown over vast distances, and the small number remaining around the Sun turned into planets. One of these fragments became the cradle of humanity.

Version as an axiom

The most common story of the origin of the Earth is as follows:

About 7 billion years ago, the primary cold planet formed, after which its interior began to gradually warm up.
Then, during the so-called “lunar era,” red-hot lava poured out onto the surface in gigantic quantities. This entailed the formation of the primary atmosphere and served as an impetus for the formation of the earth's crust - the lithosphere.
Thanks to the primary atmosphere, oceans appeared on the planet, as a result of which the Earth was covered with a dense shell, representing the outlines of oceanic depressions and continental protrusions. In those distant times, the area of water significantly prevailed over the area of land. By the way, and upper part The mantle is called the lithosphere, which forms the lithospheric plates that make up the overall “look” of the Earth. The names of the largest plates correspond to their geographical location.

Giant rift

How did continents and lithospheric plates form? About 250 million years ago, the Earth looked completely different from what it does now. Then on our planet there was only one, simply gigantic continent called Pangea. Its total area was impressive and equal to the area of all existing continents, including islands. Pangea was washed on all sides by an ocean called Panthalassa. This huge ocean occupied the entire remaining surface of the planet.

However, the existence of the supercontinent turned out to be short-lived. Processes were seething inside the Earth, as a result of which the substance of the mantle began to spread in different directions, gradually stretching the continent. Because of this, Pangea first split into two parts, forming two continents - Laurasia and Gondwana. Then these continents gradually split into many parts, which gradually dispersed in different directions. In addition to new continents, lithospheric plates appeared. From the names of the largest plates, it becomes clear in which places giant faults formed.

The remains of Gondwana are the Australia and Antarctica we know, as well as the South African and African lithospheric plates. It has been proven that these plates are gradually moving apart in our time - the speed of movement is 2 cm per year.

The fragments of Laurasia turned into two lithospheric plates - North American and Eurasian. Moreover, Eurasia consists not only of a fragment of Laurasia, but also of parts of Gondwana. The names of the largest plates that form Eurasia are Hindustan, Arabian and Eurasian.

Africa takes a direct part in the formation of the Eurasian continent. Its lithospheric plate is slowly moving closer to the Eurasian plate, forming mountains and hills. It was because of this “union” that the Carpathians, Pyrenees, Alps and Sudetes appeared.

List of lithospheric plates

The names of the largest plates are:

South American;
Australian;
Eurasian;
North American;
Antarctic;
Pacific;
South American;
Hindustan.

Medium sized slabs are:

Arabian;
Nazca;
Scotia;
Philippine;
Coconut;
Juan de Fuca.

The lithosphere is the rocky shell of the Earth. From the Greek “lithos” - stone and “sphere” - ball

The lithosphere is the outer solid shell of the Earth, which includes the entire Earth's crust with part of the Earth's upper mantle and consists of sedimentary, igneous and metamorphic rocks. The lower boundary of the lithosphere is unclear and is determined by a sharp decrease in the viscosity of rocks, a change in the speed of propagation of seismic waves and an increase in the electrical conductivity of rocks. The thickness of the lithosphere on continents and under the oceans varies and averages 25 - 200 and 5 - 100 km, respectively.

Let's consider in general view geological structure of the Earth. The third planet beyond the distance from the Sun, Earth, has a radius of 6370 km, an average density of 5.5 g/cm3 and consists of three shells - bark, mantle and and. The mantle and core are divided into internal and external parts.

The Earth's crust is the thin upper shell of the Earth, which is 40-80 km thick on the continents, 5-10 km under the oceans and makes up only about 1% of the Earth's mass. Eight elements - oxygen, silicon, hydrogen, aluminum, iron, magnesium, calcium, sodium - form 99.5% of the earth's crust.

According to scientific research, scientists were able to establish that the lithosphere consists of:

Oxygen – 49%;
Silicon – 26%;
Aluminum – 7%;
Iron – 5%;
Calcium – 4%
The lithosphere contains many minerals, the most common being spar and quartz.

On continents, the crust is three-layered: sedimentary rocks cover granite rocks, and granite rocks overlie basaltic rocks. Under the oceans the crust is “oceanic”, of a two-layer type; sedimentary rocks simply lie on basalts, there is no granite layer. There is also a transitional type of the earth's crust (island-arc zones on the margins of the oceans and some areas on continents, for example the Black Sea).

The earth's crust is thickest in mountainous regions(under the Himalayas - over 75 km), the average - in the areas of the platforms (under the West Siberian Lowland - 35-40, within the borders of the Russian Platform - 30-35), and the smallest - in the central regions of the oceans (5-7 km). The predominant part earth's surface- These are the plains of continents and the ocean floor.

The continents are surrounded by a shelf - a shallow strip with a depth of up to 200 g and an average width of about 80 km, which, after a sharp steep bend of the bottom, turns into a continental slope (the slope varies from 15-17 to 20-30°). The slopes gradually level out and turn into abyssal plains (depths 3.7-6.0 km). The oceanic trenches have the greatest depths (9-11 km), the vast majority of which are located on the northern and western edges of the Pacific Ocean.

The main part of the lithosphere consists of igneous igneous rocks (95%), among which granites and granitoids predominate on the continents, and basalts in the oceans.

Blocks of the lithosphere - lithospheric plates - move along a relatively plastic asthenosphere. The section of geology on plate tectonics is devoted to the study and description of these movements.

To designate the outer shell of the lithosphere, the now obsolete term sial was used, derived from the name of the main rock elements Si (Latin: Silicium - silicon) and Al (Latin: Aluminum - aluminum).

Lithospheric plates

It is worth noting that the largest tectonic plates are very clearly visible on the map and they are:

Pacific- the largest plate on the planet, along the boundaries of which constant collisions of tectonic plates occur and faults form - this is the reason for its constant decrease;
Eurasian– covers almost the entire territory of Eurasia (except for Hindustan and the Arabian Peninsula) and contains the largest part of the continental crust;
Indo-Australian– it includes the Australian continent and the Indian subcontinent. Due to constant collisions with the Eurasian plate, it is in the process of breaking;
South American– consists of the South American continent and part of the Atlantic Ocean;
North American– consists of the North American continent, part of northeastern Siberia, the northwestern part of the Atlantic and half of the Arctic oceans;
African– consists of the African continent and the oceanic crust of the Atlantic and Indian oceans. Interestingly, the plates adjacent to it move in the opposite direction from it, so the largest fault on our planet is located here;
Antarctic plate– consists of the continent of Antarctica and the nearby oceanic crust. Due to the fact that the plate is surrounded by mid-ocean ridges, the remaining continents are constantly moving away from it.

Movement of tectonic plates in the lithosphere

Lithospheric plates, connecting and separating, constantly change their outlines. This allows scientists to put forward the theory that about 200 million years ago the lithosphere had only Pangea - a single continent, which subsequently split into parts, which began to gradually move away from each other at a very low speed (on average about seven centimeters per year ).

This is interesting! There is an assumption that, thanks to the movement of the lithosphere, in 250 million years a new continent will form on our planet due to the unification of moving continents.

When the oceanic and continental plates collide, the edge of the oceanic crust is subducted under the continental crust, while on the other side of the oceanic plate its boundary diverges from the adjacent plate. The boundary along which the movement of lithospheres occurs is called the subduction zone, where the upper and subducting edges of the plate are distinguished. It is interesting that the plate, plunging into the mantle, begins to melt when the upper part of the earth’s crust is compressed, as a result of which mountains are formed, and if magma also erupts, then volcanoes.

In places where tectonic plates come into contact with each other, zones of maximum volcanic and seismic activity are located: during the movement and collision of the lithosphere, the earth's crust is destroyed, and when they diverge, faults and depressions are formed (the lithosphere and the Earth's topography are connected to each other). This is the reason that the Earth's largest landforms—mountain ranges with active volcanoes and deep-sea trenches—are located along the edges of tectonic plates.

Lithosphere problems

The intensive development of industry has led to the fact that man and the lithosphere have recently begun to get along extremely poorly with each other: the pollution of the lithosphere is acquiring catastrophic proportions. This happened due to the increase in industrial waste in combination with household waste and fertilizers and pesticides used in agriculture, which negatively affects the chemical composition of the soil and living organisms. Scientists have calculated that about one ton of garbage is generated per person per year, including 50 kg of hard-to-degrade waste.

Today, pollution of the lithosphere has become an urgent problem, since nature is not able to cope with it on its own: the self-cleaning of the earth’s crust occurs very slowly, and therefore harmful substances gradually accumulate and, over time, negatively affect the main culprit of the problem - humans.

Consists of many layers piled on top of each other. However, what we know best is the earth's crust and lithosphere. This is not surprising - after all, we not only live on them, but also draw from the depths most of the natural resources available to us. But the upper shells of the Earth still preserve millions of years of history of our planet and the entire solar system.

These two concepts appear so often in the press and literature that they have entered the everyday vocabulary modern man. Both words are used to refer to the surface of the Earth or another planet - however, there is a difference between the concepts, based on two fundamental approaches: chemical and mechanical.

Chemical aspect - earth's crust

If we divide the Earth into layers, guided by differences in chemical composition, the top layer of the planet will be the earth's crust. This is a relatively thin shell, ending at a depth of 5 to 130 kilometers below sea level - the oceanic crust is thinner, and the continental crust, in mountainous areas, is thickest. Although 75% of the crust's mass is composed only of silicon and oxygen (not pure, bound in different substances), it has the greatest chemical diversity of all layers of the Earth.

The wealth of minerals also plays a role - various substances and mixtures created over billions of years of the planet’s history. The Earth's crust contains not only "native" minerals that were created by geological processes, but also massive organic heritage, such as oil and coal, as well as alien inclusions.

Physical aspect - lithosphere

Based on the physical characteristics of the Earth, such as hardness or elasticity, we will get a slightly different picture - the interior of the planet will be covered by the lithosphere (from the other Greek lithos, “rocky, hard” and “sphaira” sphere). It is much thicker than the earth's crust: the lithosphere extends up to 280 kilometers deep and even covers the upper solid part of the mantle!

The characteristics of this shell fully correspond to the name - it is the only solid layer of the Earth, besides the inner core. Strength, however, is relative - the Earth’s lithosphere is one of the most mobile in the solar system, which is why the planet has changed its structure more than once appearance. But significant compression, curvature and other elastic changes require thousands of years, if not more.

An interesting fact is that the planet may not have a surface crust. So, the surface is its hardened mantle; The planet closest to the Sun lost its crust a long time ago as a result of numerous collisions.

To summarize, the Earth's crust is the upper, chemically diverse part of the lithosphere, the hard shell of the Earth. Initially they had almost the same composition. But when the depths were affected only by the underlying asthenosphere and high temperatures, the hydrosphere, atmosphere, meteorite remains and living organisms actively participated in the formation of minerals on the surface.

Lithospheric plates

Another feature that distinguishes the Earth from other planets is the diversity of different types of landscapes on it. Of course, water also played an incredibly important role, which we will talk about a little later. But even the basic forms of the planetary landscape of our planet differ from the same Moon. The seas and mountains of our satellite are pits from bombardment by meteorites. And on Earth they were formed as a result of hundreds and thousands of millions of years of movement of lithospheric plates.

You've probably already heard about plates - these are huge stable fragments of the lithosphere that drift along the fluid asthenosphere, like broken ice on a river. However, there are two main differences between the lithosphere and ice:

The gaps between the plates are small and are quickly closed due to the molten substance erupting from them, and the plates themselves are not destroyed by collisions.
Unlike water, there is no constant flow in the mantle, which could set a constant direction for the movement of the continents.

Thus, the driving force behind the drift of lithospheric plates is the convection of the asthenosphere, the main part of the mantle - hotter flows from the earth's core rise to the surface when cold ones fall back down. Considering that the continents differ in size, and the topography of their lower side mirrors the irregularities of the upper side, they also move unevenly and inconsistently.

Main plates

Over billions of years of movement of lithospheric plates, they repeatedly merged into supercontinents, after which they separated again. In the near future, in 200–300 million years, the formation of a supercontinent called Pangea Ultima is also expected. We recommend watching the video at the end of the article - it clearly shows how lithospheric plates have migrated over the past several hundred million years. In addition, the strength and activity of continental movement is determined by the internal heating of the Earth - the higher it is, the more the planet expands, and the faster and freer the lithospheric plates move. However, since the beginning of the Earth's history, its temperature and radius have been gradually decreasing.

An interesting fact is that plate drift and geological activity do not necessarily have to be powered by the internal self-heating of the planet. For example, the satellite of Jupiter has many active volcanoes. But the energy for this is not provided by the satellite’s core, but by gravitational friction c, due to which Io’s interior heats up.

The boundaries of lithospheric plates are very arbitrary - some parts of the lithosphere sink under others, and some, like the Pacific plate, are completely hidden under water. Geologists today count 8 main plates that cover 90 percent of the entire Earth's area:

Australian
Antarctic
African
Eurasian
Hindustan
Pacific
North American
South American

Such a division appeared recently - for example, the Eurasian plate, 350 million years ago, consisted of separate parts, during the merger of which the Ural Mountains, one of the oldest on Earth, were formed. Scientists to this day continue to study faults and the ocean floor, discovering new plates and clarifying the boundaries of old ones.

Geological activity

Lithospheric plates move very slowly - they creep over each other at a speed of 1–6 cm/year, and move away at a maximum of 10–18 cm/year. But it is the interaction between the continents that creates the geological activity of the Earth, noticeable on the surface - volcanic eruptions, earthquakes and the formation of mountains always occur in the contact zones of lithospheric plates.

However, there are exceptions - so-called hot spots, which can also exist deep in lithospheric plates. In them, molten flows of asthenosphere matter break upward, melting the lithosphere, which leads to increased volcanic activity and regular earthquakes. Most often, this happens near those places where one lithospheric plate creeps onto another - the lower, depressed part of the plate sinks into the Earth's mantle, thereby increasing the pressure of magma on the upper plate. However, now scientists are inclined to believe that the “drowned” parts of the lithosphere are melting, increasing pressure in the depths of the mantle and thereby creating upward flows. This can explain the anomalous distance of some hot spots from tectonic faults.

An interesting fact is that shield volcanoes, characterized by their flat shape, often form in hot spots. They erupt many times, growing due to flowing lava. This is also a typical alien volcano format. The most famous of them is on Mars, the highest point on the planet - its height reaches 27 kilometers!

Oceanic and continental crust of the Earth

The interaction of plates also leads to the formation of two various types earth's crust - oceanic and continental. Since the oceans, as a rule, are the junctions of different lithospheric plates, their crust is constantly changing - being broken or absorbed by other plates. At the site of faults, direct contact occurs with the mantle, from where hot magma rises. As it cools under the influence of water, it creates a thin layer of basalts, the main volcanic rock. Thus, the oceanic crust is completely renewed every 100 million years - the oldest areas, which are located in the Pacific Ocean, reach a maximum age of 156–160 million years.

Important! The oceanic crust is not all of the earth’s crust that is under water, but only its young sections at the junction of continents. Part of the continental crust is under water, in the zone of stable lithospheric plates.