Exogenous and endogenous processes. Characteristics and classification of exogenous processes

Geological processes are divided into endogenous and exogenous.

Endogenous processes - geological processes associated with the energy that occurs in the bowels of the Earth. These include tectonic movements earth's crust, magmatism, rock metamorphism and seismic activity. The main sources of energy for endogenous processes are heat and gravitational instability - the redistribution of material in the Earth's interior in terms of density (gravitational differentiation).

Endogenous processes include:

• - tectonic - diverse in direction and intensity of the movement of the earth's crust, causing its deformation (collapse into folds) or rupture of layers;
• - seismic - associated with earthquakes;
• - magmatic - associated with magmatic activity;
• - volcanic - associated with volcanic activity;
• - metamorphic - the process of transformation of rocks under the influence of pressure and temperature without the introduction or removal of chemical components;
• - skarn - metasomatic mineral and rock formation as a result of exposure to various rocks (mainly limestones and dolomites) of high-temperature solutions containing Fe, M?, Ca, 81, Al and other substances with a wide participation of volatile components (water , carbon dioxide, C1, B, C, etc.), and in a wide range of temperatures and pressures during the general evolution of solutions as the temperature decreases from alkaline to acidic;
• - greisen - metasomatic alteration of granite rocks under the influence of gases released from the cooling magma with the transformation of feldspars into light micas;
• - hydrothermal - deposits of metal ores (Au, Cu, Pb, Sn, XV, etc.) and non-metallic minerals (talc, asbestos, etc.), the formation of which is associated with the deposition or redeposition of ore matter from hot deep aqueous solutions, often associated with magma chambers cooling in the earth's crust.

Tectonic movements - mechanical movements the earth's crust, caused by forces acting in it and mainly in the Earth's mantle, and leading to deformation of the rocks that make up the crust. Tectonic movements are associated, as a rule, with a change in the chemical composition, phase state (mineral composition) and the internal structure of rocks undergoing deformation. Tectonic movements simultaneously cover very large areas.

Geodetic measurements show that almost the entire surface of the Earth is continuously in motion, however, the speed of tectonic movements is small, varies from hundredths to a few tens of millimeters per year, and only the accumulation of these movements during a very long (tens to hundreds of million years) geological time leads to to large total displacements of individual sections of the earth's crust.

The American geologist G. Gilbert proposed (1890), and the German geologist X. Stille developed (1919) a classification of tectonic movements with their division into epeirogenic, expressed in prolonged uplifts and subsidence of large areas of the earth's surface, and orogeny, manifested episodically (orogenic phases) in certain zones by the formation of folds and ruptures and leading to the formation of mountain structures. This classification is still used, but its main drawback is the combination of two fundamentally different processes in the concept of orogeny - folding and rupture formation, on the one hand, and mountain building, on the other. Other classifications have been proposed. One of them (domestic geologists A.P. Karpinsky, M.M. Tetyaev and others) provided for the allocation oscillatory folds and discontinuous tectonic movements, another (German geologist E. Harman and Dutch scientist R. W. van Bemmelen) - undation (wave) and undulation (folded) tectonic movements. It became clear that tectonic movements are very diverse both in the form of manifestation and in the depth of origin, and also, obviously, in the mechanism and causes of occurrence.

According to another principle, tectonic movements were divided by M.V. Lomonosov into slow (secular) and fast. Fast movements are associated with earthquakes and, as a rule, are distinguished by high speed, several orders of magnitude higher than the speed of slow movements. Displacements of the earth's surface during earthquakes amount to several meters, sometimes more than 10 m. However, such displacements appear sporadically.

The subdivision of tectonic movements into vertical (radial)) and horizontal (tangential), although it is largely conditional, since these movements are interconnected and pass one into another. Therefore, it is more correct to speak of tectonic movements with a predominant vertical or horizontal component. The prevailing vertical movements cause the rise and fall of the earth's surface, including the formation of mountain structures. They are the main reason for the accumulation of thick layers of sedimentary rocks in the oceans and seas, and partly on land. Horizontal movements are most clearly manifested in the formation of large shifts of individual blocks of the earth's crust relative to others with an amplitude of hundreds and even thousands of kilometers, in their thrusts with an amplitude of hundreds of kilometers, as well as in the formation of oceanic depressions thousands of kilometers wide as a result of the separation of blocks of continental crust.

Tectonic movements are distinguished by a certain periodicity or unevenness, which is expressed in changes in sign and (or) speed in time. Relatively short-period vertical movements with a frequent change of sign (reversible) are called oscillatory. Horizontal movements usually retain their direction for a long time and are irreversible. Oscillatory tectonic movements are likely to cause transgressions and regressions sea, the formation of sea and river terraces.

By the time of manifestation, the latest tectonic movements are distinguished, which are directly reflected in the modern relief of the Earth and therefore are recognized not only by geological, but also by geomorphological methods, and modern tectonic movements, which are also studied by geodetic methods (re-leveling, etc.). They are the subject of research in modern tectonics.

The tectonic movements of the remote geological past are established by the distribution of transgressions and regressions of the ocean, by the total thickness (thickness) of accumulated sedimentary deposits, by the distribution of their facies and sources of clastic material carried in the depression. In this way, the vertical component of the movement of the upper layers of the earth's crust or the surface of a consolidated basement located under the sedimentary cover is determined. The level of the World Ocean is used as a benchmark, which is considered almost constant, with possible deviations of up to 50-100 m during melting or the formation of glaciers, as well as more significant - up to several hundred meters as a result of a change in the capacity of oceanic depressions during their growth and the formation of mid-ocean basins. ridges.

Large horizontal displacements, which are not recognized by all scientists, are established both from geological data, by graphic straightening of folds and restoring thrust rock strata in their original position, and on the basis of studying the remanent magnetization of rocks and changes in paleoclimate. It is believed that with a sufficient amount of paleomagnetic and geological data, it is possible to restore the former location of the continents and oceans and determine the speed and direction of movements that occurred in subsequent times, for example, from the end of the Paleozoic era.

The rate of horizontal movements is determined by supporters of mobilism by the width of the newly formed oceans (Atlantic, Indian), by paleomagnetic data indicating changes in latitude and orientation with respect to the meridians, and by the width of magnetic anomaly bands of various signs formed during the growth of the ocean floor, which are compared with the duration of epochs. different polarity magnetic field Earth. These estimates, as well as the speed of modern horizontal movements, measured by geodetic methods in rifts (East Africa), folded areas (Japan, Tajikistan) and in slips (California), are 0.1-10 cm/g. Over millions of years, the speed of horizontal movements changes slightly, the direction remains almost constant.

Vertical movements, on the contrary, have a variable, oscillatory character. Repeated levelings show that the rate of subsidence or uplift on the plains usually does not exceed 0.5 cm/year, while the rise in mountainous areas (for example, in the Caucasus) reaches 2 cm/year. At the same time, the average rates of vertical tectonic movements determined for large time intervals (for example, over tens of millions of years) do not exceed 0.1 cm/year in mobile belts and 0.01 cm/year on platforms. This difference in velocities measured over short and long periods of time indicates that only the integral result of secular vertical movements is recorded in geological structures, which accumulates when oscillations of the opposite sign are summed.

The similarity of tectonic movements repeating on the same tectonic structures, allows us to speak about the inherited nature of vertical tectonic movements. Tectonic movements usually do not include the movement of rocks in the near-surface zone (tens of meters from the surface), caused by violations of their gravitational balance under the influence of exogenous (external) geological processes, as well as periodic rises and falls of the earth's surface, due to solid tides of the Earth due to the attraction of the Moon and Sun. It is disputable to attribute to tectonic movements the processes associated with the restoration of isostatic equilibrium, for example, uplifts during the reduction of large ice sheets such as the Antarctic or Greenland. The movements of the earth's crust caused by the activity of volcanoes are of a local nature. The causes of tectonic movements have not yet been reliably established; various assumptions have been made in this regard.

According to a number of scientists, deep tectonic movements are caused by a system of large convection currents covering the upper and middle layers of the Earth's mantle. Such currents are apparently associated with the expansion of the earth's crust in the oceans and compression in folded areas, above those zones where the approach and subsidence of counter currents occurs. Other scientists (V. V. Belousov) deny the existence of closed convection currents in the mantle, but allow the rise of the mantle heated in the lower parts and lighter products of its differentiation, causing upward vertical movements of the crust. The cooling of these masses causes it to sink. At the same time, no significant significance is attached to horizontal movements, and they are considered derivatives of vertical ones. When elucidating the nature of movements and deformations of the earth's crust, some researchers assign a certain role to stresses arising in connection with changes in the speed of the earth's rotation, while others consider them too insignificant.

The deep heat of the Earth is predominantly of radioactive origin. The continuous generation of heat in the bowels of the Earth leads to the formation of its flow directed to the surface. At some depths, with a favorable combination of material composition, temperature, and pressure, foci and layers of partial melting may appear. Such a layer in the upper mantle is the asthenosphere - the main source of magma formation; convection currents can arise in it, which serve as a presumed cause of vertical and horizontal movements of the lithosphere. In the zones of volcanic belts of island arcs and continental margins, the main chambers of magma are associated with superdeep inclined faults (the Zavaritsky-Benioff zones) extending under them from the ocean (approximately to a depth of 700 km). Under the influence of a heat flow or directly from the heat brought by rising deep magma, the so-called crustal magma chambers arise in the earth's crust itself; reaching the near-surface parts of the crust, magma intrudes into them in the form of intrusions of various shapes or pours out to the surface, forming volcanoes.

Gravitational differentiation led to the stratification of the Earth into geospheres of different density. On the surface of the Earth, it also manifests itself in the form of tectonic movements, which, in turn, lead to tectonic deformations of the rocks of the earth's crust and upper mantle. The accumulation and subsequent discharge of tectonic stresses along active faults lead to earthquakes.

Both types of deep processes are closely related: radioactive heat, by lowering the viscosity of the material, promotes its differentiation, and the latter accelerates the removal of heat to the surface. It is assumed that the combination of these processes leads to non-uniformity in time of the removal of heat and light matter to the surface, which, in turn, can be explained by the presence of tectonomagmatic cycles in the history of the earth's crust.

Tectonic cycles(stages) - large (more than 100 million years) periods geological history Lands characterized by a certain sequence of tectonic and general geological events. They are most clearly manifested in the mobile areas of the Earth, where the cycle begins with subsidence of the earth's crust with the formation of deep sea basins, the accumulation of thick layers of sediments, underwater volcanism, and the formation of basic and ultrabasic intrusive-magmatic rocks. Island arcs appear, andesitic volcanism manifests itself, the sea basin is divided into smaller ones, and fold-thrust deformations begin. Then there is the formation of folded and fold-cover mountain structures, bordered and separated by advanced (marginal, foothill) and intermountain troughs, which are filled with mountain destruction products - maupasses. This process is accompanied by regional metamorphism, granite formation, and liparitic-basaltic ground volcanic eruptions.

A similar sequence of events is also observed on the platforms: a change in continental conditions due to the transgression of the sea, and then again regression and the establishment of a continental regime with the formation of weathering crusts, with a corresponding change in the type of sediments - first continental, then lagoonal, often saline or coal-bearing, then marine clastic, in the middle of the cycle predominantly carbonate or siliceous, at the end again marine, lagoonal (salt) and continental (sometimes glacial).

Intense fold-and-thrust deformations and mountain building in some mobile zones often correspond to the formation of new subsidence zones in their rear and the formation of rift systems - aulacogens on platforms.

The average duration of tectonic cycles in the Phanerozoic is 150-180 Ma (in the Precambrian, tectonic cycles were apparently longer). Along with such cycles, larger ones are sometimes distinguished - megacycles (megastages) - lasting hundreds of millions of years. In Europe, partly in North America and Asia, the following cycles were established in the Late Precambrian and Phanerozoic: Grenville (Middle Riphean); Baikal (Late Riphean-Vendian); Caledonian (Cambrian-Devonian); Hercynian (Devonian-Permian); Cimmerian or Mesozoic (Triassic-Jurassic); alpine (Cretaceous-Cenozoic).

The original schematic representation of tectonic cycles as being strictly synchronous on the scale of the entire planet, repeating everywhere and differing in the same complex of phenomena, is still rightly disputed. In fact, the end of one and the beginning of another cycle often turn out to be synchronous (in different, often adjacent regions). In each individual mobile system, usually one or two cycles are most fully expressed, immediately preceding its transformation into a folded system. mountain system, and the earlier ones are distinguished by the incompleteness of the set of phenomena characteristic of them, which sometimes merge with each other. On the scale of the entire history of the Earth, tectonic cyclicity acts only as a complication of its general directed development. Separate cycles form the stages of megacycles, and they, in turn, are major stages in the history of the Earth as a whole. The reasons for the cyclicity have not yet been established. Assumptions are made about the periodic accumulation of heat and an increase in the heat flow emanating from the deep bowels of the Earth, about the cycles of rise or circulation (convection) of the products of differentiation of the mantle substance, etc.

Spatial irregularities of the same deep processes are used to explain the division of the earth's crust into more or less geologically active regions, for example, into mountain-folded areas and platforms.

The formation of the Earth's relief and the formation of many important minerals are associated with endogenous processes.

Exogenous processes - geological processes caused by energy sources external to the Earth (mainly solar radiation) in combination with gravity. Exogenous processes occur on the surface and in the near-surface zone of the earth's crust in the form of its mechanical and physico-chemical interaction with the hydrosphere and atmosphere. These include sedimentation and the formation of deposits of sedimentary minerals, weathering, geological activity of the wind (eolian processes, deflation), flowing surface and ground waters (erosion, denudation), lakes and swamps, waters of the seas and oceans (abrasion), glaciers (exaration) .

Exogenous processes include different types of weathering in the form destruction:

• - deflationary - blowing, turning and grinding of rocks with mineral particles carried by the wind;
• - mudflows - formation and movement of mud or mud-rock flows;
• - erosion - erosion of soils and rocks by water flows;

or different processes accumulation rainfall:

• - alluvial - deposits of rivers in the form of sand, pebbles, conglomerates;
• - deluvial - the movement of weathering products of rocks down the slope under the influence of gravity, rain and melt water;
• - colluvial - displacement of slope debris under the influence of gravity;
• - landslide - separation of land masses and rocks and their movement along the slope under the influence of gravity;
• - sediment-forming - precipitation from water, air (in calm areas) or on slopes under the action of gravity;
• - proluvial - movement of products of destruction of rocks by temporary flows and their deposition at the foot of the mountains, often in the form of alluvial fans;
• - ore-forming - accumulation of ore substance under the action of different reasons: native gold - as a result of precipitation from water streams, aluminum oxides - precipitation from aqueous solutions, etc.;
• - eluvial - products of destruction of rocks remain at the place of their formation.

Weathering- the process of destruction and change of rocks in the conditions of the earth's surface as a result of the mechanical and chemical effects of the atmosphere, ground and surface waters and organisms. According to the nature of the environment in which weathering occurs, it can be atmospheric and underwater. By the nature of the impact of weathering on rocks, there are physical weathering, leading only to the mechanical disintegration of the rock into fragments; chemical weathering, in which the chemical composition of the rock changes with the formation of minerals that are more stable in the conditions of the earth's surface; organic (biological) weathering, reduced to mechanical fragmentation or chemical change of the rock as a result of the vital activity of organisms. A specific type of weathering is soil formation, in which a particularly active role is played by biological factors. Weathering of rocks occurs under the influence of water (precipitation and ground water), carbon dioxide and oxygen, water vapor, atmospheric and ground air, seasonal and daily temperature fluctuations, vital activity of macro- and microorganisms and their decomposition products. The speed and degree of weathering, the thickness of the resulting weathering products and their composition, in addition to the listed agents, are also affected by relief and geological structure terrain, composition and structure of parent rocks. The vast majority of physical and chemical weathering processes (oxidation, sorption, hydration, coagulation) occur with the release of energy. Usually, the types of weathering act simultaneously, but depending on the climate, one or another of them predominates.

Physical weathering occurs mainly in dry and hot climates and is associated with sharp fluctuations in the temperature of rocks when heated by sunlight (insolation) and subsequent cooling at night; a rapid change in the volume of the surface parts of the rocks leads to their cracking. In areas with frequent temperature fluctuations around 0 °C, mechanical destruction of rocks occurs under the influence of frost weathering; when the water that has penetrated into the cracks freezes, its volume increases and the rock breaks.

Chemical and organic types of weathering are characteristic mainly of layers with a humid climate. The main factors of chemical weathering are air and especially water containing salts, acids and alkalis. Aqueous solutions circulating in the rock mass, in addition to simple dissolution, are also capable of producing complex chemical changes.

The physical and chemical processes of weathering occur in close relationship with the development and vital activity of animals and plants and the action of their decay products after death. The most favorable conditions for the formation and preservation of weathering products (minerals) are the conditions of a tropical or subtropical climate and slight erosional dissection of the relief. At the same time, the thickness of rocks subjected to weathering is characterized (in the direction from top to bottom) by geochemical zoning, expressed by a complex of minerals characteristic of each zone. The latter are formed as a result following friend after another process: the disintegration of rocks under the influence of physical weathering, leaching of bases, hydration, hydrolysis and oxidation. These processes often go up to the complete decomposition of primary minerals, up to the formation of free oxides and hydroxides.

Depending on the degree of acidity - alkalinity of the environment, as well as the participation of biogenic factors, minerals of various chemical compositions are formed: from stable in an alkaline environment (in the lower horizons) to stable in an acidic or neutral environment (in the upper horizons). The diversity of weathering products represented by various minerals is determined by the composition of minerals in primary rocks. For example, on ultrabasic rocks (serpentinites), the upper zone is represented by rocks in the cracks of which carbonates (magnesite, dolomite) are formed. This is followed by horizons of carbonatization (calcite, dolomite, aragonite), hydrolysis, which is associated with the formation of nontronite and the accumulation of nickel (Niu up to 2.5%), silicification (quartz, opal, chalcedony). The zone of final hydrolysis and oxidation is composed of hydrogoethite (ocherous), goethite, magnetite, manganese oxides and hydroxides (nickel- and cobalt-containing). Weathering processes are associated with large deposits of nickel, cobalt, magnesite and naturally alloyed iron ores.

In those cases where weathering products do not remain at the site of their formation, but are carried away from the surface of weathered rocks by water or wind, peculiar relief forms often arise, depending both on the nature of weathering and on the properties of rocks, in which the process, as it were, manifests and emphasizes the features of their structure (Fig. 15).

Rice. 15.

Russia (TSB).

Igneous rocks (granites, diabases, etc.) are characterized by massive rounded forms of weathering; for layered sedimentary and metamorphic - stepped (cornices, niches, etc.). The heterogeneity of rocks and the unequal resistance of their various sections against weathering leads to the formation of remnants in the form of isolated mountains, pillars (Fig. 16), towers, etc.

In a humid climate, on inclined surfaces of homogeneous, relatively easily water-soluble rocks, such as limestone, flowing water corrodes irregular shape recesses separated by sharp protrusions and ridges, resulting in the formation uneven surface, known as carr.

Rice. sixteen.

the Yenisei River near Krasnoyarsk (TSB).

In the process of regeneration of residual weathering products, many soluble compounds are formed, which are carried by groundwater into water basins and enter into the composition of dissolved salts or precipitate. Weathering processes lead to the formation of various sedimentary rocks and many minerals: kaolins, ocher, refractory clays, sands, ores of iron, aluminum, manganese, nickel, cobalt, placers of gold, platinum, etc., oxidation zones of pyrite deposits with their minerals and others

Deflation(from late lat. With1 e/1 aio- blowing, blowing off) - waving, destruction of rocks and soils under the influence of wind, accompanied by the transfer and grinding of torn off particles. Deflation is especially strong in deserts, in those parts of them from which prevailing winds blow (for example, in the southern part of the Karakum desert). The combination of deflation and physical weathering processes leads to the formation of chiseled rocks of bizarre shape in the form of towers, columns, obelisks, etc.

soil erosion- destruction of soil by water and wind, movement of destruction products and their redeposition.

Education eolian landforms occurs under the influence of wind mainly in areas with an arid climate (deserts, semi-deserts); it is also found along the shores of seas, lakes and rivers with a sparse vegetation cover that is not able to protect loose and weathered rocks of the substrate from the action of the wind. Most common accumulative and accumulative-deflationary forms, formed as a result of the movement and deposition of sand particles by the wind, as well as developed (deflationary) eolian landforms arising due to blowing (deflation) loose weathering products, destruction of rocks under the influence of dynamic impacts of the wind itself and especially under the impact of small particles carried by the wind in the wind-sand flow.

The shape and size of accumulative and accumulative-deflationary formations depend on the wind regime (strength, frequency, direction, structure of the wind flow) that prevailed in the area and acted in the past, on the saturation of the wind sand flow with sand particles, the degree of connectivity of the loose substrate with vegetation, on moisture and other factors, as well as the nature of the underlying relief. Biggest Influence the appearance of aeolian landforms in sandy deserts is affected by the regime active winds, acting similarly to a water flow with turbulent motion of the medium near a solid surface. For medium- and fine-grained dry sand (with a grain diameter of 0.5-0.25 mm), the minimum active wind speed is 4 m/s. Accumulative and deflationary-accumulative forms, as a rule, move in accordance with the seasonally dominant wind direction: progressively with the annual impact of active winds of one or close directions; oscillatory and oscillatory-translationally, if the directions of these winds change significantly during the year (to opposite, perpendicular, etc.). Particularly intensive (at a speed of up to several tens of meters per year) is the movement of bare sandy accumulative forms.

Accumulative and deflationary-accumulative eolian landforms of deserts are characterized by the simultaneous presence of superimposed forms of several categories of magnitudes: 1st category - wind ripples, height from fractions of a millimeter to 0.5 m, distance between crests from a few millimeters to 2.5 m; 2nd category - thyroid accumulations with a height of at least 40 cm; 3rd category - dunes up to 2-3 m high, connected in a ridge longitudinal to the winds or in a dune chain transverse to the winds; 4th category - dune relief up to 10-30 m high; 5th and 6th categories - large forms (up to 500 m high), formed mainly by ascending air currents. In the deserts of the temperate zone, where vegetation plays an important role, which restrains the work of the wind, relief formation is slower and the largest forms do not exceed 60–70 m; 20 m

Since the prevailing wind regime (trade wind, monsoon-breeze, cyclonic, etc.) and the strength of the loose substrate are primarily determined by zonal-geographical factors, accumulative and accumulative-deflationary eolian landforms are generally distributed zonally. According to the classification proposed by the geographer B. A. Fedorovich, bare, easily mobile sandy forms are characteristic mainly of tropical extra-arid deserts (Sahara, deserts of the Arabian Peninsula, Iran, Afghanistan, Takla-Makan); semi-overgrown, weakly mobile - mainly for extratropical deserts (deserts Central Asia and Kazakhstan, Dzungaria, Mongolia, Australia); overgrown mostly immobile dune forms - for non-desert territories (mainly ancient glacial regions of Europe, Western Siberia, North America). A detailed classification of accumulative and deflationary-accumulative eolian landforms depending on the wind regime is given in the description of dunes and dunes.

Among the developed microforms (up to several tens of centimeters in diameter), the most common lattice or honeycomb rocks, composed mainly of terrigenous rocks; among the forms medium size(meters and tens of meters) - yardangs, hollows, boilers and blowing niches, bizarre rocks(mushroom, ring etc.), clusters of which often form entire aeolian "cities"; large developed forms (several kilometers across) include blowing basins and saline-deflationary depressions, formed under the combined action of intense processes of physicochemical (salt) weathering and deflation (including vast areas up to hundreds of kilometers; for example, the Karagie depression in Western Kazakhstan). A comprehensive study of eolian landforms, their morphology, origin, and dynamics is of great importance in the economic development of deserts.

Abrasion(from lat. ahayayu- scraping, shaving) - destruction by waves and surf of the shores of the seas, lakes and large reservoirs. The intensity of abrasion depends on the degree of wave action of the reservoir. The most important condition, predetermining the abrasion development of the coast, is a relatively steep angle of the initial slope (more than 1 °) of the coastal part of the bottom of the sea or lake. Abrasion creates an abrasion terrace, or bench, and an abrasion ledge, or cliff on the banks (Fig. 17). The sand, gravel, and pebbles formed as a result of the destruction of rocks can be involved in the processes of sediment movement and serve as material for coastal accumulative forms. Part of the material is carried by waves and currents to the foot of the abrasion underwater slope and forms a leaning accumulative terrace here. As the abrasion terrace expands, the abrasion gradually fades (because the shallow water zone expands, overcoming which the wave energy is spent) and, with the influx of sediments, can be replaced by accumulation. On the slopes of artificial reservoirs, the slopes of which in the past were formed by other, non-abrasive factors, the rate of abrasion is especially high - up to ten meters per year.

Rice. 17.

K - cliff; AT - abrasion terrace (bench); PAT - underwater accumulative terrace; SW - water level. The dotted line indicates the pre-abrasion relief (BSE).

Exaration(from late lat. ehagayo- plowing) - glacial plowing, the destruction of the rocks that make up its bed by the glacier, and the removal of destruction products (sloughs, boulders, pebbles, sand, clay, etc.) by a moving glacier. As a result of exaration, troughs, lake basins, “lamb foreheads”, “curly rocks”, glacial scars, and hatching appear. Along with the destruction of rocks, they are smoothed, polished and polished.

The main forms of manifestation of exogenous processes on the surface of the Earth:

• - the destruction of rocks and the chemical transformation of the minerals that compose them (physical, chemical, organic weathering);
• - removal and transfer of loosened and soluble products of destruction of rocks by water, wind and glaciers;
• - deposition (accumulation) of these products in the form of sediments on land or at the bottom of water basins and their gradual transformation into sedimentary rocks as a result of successive processes of sedimentogenesis, diagenesis and catagenesis.

Exogenous processes in combination with endogenous ones are involved in the formation of the Earth's relief, in the formation of sedimentary rock strata and related mineral deposits. For example, under conditions of manifestation of specific processes of weathering and sedimentation, ores of aluminum (bauxites), iron, nickel, etc. are formed; placers of gold and diamonds are formed as a result of selective deposition of minerals by water flows; under conditions conducive to the accumulation organic matter and strata of sedimentary rocks enriched with it, combustible minerals arise.

Geological processes are processes that change the composition, structure, relief and deep structure of the earth's crust. Geological processes, with a few exceptions, are characterized by scale and long duration (up to hundreds of millions of years); in comparison with them, the existence of mankind is a very brief episode in the life of the Earth. In this regard, the vast majority of geological processes are directly inaccessible to observation. They can only be judged by the results of their impact on certain geological objects - rocks, geological structures, types of relief of continents and the bottom of the oceans. Of great importance are observations of modern geological processes, which, according to the principle of actualism, can be used as models that make it possible to cognize the processes and events of the past, taking into account their variability. At present, a geologist can observe different stages of the same geological processes, which greatly facilitates their study.

All geological processes occurring in the bowels of the Earth and on its surface are divided into endogenous and exogenous. Endogenous geological processes occur due to the internal energy of the Earth. According to modern concepts (Sorokhtin, Ushakov, 1991), the main planetary source of this energy is the gravitational differentiation of terrestrial matter. (Components with increased specific gravity under the influence of gravitational forces tend to the center of the Earth, while lighter ones are concentrated near the surface). As a result of this process, a dense iron-nickel core stood out in the center of the planet, and convective currents arose in the mantle. A secondary source of energy is the energy of radioactive decay of matter. It accounts for only 12% of the energy used for the tectonic development of the Earth, and 82% for gravitational differentiation. Some authors believe that the main source of energy for endogenous processes is the interaction of the outer core of the Earth, which is in a molten state, with inner core and mantle. The endogenous processes are tectonic, igneous, pneumatolithic-hydrothermal and metamorphic.

Tectonic processes are called processes, under the influence of which tectonic structures of the earth's crust are formed - mountain-fold belts, deflections, depressions, deep faults, etc. Vertical and horizontal movements of the earth's crust are also related to tectonic processes.

Magmatic processes (magmatism) is a set of all geological processes associated with the activity of magma and its derivatives. Magma- a fiery-liquid molten mass that forms in the earth's crust or upper mantle and turns into igneous rocks when solidified. By origin, magmatism is divided into intrusive and effusive. The term "intrusive magmatism" combines the processes of formation and crystallization of magma at depth with the formation of intrusive bodies. Effusive magmatism (volcanism) is a set of processes and phenomena associated with the movement of magma from the depths to the surface with the formation of volcanic structures.

In a special group are hydrothermal processes. These are the processes of formation of minerals as a result of their deposition in cracks or pores of rocks from hydrothermal solutions. Hydrotherms - liquid hot aqueous solutions circulating in the earth's crust and participating in the processes of movement and deposition of mineral substances. Hydrothermal fluids are often more or less enriched in gases; if the content of gases is high, then such solutions are called pneumatolytic-hydrothermal. Currently, many researchers believe that hydrothermal fluids are formed by the mixing of deep circulation groundwater and juvenile waters formed during the condensation of magma water vapor. Hydrothermal fluids move along cracks and voids in rocks in the direction of lower pressure - to the earth's surface. Being weak solutions of acids or alkalis, hydrotherms are characterized by high chemical activity. As a result of the interaction of hydrotherms with host rocks, minerals of hydrothermal origin are formed.

Metamorphism - a complex of endogenous processes that cause changes in the structure, mineral and chemical composition of rocks under conditions of high pressure and temperature; melting of rocks does not occur. The main factors of metamorphism are temperature, pressure (hydrostatic and unidirectional) and fluids. Metamorphic changes consist in the decay of the original minerals, in molecular rearrangement and the formation of new minerals that are more stable under given environmental conditions. All types of rocks undergo metamorphism; the resulting rocks are called metamorphic.

Exogenous processes – geological processes occurring due to external sources of energy, mainly the Sun. They occur on the surface of the Earth and in the uppermost parts of the lithosphere (in the zone of action of factors hypergenesis or weathering). Exogenous processes include: 1) mechanical crushing of rocks to their constituent mineral grains, mainly under the influence of daily air temperature differences and due to frost weathering. This process is called physical weathering; 2) chemical interaction of mineral grains with water, oxygen, carbon dioxide and organic compounds, leading to the formation of new minerals - chemical weathering; 3) the process of moving weathering products (the so-called transfer) under the influence of gravity, by means of moving water, glaciers and wind in the area of ​​sedimentation (ocean trenches, seas, rivers, lakes, low relief); 4) accumulation strata of sediments and their transformation due to compaction and dehydration into sedimentary rocks. During these processes deposits of sedimentary minerals are formed.

The variety of forms of interaction between exogenous and endogenous processes determines the diversity of the structures of the earth's crust and the topography of its surface. Endogenous and exogenous processes are inextricably linked with each other. In essence, these processes are antagonistic, but at the same time inseparable, and this whole complex of processes can be conditionally called geological form of motion of matter. It has also recently included human activities.

During the last century, there has been an increase in the role of the technogenic (anthropogenic) factor in the composition of the general complex of geological processes. Technogenesis- a set of geomorphological processes caused by human production activities. According to the direction, human activity is divided into agricultural, exploitation of mineral deposits, construction of various structures, defense and others. The result of technogenesis is the technogenic relief. The boundaries of the technosphere are constantly expanding. So, the depth of drilling for oil and gas on land and shelf is increasing. The filling of reservoirs in mountainous seismically dangerous areas in some cases causes artificial earthquakes. Mining is accompanied by the release of huge volumes of “waste” rocks onto the day surface, as a result, a “lunar” landscape is created (for example, in the area of ​​the cities of Prokopyevsk, Kiselevsk, Leninsk-Kuznetsky and other cities of Kuzbass). Dumps of mines and other industries, garbage dumps create new forms of man-made relief, capturing an increasing part of agricultural land. The reclamation of these lands is carried out very slowly.

Thus, human economic activity has now become an integral part of all modern geological processes.

Endogenous are internal processes; exogenous - external, surface, for them the source of energy is the energy of the Sun and gravity (the gravitational field of the Earth).

Endogenous processes include:

Magmatism (from the word magma) is the process associated with the birth, movement and transformation of magma into igneous rock;

Tectonics (tectonic movements) - any mechanical movements of the earth's crust - uplifts, lowerings, horizontal movements, etc.;

Earthquakes - are the result of tectonic movements, but are usually considered independently;

Metamorphism - processes that lead to a change in the composition, structure of rocks inside the Earth with a change in physico-chemical parameters (pressure, temperature, etc.).

Exogenous processes include processes occurring on the surface or near it, changing the face of the Earth and associated with the activity of the atmosphere, hydrosphere and biosphere:

weathering (hypergenesis);

Geological activity wind;

Geological activity of flowing waters;

Geological activity of groundwater;

Geological activity of snow, ice, permafrost;

Geological activity of the seas, lakes, swamps;

Geological activity of man.

Endogenous processes create irregularities in the Earth's surface. The largest of them are created by tectonic movements. With downward movements (lowering) of sections of the earth's crust, depressions of large lakes, seas, and oceans arise. With the upward movements (uplift) of individual sections of the earth's crust, mountain uplifts, mountainous countries and entire continents arise.

Exogenous processes destroy the elevated areas of the earth's surface and tend to fill the resulting depressions. Thus, the relief of the Earth is an arena of a never-ending struggle between endogenous and exogenous forces, and the manifestation, confrontation of these forces is impossible without each other. Such an inseparable connection is called dialectical.

Denudation and penepelnization

Denudation is the process of destruction of rocks on the surface of the Earth, accompanied by the removal of the destroyed mass. Naturally, denudation leads to a lowering of the raised areas of the relief (Figure 4).

Figure 4 - Scheme of lowering the relief in the process of denudation: 1 - initial surface, 2 - surface after denudation

As a result of denudation, all new portions of rocks, previously covered from the impact of overlying masses, are exposed to exogenous processes and destruction.

In limited areas, denudation occurs most often as a result of the activity of any of the external factors: river erosion, marine abrasion, etc. Vast spaces are lowered under the combined influence of many external geodynamic processes. The denudation of mountainous countries proceeds the faster, the higher they are, and can reach a speed of 5-6 cm per year for the highest ranges (Caucasus, Alps). On the plains, the rate of denudation is much lower (fractions of millimeters per year), and in some places it is replaced by the accumulation of precipitation. Approximate calculations show that mountainous countries gradually decrease when denudation overcomes tectonic uplift, and in their place hilly plains - peneplens, as they are commonly called, can appear, and the time required for this is from 20 to 50 million years. The same calculations show that for the complete destruction of the continents, assuming the termination of the action of tectonic forces, it will take 200-250 million years. Continents can collapse to the level of ocean waters. Below this level, denudation processes practically stop: the ocean level is taken as the denudation limit.

Independent - local - levels of denudation can exist on the continents, as a rule, this is the level of large drainless depressions (Caspian, Aral, Dead Sea).

Plutonism and volcanism

Magmatism is the phenomenon associated with the formation, change in composition and movement of magma from the bowels of the Earth to its surface.

Magma is a natural high-temperature melt, formed as separate chambers in the lithosphere and upper mantle (mainly in the asthenosphere). The main reason for the melting of matter and the emergence of magma chambers in the lithosphere is an increase in temperature. The rise of magma and its breakthrough into the overlying horizons occur as a result of the so-called density inversion, in which foci of a less dense, but mobile melt appear inside the lithosphere. Thus, magmatism is a deep process caused by the thermal and gravitational fields of the Earth.

Depending on the nature of the movement of magma, magmatism is distinguished as intrusive and effusive. During intrusive magmatism (plutonism), magma does not reach the earth's surface, but actively intrudes into the enclosing overlying rocks, partially melting them, and solidifies in cracks and cavities of the crust. With effusive magmatism (volcanism), magma reaches the Earth's surface through a supply channel, where it forms volcanoes. various types and solidifies on the surface. In both cases, when the melt solidifies, igneous rocks are formed. The temperatures of magmatic melts located inside the earth's crust, judging by the experimental data and the results of studying the mineral composition of igneous rocks, are in the range of 700-1100°C. The measured temperatures of magmas erupted on the surface, in most cases, fluctuate in the range of 900-1100°C, occasionally reaching 1350°C. The higher temperature of terrestrial melts is due to the fact that they undergo oxidation processes under the influence of atmospheric oxygen.

In terms of chemical composition, magma is a complex multicomponent system formed mainly by silica SiO2 and substances chemically equivalent to silicates of Al, Na, K, Ca. The predominant component of magma is silica. In nature, there are several types of magmas that differ in chemical composition. The composition of magmas depends on the composition of the material, due to the melting of which they are formed. However, during the rise of magma, partial melting and dissolution of the host rocks of the earth's crust, or their assimilation occurs; while its primary composition changes. Thus, the composition of magmas changes in the course of both their intrusion into the upper horizons of the crust and crystallization. At great depths, magmas in the dissolved state contain volatile components - water vapor and gases (H2S, H2, CO2, HCl, etc.). high pressures their content can reach 12%. They are chemically very active, mobile substances and are retained in magma only due to high external pressure.

In the process of magma rising to the surface, as temperatures and pressures decrease, the system breaks up into two phases - melt and gases. If the movement of magma is slow, its crystallization begins in the process of ascent, and then it turns into a three-phase system: gases, melt and mineral crystals floating in it. Further cooling of the magma leads to the transition of the entire melt into a solid phase and to the formation of igneous rock. In this case, volatile components are released, the main part of which is removed along the cracks surrounding the magma chamber, or directly into the atmosphere in the event of an outpouring of magma on the surface. In the hardened rock, only an insignificant part of the gas phase is preserved in the form of tiny inclusions in mineral grains. Thus, the composition of the original magma determines the composition of the main, rock-forming minerals of the formed rock, but is not strictly identical to it in terms of the content of volatile components.

Endogenous disorders of the human psyche are a fairly common phenomenon today. For a number of factors, both adults and children can be exposed to this disease. Therefore, the issue of this disease is relevant and requires our close attention.

In world history there are sad examples of people falling ill with the strongest psychopathic ailments. Because of this "ailment" in the first centuries of our era, died great amount people, entire civilizations disappeared. In those days, the reason for this was the loss of people's trust in the authorities, the change of ideologies, religious views and beliefs. People, not wanting to live, committed suicide, women had abortions, abandoned their children, generally stopped creating families. In science, it's intentional, hate-related extinction. own life, was called "endogenous psychosis of the 2nd-3rd centuries." It was a mass psychogenic pathology in people who had lost the meaning of life.

A similar situation developed in Byzantium before the collapse. The Byzantine people, after the conclusion of the union, felt the betrayal of their faith, their worldview on the part of the authorities. People in Byzantium at this time succumbed to mass pessimism. The men became chronic alcoholics. A terrible depopulation began. In Byzantium at the end of the 14th century, only 25 out of 150 well-known intellectuals and intellectuals created their own families.

All this led in Byzantium to a serious destruction of the normal mental state of people, which brought great empire to your sunset.

Psychoses. Their types

Psychosis is a clear disorder of the mental state and mental activity of a person, which is accompanied by the appearance of hallucinations, changes in consciousness, inappropriate behavior, disorganization of the personality.

There are many types of psychotic illnesses. Their classification according to such a feature as origin is based on two types: endogenous and exogenous species.

Endogenous disorders of consciousness are caused by factors of internal influence: somatic or mental illness, age-related pathologies. Such deviations in the psyche develop gradually. The reason for exogenous deviations from the normal consciousness of a person are external factors: mental trauma received as a result of a negative impact on a person stressful situations, the transfer of infectious diseases, serious intoxication. Exogenous psychosis today very often becomes a consequence of chronic alcoholism.

Exogenous psychoses are considered the main source of the acute form of a psychopathic illness, which forms suddenly and very rapidly.

In addition to acute exogenous mental disorders, there are acute endogenous psychoses and acute organic (disorders of brain activity, consisting in damage to brain cells due to injuries or tumors) psychotic abnormalities. Their distinguishing feature consists in a sudden and very rapid development. They are temporary, not chronic. Also, a person with impaired consciousness in an acute form may experience relapses. Acute endogenous psychoses and other acute forms respond well to treatment, it is only important to diagnose psychosis in time and start treating it immediately. Timely therapy, first of all, is necessary due to the fact that with a deviation over time, the adequacy of a person and his ability to control the situation are increasingly reduced, this can lead to the appearance of processes that are already irreversible for the psyche.

endogenous psychosis. Causes, symptoms

Endogenous psychosis is a pathology of human consciousness, in which the patient experiences irritability, nervousness, delusional states and hallucinations, memory problems caused by internal processes occurring in the human body.

These forms include:

• paranoia;
• schizophrenia;
• Genuine epilepsy;
• affective states, etc.

Determine the causes of this disorder in each specific person hard. They may be:

• somatic (bodily) diseases: cardiovascular, nervous, respiratory, endocrine systems and etc.;
• genetic predisposition;
• another mental disorder (for example, Alzheimer's disease - the death of brain neurons, oligophrenia);
• age changes.

In this case, the patient can observe the following symptoms:

• irritability;
• excessive sensitivity;
• loss of appetite and sleep disturbances;
• decreased efficiency, ability to concentrate;
• feeling of anxiety and fear;
• rave;
• disruptions in thinking, hallucinations;
• deep depression;
• inability to control their behavior.

Mental pathology caused by internal factors in children and adolescents

The close attention of parents and mandatory treatment from specialists require mental disorders in children and adolescents.

Psychosis in children may be accompanied by the appearance of illusions, strange behavior, unreasonable aggressiveness. A child with a disorder caused by internal factors often composes some incomprehensible words. He may have a delusional state, hallucinations may appear.

The sources of deviations here are very different. The main ones are taking medications for a long time, hormonal imbalance, high temperature.

Quite often in our time there are psychotic disorders in adolescents. However, it can be difficult for parents and even doctors to determine any deviations in a person at this age due to complex adolescent behavior. Therefore, if a pathology is suspected, it is necessary to contact a narrow-profile specialist.

Modern statistics say that approximately 15% of adolescents need the help of a psychiatrist, 2% of young people are diagnosed with a psychotic disorder.

Symptoms of endogenous psychosis in adolescents differ little from the signs of the course of the disease in adults. But it is necessary to take into account the not fully formed teenage psyche, changes in the hormonal system. Pathological processes against the background of processes occurring with a person in adolescence can lead to the most sad consequences, up to the commission of suicide by a teenager.

Diagnosis and treatment of endogenous psychosis

Symptoms different types psychotic disorders are quite similar. In this regard, only a specialist (psychiatrist) after a thorough examination can determine the type of pathology in a patient caused precisely by factors of internal influence. Already at the first suspicious signs of a deviation in a person, first of all, his relatives and relatives, it is necessary to urgently consult a doctor and consult with him. The patient himself may not understand his condition. Self-treatment of endogenous psychosis is dangerous not only for health, but also for the life of the patient.

With the manifestation of an acute pathological form in a person, it is necessary for him to call an ambulance.

When confirming the diagnosis, the doctor prescribes a list of medicines to the patient. Typically, the following apply medications:

• sedatives (soothing);
• antidepressants (fighting depression and feelings of depression);
• tranquilizers (removing nervous tension, fatigue, relieving anxiety and fear), etc.

In addition to drug therapy, psychotherapy is also important. For each patient, individual techniques are used to cure him. For the successful recovery of the patient, it is important for the doctor to choose right ways therapy.

The duration of treatment for endogenous or exogenous psychosis may vary. It directly depends on at what stage of the course of the pathology the patient asked for help, how severely the disease is started. Subject to timely provision medical care healing can last for about two months. In a neglected case, the recovery process can stretch for a long, indefinite period.

Diagnosis and treatment of endogenous psychosis in the younger generation is not the same as in adults. When the first symptoms occur, the baby is examined by a number of specialists: a psychiatrist, an otolaryngologist, a neuropathologist, a speech therapist, and a psychologist. Diagnosis consists in a complete examination of the health of the little man, his mental, physical, speech development, doctors check his hearing, the level of development of thinking. For an even more detailed examination, the baby can be placed in a hospital. It happens that the roots of deviations in the psyche come from some other serious illness. In this regard, it is important not only to determine the child's psychogenic disorder, but also to identify the causes of the development of this disease.

Ways to cure small patients are different. Some children can recover after a few sessions with specialists, others need a fairly long observation. Most often, a child is prescribed psychotherapy, but sometimes only this method of dealing with endogenous psychosis is not enough. Then drugs are used. However, potent agents are used extremely rarely.

A special relationship and constant monitoring by a psychotherapist is required by representatives of a younger age, in whom endogenous psychosis has developed against the background of severe stressful situations.

In the modern world, children's mental illnesses (including endogenous and exogenous psychoses) are successfully treated. Relapses in later life are minimized if young children and adolescents receive timely help from specialists, of course, provided that there are no severe psychological shocks.

Huge responsibility falls on the shoulders of relatives and friends of sick kids. Parents must comply with the medication regimen, proper nutrition, spend a lot of time with their child on fresh air. It is very important that relatives do not treat the “flower of life” as an unbalanced person. The key to a speedy recovery of children is the unquestioning faith of parents in victory over the disease.

Endogenous psychoses are not uncommon today. However, do not despair if you close person or your offspring was diagnosed with this. Psychotic disorders are successfully treated! It is only necessary to consult a doctor in time, follow the treatment and believe in recovery. Then the person will be able to live a full life again.

ENDOGENIC PROCESSES (a. endogenous processes; n. endogene Vorgange; ph. processus endogenes, processus endogeniques; and. procesos endogenos) - geological processes associated with energy arising in the Earth. Endogenous processes include tectonic movements of the earth's crust, magmatism, metamorphism,. The main sources of energy for endogenous processes are heat and the redistribution of material in the Earth's interior in terms of density (gravitational differentiation).

The deep heat of the Earth, according to most scientists, is predominantly of radioactive origin. A certain amount of heat is also released during gravitational differentiation. The continuous generation of heat in the bowels of the Earth leads to the formation of its flow to the surface (heat flow). At some depths in the bowels of the Earth, with a favorable combination of material composition, temperature, and pressure, foci and layers of partial melting may arise. Such a layer in the upper mantle is the asthenosphere, the main source of magma formation; convection currents can arise in it, which serve as a presumed cause of vertical and horizontal movements in the lithosphere. Convection also occurs on the scale of the entire mantle, possibly separately in the lower and upper mantle, in one way or another leading to large horizontal displacements of lithospheric plates. The cooling of the latter leads to vertical subsidence (see). In the zones of volcanic belts of island arcs and continental margins, the main chambers of magmas in the mantle are associated with superdeep inclined faults (seismic focal zones of Wadati-Zavaritsky-Benioff), extending under them from the ocean (approximately to a depth of 700 km). Under the influence of a heat flow or directly from the heat brought by rising deep magma, the so-called crustal magma chambers arise in the earth's crust itself; reaching the near-surface parts of the crust, magma intrudes into them in the form of intrusions of various shapes (plutons) or pours out to the surface, forming volcanoes.

Gravitational differentiation led to the stratification of the Earth into geospheres of different densities. On the surface of the Earth, it also manifests itself in the form of tectonic movements, which, in turn, lead to tectonic deformations of the rocks of the earth's crust and upper mantle; the accumulation and subsequent discharge of tectonic stresses along active faults lead to earthquakes.

Both types of deep processes are closely related: radioactive heat, by lowering the viscosity of the material, promotes its differentiation, and the latter accelerates the removal of heat to the surface. It is assumed that the combination of these processes leads to uneven transport of heat and light matter to the surface in time, which, in turn, can explain the presence of tectonomagmatic cycles in the history of the earth's crust. Spatial irregularities of the same deep processes are involved in explaining the division of the earth's crust into more or less geologically active regions, for example, into geosynclines and platforms. Endogenous processes are associated with the formation of the Earth's relief and the formation of many of the most important