The earth's crust has great value for our life, for research of our planet.

This concept is closely related to others that characterize processes occurring inside and on the surface of the Earth.

What is the earth's crust and where is it located?

The Earth has a holistic and continuous shell, which includes: the earth's crust, the troposphere and stratosphere, which are the lower part of the atmosphere, the hydrosphere, the biosphere and the anthroposphere.

They interact closely, penetrating each other and constantly exchanging energy and matter. The earth's crust is usually called the outer part of the lithosphere - the solid shell of the planet. Most of it outside covered by the hydrosphere. The remaining, smaller part is affected by the atmosphere.

Beneath the Earth's crust is a denser and more refractory mantle. They are separated by a conventional border named after the Croatian scientist Mohorovic. Its peculiarity is a sharp increase in the speed of seismic vibrations.

Various scientific methods are used to gain insight into the earth's crust. However, obtaining specific information is only possible by drilling to great depths.

One of the objectives of such research was to establish the nature of the boundary between the upper and lower continental crust. The possibilities of penetrating the upper mantle using self-heating capsules made of refractory metals were discussed.

Structure of the earth's crust

Beneath the continents are its sedimentary, granite and basalt layers, the total thickness of which is up to 80 km. Rocks, called sedimentary rocks, are formed by the deposition of substances on land and in water. They are located mainly in layers.

clay
shale
sandstones
carbonate rocks
rocks of volcanic origin
coal and other breeds.

The sedimentary layer helps to learn more deeply about natural conditions on earth that were on the planet in time immemorial. This layer can have different thicknesses. In some places it may not exist at all, in other, mainly large depressions, it can be 20-25 km.

Temperature of the earth's crust

An important energy source for the inhabitants of the Earth is the heat of its crust. The temperature increases as you go deeper into it. The 30-meter layer closest to the surface, called the heliometric layer, is associated with the heat of the sun and fluctuates depending on the season.

In the next, thinner layer, which increases in a continental climate, the temperature is constant and corresponds to the indicators of a specific measurement location. In the geothermal layer of the crust, the temperature is related to the internal heat of the planet and increases as you go deeper into it. She in different places different and depends on the composition of the elements, depth and conditions of their location.

It is believed that the temperature increases on average by three degrees as you go deeper for every 100 meters. Unlike the continental part, temperatures under the oceans are rising faster. After the lithosphere there is a plastic high-temperature shell, the temperature of which is 1200 degrees. It is called the asthenosphere. There are places with molten magma in it.

Penetrating into the earth's crust, the asthenosphere can pour out molten magma, causing volcanic phenomena.

Characteristics of the Earth's crust

The Earth's crust has a mass of less than half a percent of the total mass of the planet. It is the outer shell of the stone layer in which the movement of matter occurs. This layer, which has a density half that of the Earth. Its thickness varies between 50-200 km.

Uniqueness earth's crust is that it can be of continental and oceanic types. The continental crust has three layers, the top of which is formed by sedimentary rocks. The oceanic crust is relatively young and its thickness varies slightly. It is formed due to mantle substances from oceanic ridges.

earth's crust characteristics photo

The thickness of the crust layer under the oceans is 5-10 km. Its peculiarity is constant horizontal and oscillatory movements. Most of the crust is basalt.

The outer part of the earth's crust is the solid shell of the planet. Its structure is distinguished by the presence of movable areas and relatively stable platforms. Lithospheric plates move relative to each other. The movement of these plates can cause earthquakes and other disasters. The patterns of such movements are studied by tectonic science.

Functions of the earth's crust

The main functions of the earth's crust are:

resource;
geophysical;
geochemical.

The first of them indicates the presence of the Earth's resource potential. It is primarily a collection of mineral reserves located in the lithosphere. In addition, the resource function includes a number of environmental factors that provide life for humans and others. biological objects. One of them is the tendency of a hard surface deficit to form.

You can't do that. let's save our Earth photo

Thermal, noise and radiation effects implement the geophysical function. For example, the problem of natural background radiation arises, which is generally safe on the earth’s surface. However, in countries such as Brazil and India it can be hundreds of times higher than permissible. It is believed that its source is radon and its decay products, as well as certain types of human activity.

The geochemical function is associated with problems of chemical pollution harmful to humans and other representatives of the animal world. Various substances with toxic, carcinogenic and mutagenic properties enter the lithosphere.

They are safe when they are in the bowels of the planet. Zinc, lead, mercury, cadmium and others extracted from them heavy metals may pose a great danger. In processed solid, liquid and gaseous form, they enter the environment.

What is the Earth's crust made of?

Compared to the mantle and core, the Earth's crust is a fragile, hard and thin layer. It consists of relatively light matter, which includes about 90 natural elements. They are found in different places in the lithosphere and with varying degrees of concentration.

The main ones are: oxygen, silicon, aluminum, iron, potassium, calcium, sodium magnesium. 98 percent of the earth's crust consists of them. About half of this is oxygen, and over a quarter is silicon. Thanks to their combinations, minerals such as diamond, gypsum, quartz, etc. are formed. Several minerals can form a rock.

An ultra-deep well on the Kola Peninsula made it possible to get acquainted with mineral samples from a 12-kilometer depth, where rocks close to granites and shales were discovered.
The greatest thickness of the crust (about 70 km) was revealed under mountain systems. Under flat areas it is 30-40 km, and under the oceans it is only 5-10 km.
Much of the crust forms an ancient, low-density upper layer consisting primarily of granites and shales.
The structure of the earth's crust resembles the crust of many planets, including the Moon and their satellites.

By modern ideas Geology Our planet consists of several layers - geospheres. They differ in physical properties, chemical composition and In the center of the Earth there is a core, followed by the mantle, then the earth's crust, hydrosphere and atmosphere.

In this article we will look at the structure of the earth's crust, which is top part lithosphere. It is an outer solid shell whose thickness is so small (1.5%) that it can be compared to a thin film on the scale of the entire planet. However, despite this, it is the upper layer of the earth’s crust that is of great interest to humanity as a source of minerals.

The earth's crust is conventionally divided into three layers, each of which is remarkable in its own way.

Upper layer- sedimentary. It reaches a thickness of 0 to 20 km. Sedimentary rocks are formed due to the deposition of substances on land, or their settling at the bottom of the hydrosphere. They are part of the earth's crust, located in it in successive layers.
The middle layer is granite. Its thickness can vary from 10 to 40 km. This is an igneous rock that formed a solid layer as a result of eruptions and subsequent solidification of magma in the earth's thickness during high blood pressure and temperature.
The lower layer, which is part of the structure of the earth's crust, is basalt, also of magmatic origin. It contains higher amounts of calcium, iron and magnesium, and its mass is greater than that of granite rock.

The structure of the earth's crust is not the same everywhere. The oceanic crust and the continental crust have especially striking differences. Under the oceans the earth's crust is thinner, and under the continents it is thicker. It is thickest in mountainous areas.

The composition includes two layers - sedimentary and basalt. Below the basalt layer is the Moho surface, and behind it is the upper mantle. ocean floor has the most complex relief forms. Among all their diversity special place occupy huge mid-ocean ridges, in which young basaltic oceanic crust is born from the mantle. Magma has access to the surface through a deep fault - a rift, which runs along the center of the ridge along the peaks. Outside, the magma spreads, thereby constantly pushing the walls of the gorge to the sides. This process is called “spreading”.

The structure of the earth's crust is more complex on continents than under the oceans. The continental crust occupies a much smaller area than the oceanic crust - up to 40% of the earth's surface, but has a much greater thickness. Below it reaches a thickness of 60-70 km. The continental crust has a three-layer structure - a sedimentary layer, granite and basalt. In areas called shields, a granite layer is on the surface. As an example, it is made of granite rocks.

The underwater extreme part of the continent - the shelf, also has a continental structure of the earth's crust. It also includes the islands of Kalimantan, New Zealand, New Guinea, Sulawesi, Greenland, Madagascar, Sakhalin, etc. As well as internal and marginal seas: Mediterranean, Azov, Black.

It is possible to draw a boundary between the granite layer and the basalt layer only conditionally, since they have a similar speed of passage of seismic waves, which is used to determine the density of the earth’s layers and their composition. The basalt layer is in contact with the Moho surface. The sedimentary layer can have different thicknesses, depending on the landform located on it. In the mountains, for example, it is either absent altogether or has very small thickness, due to the fact that loose particles move down slopes under the influence of external forces. But it is very powerful in foothill areas, depressions and basins. So, it reaches 22 km.

The Earth's crust (lithosphere) is the upper shell of the Earth. There are two types of earth's crust: oceanic And continental (mainland). The coincidence of their boundaries with coastline The world ocean is observed over most of the latter, but there are also significant areas where they diverge. At the same time, the areas of continents located below sea level significantly predominate.

It is customary to distinguish three layers in the composition of the bark - the upper sedimentary, average granite and lower basaltic(Fig. 1.9).

Rice. 1.9.

The identification of layers is based on geophysics data on the speed of seismic waves. Sedimentary and granite layers are not widespread; basalt layers are present everywhere. The names of the two lower layers should not be taken literally. There are rocks there with seismic wave velocities corresponding to granites and basalts. In reality, there may be other breeds, similar or not similar to them.

The separation of granite and basalt layers during well drilling has not been confirmed in many cases. Wells buried in granites, instead of the granite-basalt boundary, revealed granites, gneisses or some other rocks. Basalts were repeatedly exposed only where the granite layer was completely absent. As a result, the question arose about the legality of identifying a granite layer, and this question remains open, but geologists do not abandon the three-layer structure of the earth’s crust.

Two types of earth's crust - oceanic crust and continental crust are distinguished on the basis of geophysical data. The oceanic crust is thinner and is 5-15 km (average 10 km), and lacks a granite layer. The continental crust is thicker - 30-40 km (occasionally up to 80 km). The connection between the two types of crust and the presence of land and oceans is clear in some places, but not in others. The thicker continental crust is more submerged in the mantle and is more uplifted, protruding above sea level.

The continental crust is less dense and seems to float on the surface of the mantle, preserving for billions of years. The oceanic crust is denser, its sections are drawn into the convective movement of mantle matter, i.e. in some places they sink into the mantle and melt there. In other places, mantle material rises to the surface, solidifies, and new oceanic crust grows (Fig. 1.10).

Therefore, in the oceans (on the oceanic crust) sediments older than 250 million years are not found.

Rice. 1.10.

The figure shows that at the site of ascent the thickness of the oceanic crust is minimal, and at the site of descent it is maximum. The continental crust does not participate in convection.

The parts of the continents that fall below ocean level are called shelf. The depth of the sea within the shelf usually does not exceed 200 m. Currently, for example, the shelf includes the North Atlantic and a significant part of the North Arctic Ocean(bottom of the Northern, Baltic, White, Kara, East Siberian seas, Laptev Sea, East China Sea), strip Atlantic Ocean near the southern coast of Argentina, the space between Australia and Indochina, vast areas around New Zealand and Antarctica.

In the geological past, shelf sea conditions regularly appeared on the continents in one place or another. This is indicated by the presence of a sedimentary layer - a cover marine rocks, widespread across continents. For example, in Moscow the thickness of the cover is about 1.5 km.

It is believed that in the geological past, land and sea regularly replaced each other here, and the land existed approximately

2/3, and the sea 1/3 of the time, the continental type of crust was preserved (Fig. 1.11).

Rice. 1.11.

There are few areas of oceanic crust that rise above sea level and form land - the island of Iceland and a few small islands in the Pacific Ocean. According to modern ideas, the main structures of the earth's crust are the so-called lithospheric plates - areas of the earth's crust that undergo independent horizontal movements. The current location of lithospheric plates is shown in Fig. 1.12.

Rice. 1.12.

7 - Eurasian (/, A- Chinese; 1,6 - Iranian; 1, in- Turkish; 1,g- Hellenic; 1, d- Adriatic); 2 - African (2, A- Arabian); 3 - Indo-Australian (3, A- Fiji; 3,6 - Solomonova); 4 - Pacific ( 4, a- Nazca; 4,6 - Coconut; 4, in- Caribbean; 4, g- Proud; 4, d- Philippine; 4, e- Bismarck); 5 - American (5, A- North American; 5 B- South American);

b - Antarctic

The speed of movement of lithospheric plates is up to several centimeters per year, the total movements in geological time are many thousands of kilometers horizontally. A lithospheric plate can consist either of only a piece of continental or oceanic crust, or of a combined section of both crusts. In many places where lithospheric plates contact, increased tectonic, volcanic and other activity is observed.

Test questions and assignments

1. Tell us about the origin of the Universe and the Earth.
2. Describe the structure of the solar system.
3. Based on what methods are ideas about the structure of the Earth formed?
4. What are geophysical methods for studying the deep structure of the Earth?
5. What are the shape, size, density, chemical composition of the Earth?
6. What is the structure of the Earth according to geophysical data?
7. Name the main types of the earth's crust. What is a shelf?
8. What are sedimentary, granite and basalt layers?

All described types of rocks participate in the structure of the earth's crust - igneous, sedimentary and metamorphic, occurring above the Moho boundary. Both within the continents and within the oceans, mobile belts and relatively stable areas of the earth's crust are distinguished. On continents, stable areas include vast flat spaces - platforms (East European, Siberian), within which the most stable areas are located - shields (Baltic, Ukrainian), which are outcrops of ancient crystalline rocks. Mobile belts include young mountain structures, such as the Alps, Caucasus, Himalayas, Andes and others (Figure 3.1).

Figure 3.1. Generalized profile of the ocean floor (according to O. K. Leontiev)

Continental structures are not limited only to continents; in some cases they extend into the ocean, forming the so-called underwater margin of continents, consisting of a shelf, up to 200 m deep, a continental slope with a foot to depths of 2500 -3000 m. Stable areas are also distinguished within the oceans - ocean platforms - significant areas of the ocean floor - vast abyssal (Greek "abyssos" - abyss) plains 4-6 km deep, and mobile belts, which include mid-ocean ridges and active margins Pacific Ocean with developed marginal seas(Okhotsk, Japanese, etc.), island arcs (Kuril, Japanese, etc.) and deep-sea trenches (8-10 km deep or more).

At the first stages of geophysical research, two main types of the earth's crust were distinguished: 1) continental and 2) oceanic, sharply different from each other in the structure and thickness of the constituent rocks. Subsequently, two transitional types began to be distinguished: 1) subcontinental and 2) suboceanic (Figure 3.2).

Legend:

1 - water; 2 - sedimentary layer; 3 - granite layer; 4 - basalt layer of continental crust; 5 - basalt layer of oceanic crust; 6 - magmatic layer of oceanic crust; 7 - volcanic islands; 8.9 - mantle (ultrabasic igneous rocks).

Figure 3.2 - Structure diagram various types earth's crust

Continental type of earth's crust

Continental type of earth's crust. The thickness of the continental crust varies from 35-40 (45) km within platforms to 55-70 (75) km in young mountain structures. The continental crust continues into the submarine margins of the continents. In the shelf area, its thickness decreases to 20-25 km, and on the continental slope (at a depth of about 2.0-2.5 km) it pinches out. The continental crust consists of three layers. The first - the uppermost layer is represented by sedimentary rocks, with a thickness of 0 to 5 (10) km within platforms, up to 15-20 km in tectonic troughs of mountain structures. The velocity of longitudinal seismic waves (Vp) is less than 5 km/s. The second - traditionally called "granite" layer is 50% composed of granites, 40% - gneisses and other to varying degrees metamorphosed rocks. Based on these data, it is often called granite-gneiss or granite-metamorphic. Its average thickness is 15-20 km (sometimes in mountain structures up to 20-25 km). Seismic wave speed (Vp) - 5.5-6.0 (6.4) km/s. The third, lower layer is called "basalt". In terms of average chemical composition and seismic wave speed, this layer is close to basalts.

However, it is suggested that it is composed of basic intrusive rocks such as gabbro, as well as metamorphic rocks of the amphibolite and granulite facies of metamorphism; the presence of ultrabasic rocks is not excluded. It is more correct to call this layer granulite-mafic (mafic is the main rock). Its thickness varies from 15-20 to 35 km. Wave propagation speed (Vp) 6.5-6.7 (7.4) km/s. The boundary between granite-metamorphic and granulite-mafic layers is called the Conrad seismic section. For a long time The prevailing idea was that the Conrad boundary existed everywhere in the continental crust. However, subsequent deep seismic sounding data showed that the Conrad surface is not expressed everywhere, but is recorded only in certain places. Naturally, new interpretations of the structure of the continental crust arise. Thus, N.I. Pavlenkova and others proposed a four-layer model (Fig. 3.3). This model identifies an upper sedimentary layer with a clear velocity boundary, designated Ko. The lower parts of the earth's crust are combined into the concept of a crystalline foundation, or consolidated crust, within which three layers are distinguished: upper, intermediate and lower, separated by the boundaries K1 and K2. There is sufficient stability of the K2 boundary - between the intermediate and lower floors. The upper floor is characterized by a vertically layered structure and differentiation of individual blocks in composition and physical parameters. For the intermediate floor, thin horizontal layering and the presence of individual plates with a reduced seismic wave velocity (Vp) - 6 km/s (with a total velocity in the layer of 6.4-6.7 km/s) and an anomalous density are noted.

Based on this, it is concluded that the intermediate layer can be classified as a weakened layer, along which horizontal movements of the substance are possible. Currently, other researchers are paying attention to the presence of individual lenses in the continental crust with relatively (0.1-0.2 km/s) reduced seismic wave velocities at depths of 10-20 km, with a lens power of 5-10 km. It is assumed that these zones (or lenses) are associated with strong fracturing and water content in the rocks.

S. R. Taylor's data also indicate that within the continental crust there is no single layer with a reduced velocity, but discontinuous layering is noted. All of the above indicates the great complexity of the continental crust and the ambiguity of its interpretation. Quite convincing evidence of this is the data obtained during ultra-deep drilling Kola well, which has already reached a depth of over 12 km. According to preliminary seismic data, in the area where the well was laid, the boundary between the “granite” and “basalt” layers should be encountered at a depth of about 7 km. In reality, there was no geophysical “basalt” layer. At this depth, under a thick metamorphosed volcanogenic-sedimentary strata of Proterozoic age, plagioclase gneisses, granite-gneisses, and amphibolites were discovered - rocks of the medium-temperature stage of metamorphism, the percentage of which increases with depth. What caused the change in the speed of seismic waves (from 6.1 to 6.5-6.6 km/s) at a depth of about 7 km, where the presence of a geophysical “basalt” layer was assumed? It is possible that this is due to amphibolites and their role in changing the elastic properties of rocks. It is also possible that the boundary indicated earlier (before drilling the well) is associated not with a change in the composition of the rocks, but with an increase in the stress field caused by intense deformations and repeated manifestations of metamorphism.

Introduction…………………………………………………………………………………..2

1. Structure of the Earth……………………………………………………………….3

2. Composition of the earth’s crust………………………………………………………...5

3.1. State of the Earth………………………………………………………...7

3.2.State of the earth’s crust……………………………………………………...8

List of used literature………………………….………………10

Introduction

The Earth's crust is the outer hard shell of the Earth (geosphere). Below the crust is the mantle, which differs in composition and physical properties- it is denser and contains mainly refractory elements. The crust and mantle are separated by the Mohorovicic boundary, or Moho for short, where there is a sharp increase in seismic wave velocities. From the outside most of The crust is covered by the hydrosphere, and the smaller one is influenced by the atmosphere.

There is a crust on most terrestrial planets, the Moon and many satellites of the giant planets. In most cases it consists of basalts. The Earth is unique in that it has two types of crust: continental and oceanic.

1. Structure of the Earth

Most of the Earth's surface (up to 71%) is occupied by the World Ocean. Average depth The world's oceans - 3900 m. The existence of sedimentary rocks whose age exceeds 3.5 billion years serves as evidence of the existence of vast bodies of water on Earth already at that distant time. On modern continents, plains are more common, mainly low-lying ones, and mountains - especially high ones - occupy a small part of the planet's surface, as well as deep-sea depressions at the bottom of the oceans. The shape of the Earth, as is known, is close to spherical, but with more detailed measurements it turns out to be very complex, even if we outline it with a flat ocean surface (not distorted by tides, winds, currents) and the conditional continuation of this surface under the continents. The irregularities are maintained by the uneven distribution of mass in the Earth's interior.

One of the features of the Earth is its magnetic field, thanks to which we can use a compass. Magnetic pole The Earth to which the northern end of the compass needle is attracted does not coincide with the North Geographic Pole. Under the influence of the solar wind, the Earth's magnetic field is distorted and acquires a “trail” in the direction from the Sun, which extends for hundreds of thousands of kilometers.

The internal structure of the Earth is, first of all, judged by the characteristics of the passage of mechanical vibrations through the various layers of the Earth that occur during earthquakes or explosions. Valuable information is also provided by measurements of the magnitude of the heat flow emerging from the depths, the results of determinations of the total mass, moment of inertia and polar compression of our planet. The mass of the Earth is found from experimental measurements of the physical constant of gravity and the acceleration of gravity. For the mass of the Earth, the value obtained is 5.967 1024 kg. Based on the whole complex scientific research a model was built internal structure Earth.

The solid shell of the Earth is the lithosphere. It can be compared to a shell covering the entire surface of the Earth. But this “shell” seems to have cracked into pieces and consists of several large lithospheric plates, slowly moving one relative to the other. The overwhelming number of earthquakes is concentrated along their boundaries. The upper layer of the lithosphere is the earth's crust, the minerals of which consist mainly of silicon and aluminum oxides, iron oxides and alkali metals. The earth's crust has an uneven thickness: 35-65 km on the continents and 6-8 km under the ocean floor. The upper layer of the earth's crust consists of sedimentary rocks, the lower layer of basalts. Between them there is a layer of granites, characteristic only of the continental crust. Under the crust is the so-called mantle, which has a different chemical composition and greater density. The boundary between the crust and mantle is called the Mohorovic surface. In it, the speed of propagation of seismic waves increases abruptly. At a depth of 120-250 km under the continents and 60-400 km under the oceans lies a layer of mantle called the asthenosphere. Here the substance is in a state close to melting, its viscosity is greatly reduced. All lithospheric plates seem to float in a semi-liquid asthenosphere, like ice floes in water. Thicker sections of the earth's crust, as well as areas consisting of less dense rocks, rise relative to other sections of the crust. At the same time, additional load on a section of the crust, for example, due to the accumulation of a thick layer of continental ice, as happens in Antarctica, leads to a gradual subsidence of the section. This phenomenon is called isostatic equalization. Below the asthenosphere, starting from a depth of about 410 km, the “packing” of atoms in mineral crystals is compacted under the influence of high pressure. The sharp transition was discovered by seismic research methods at a depth of about 2920 km. Starts here earth's core, or, more precisely, the outer core, since in its center there is another one - the inner core, the radius of which is 1250 km. The outer core is obviously in a liquid state, since transverse waves, which do not propagate in liquid, do not pass through it. The existence of a liquid outer core is associated with the origin magnetic field Earth. Inner core, apparently solid. At the lower boundary of the mantle, the pressure reaches 130 GPa, the temperature there is no higher than 5000 K. In the center of the Earth, the temperature may rise above 10,000 K.

2. Composition of the earth's crust

The earth's crust consists of several layers, the thickness and structure of which vary within the oceans and continents. In this regard, oceanic, continental and intermediate types of the earth's crust are distinguished, which will be described further.

Based on their composition, the earth's crust is usually divided into three layers - sedimentary, granite and basalt.

The sedimentary layer is composed of sedimentary rocks, which are the product of destruction and redeposition of material from the lower layers. Although this layer covers the entire surface of the Earth, it is so thin in places that one can practically speak of its discontinuity. At the same time, sometimes it reaches a power of several kilometers.

The granite layer is composed mainly of igneous rocks formed as a result of the solidification of molten magma, among which varieties rich in silica (acidic rocks) predominate. This layer, which reaches a thickness of 15-20 km on continents, is greatly reduced under the oceans and may even be completely absent.

The basalt layer is also composed of igneous material, but it is poorer in silica (basic rocks) and has a higher specific gravity. This layer is developed at the base of the earth's crust in all areas of the globe.

The continental type of the earth's crust is characterized by the presence of all three layers and is much thicker than the oceanic one.

The earth's crust is the main object of study of geology. The earth's crust consists of a very diverse range of rocks, consisting of equally diverse minerals. When studying a rock, first of all, its chemical and mineralogical composition is examined. However, this is not enough to fully understand the rock. Rocks can have the same chemical and mineralogical composition of various origins, and therefore various conditions occurrence and distribution.

The structure of a rock is understood as the size, composition and shape of the mineral particles composing it and the nature of their connection with each other. Distinguish different types structures depending on whether the rock is composed of crystals or an amorphous substance, what the size of the crystals is (whole crystals or fragments of them are included in the rock), what the degree of roundness of the fragments is, whether the mineral grains forming the rock are completely unconnected with each other or whether they are welded together in some way -or a cementing substance, directly fused with each other, sprouted each other, etc.

Texture refers to the relative arrangement of the components that make up the rock, or the way they fill the space occupied by the rock. An example of textures could be: layered, when the rock consists of alternating layers different composition and structures, schistose, when the rock easily breaks up into thin tiles, massive, porous, solid, vesicular, etc.

The form of occurrence of rocks refers to the shape of the bodies they form in the earth's crust. For some rocks these are layers, i.e. relatively thin bodies, limited by parallel surfaces; for others - cores, rods, etc.

The classification of rocks is based on their genesis, i.e. method of origin. There are three large groups of rocks: igneous, or igneous, sedimentary and metamorphic.

Igneous rocks are formed during the solidification of silicate melts located in the depths of the earth's crust under high pressure. These melts are called magma (from the Greek word for “ointment”). In some cases, magma penetrates into the thickness of the underlying rocks and solidifies at a greater or lesser depth, in others it solidifies, pouring out onto the surface of the Earth in the form of lava.

Sedimentary rocks are formed as a result of the destruction of pre-existing rocks on the Earth's surface and the subsequent deposition and accumulation of the products of this destruction.

Metamorphic rocks are the result of metamorphism, i.e. transformation of pre-existing igneous and sedimentary rocks under the influence of a sharp increase in temperature, an increase or change in the nature of pressure (change from confining pressure to oriented pressure), as well as under the influence of other factors.

3.1. State of the Earth

The state of the earth is characterized by temperature, humidity, physical structure And chemical composition. Human activities and the functioning of flora and fauna can improve or worsen the state of the earth. The main processes of impact on land are: irreversible withdrawal from agricultural activities; temporary seizure; mechanical impact; addition of chemical and organic elements; involvement of additional territories in agricultural activities (drainage, irrigation, deforestation, reclamation); heating; self-renewal.