Types of weathering

It refers to exogenous (external) forces that affect. Weathering is of different types:

A kind of physical is frosty weathering, which is also characteristic of subarctic climatic zones... Here water freezes not only in cracks, but also in capillaries, tearing apart the rock to a loose state.

Chemical weathering... This is the destruction of rocks when they interact with chemically active elements (oxygen, carbon dioxide, organic acids). This type of weathering is especially noticeable in rocks containing iron - they are covered with a brown crust. Main areas the globe where a similar process takes place, are tropical latitudes. Here, rocks are destroyed by rainwater with chemically active elements dissolved in it.

This type of weathering is characterized by the accumulation in lakes and: bauxite, phosphorite, cobalt, sedimentary iron.

Organic bleaching... It proceeds under the influence of living organisms, which crush rocks with plant roots and acid during the decomposition of plant and animal residues. Animals, making passages and holes in, loosen it. Some marine molluscs drill holes in the rugged coastal cliffs. Mosses and lichens produce acids that dissolve rocks. The main result of organic weathering is the formation of soils.

The rock mass, which has undergone destruction, forms the weathering crust - a loose layer that forms in the zone of water seepage. In hot weather and where conditions are most favorable for its formation, the weathering crust reaches 100-200 m and more, although its thickness is usually 30-60 m. Depending on, not only the thickness of the weathering crust is different, but also its composition.

Invisible, inconspicuous forces of weathering, working from day to day, destroy rocks, near which large and small debris from boulders to sand accumulates. They roll, slide, slide along the slope, forming talus. They are usually shaped like a cone leaning against a slope. Gradually the talus grows in width and height, joins the neighboring ones, forming a trail of talus. The mountains seem to "sink" in heaps of rubble. The talus are formed more often in spring, when the snow melts, or in a quiet frosty one.

Weathering- a set of processes of physical and chemical destruction of rocks and their constituent minerals at the place of their occurrence: under the influence of temperature fluctuations, freezing cycles and chemical effects of water, atmospheric gases and organisms.

Weathering occurs due to the combined effect of the agents (factors) of weathering from the hydrosphere, atmosphere and biosphere on the upper shell of the lithosphere. As a result, a weathering crust and weathering products are formed. Weathering can penetrate to a depth of 500 meters.

"Death Mountain" near the Cornish Park in Serovo in St. Petersburg

Weathering types

There are several types of weathering, which can prevail to varying degrees:

Physical or mechanical (friction, ice, water and wind);

Chemical;

Biological (organic);

Radiation (ionizing).

Physical

The greater the temperature difference during the day, the faster the weathering process takes place. The next step in mechanical weathering is the ingress of water into the cracks, which, when frozen, increases in volume by 1/10 of its volume, which contributes to even greater weathering of the rock.


"Arch" in Utah (USA), an example of mechanical weathering

If blocks of rocks fall, for example, into a river, then there they are slowly grinded and crushed under the influence of the current. Mudflows, wind, gravity, earthquakes, volcanic eruptions also contribute to the physical weathering of rocks. Mechanical crushing of rocks leads to the transmission and retention of water and air by the rock, as well as a significant increase in surface area, which creates favorable conditions for chemical weathering. As a result of cataclysms, rocks can crumble from the surface, forming plutonic rocks. All the pressure on them is exerted by the lateral rocks, because of which the plutonic rocks begin to expand, which leads to the disintegration of the upper layer of the rocks.

Chemical

Chemical weathering is a combination of various chemical processes that result in further destruction of rocks and a qualitative change in them. chemical composition with the formation of new minerals and compounds.


Rocks near Lake Kolyvan, Altai Territory

The most important factors chemical weathering are water, carbon dioxide and oxygen. Water is an energetic solvent for rocks and minerals. The main chemical reaction of water with minerals of igneous rocks is hydrolysis, which leads to the replacement of cations of alkaline and alkaline earth elements of the crystal lattice with hydrogen ions of dissociated water molecules.

The resulting base (KOH) creates an alkaline environment in the solution, in which further destruction of the crystal lattice of orthoclase occurs. In the presence of carbon dioxide, KOH transforms into the form of carbonate.

The interaction of water with minerals of rocks also leads to hydration - the attachment of water particles to mineral particles.

In the zone of chemical weathering, the oxidation reaction is also widespread, to which many minerals containing oxidizable metals are subjected. A striking example of oxidative reactions during chemical weathering is the interaction of molecular oxygen with sulfides in aquatic environment... Thus, during the oxidation of pyrite, along with sulfates and hydrates of iron oxides, sulfuric acid is formed, which participates in the creation of new minerals.

Biological

Biological weathering is produced by living organisms (bacteria, fungi, viruses, burrowing animals, lower and higher plants) .In the course of their life, they act on rocks mechanically (destruction and crushing of rocks by growing plant roots, while walking, digging holes by animals). Microorganisms play a particularly important role in biological weathering.

Radiation

Radiation weathering is the destruction of rocks under the influence of radiation, or solar radiation... Radiation weathering affects the processes of chemical, biological and physical weathering. A typical example of a rock subject to radiation weathering is regolith on the moon.

Regolith(from ancient Greek ῥῆγος - blanket and ancient Greek λίθος - stone) - residual soil, which is a product of rock weathering in place.

Currently, this term is most often called the surface layer of loose lunar soil.

B. Aldrin's boot trace on regolith (Apollo 11)


Lunar soil delivered by the Apollo 11 crew (a gift to the USSR from the USA), Museum of Cosmonautics

Term regolith was first used by the American geologist G.P. Merrill in 1897. He gave him this definition:

Regolith - all surface loose formations representing the upper layers of the earth's surface: humus soils, alluvium, weathering products, such as laterite, aeolian deposits, slope debris, glacial deposits, etc.

Modern term regolith most often applied in relation to lunar soil, as:

Unconsolidated product of crushing and redeposition of lunar rocks, covering the surface of the Moon in a continuous cover. Regolith consists of fragments of lunar rocks and minerals ranging in size from dust particles up to several meters in diameter, glass, lithified breccias, fragments of meteorites, etc.

The term also applies to materials covering the surfaces of other small atmospheric planets and satellites (for example, Mercury, Deimos), as well as asteroids. Regolith occurs as a result of crushing, mixing and sintering of lunar rocks during the fall of meteorites and micrometeorites under vacuum and unabated cosmic radiation.

By radioisotopes found that some debris on the surface of the regolith had been in the same place for tens and hundreds of millions of years.

Lunar regolith composition

Non-layered, loose, uneven-grained clastic-dusty layer, reaching a thickness of several tens of meters. It consists of fragments of igneous rocks, minerals, glass, meteorites and breccias of shock-explosive origin, cemented by glass.

In terms of granulometric composition, it belongs to silty sands (the bulk of the particles have a size of 0.03-1 mm). The color is dark gray to black with inclusions of large particles with a mirror-like sheen. Soil particles have high adhesion due to the absence of an oxide film on their surface and high electrification. In addition, lunar dust easily rises upward from impacts and adheres well to the surface of solids, which caused a lot of inconvenience to the members of the Apollo expeditions. According to Armstrong, Aldrin and Professor W.F. Scott in earthly atmosphere regolith has a characteristic smell of burning and shot caps.

Alexander Pavlovich Vinogradov(August 9 (21), 1895 - November 16, 1975) - Soviet geochemist, organizer and director of the Institute of Geochemistry and Analytical Chemistry (GEOKHI) of the USSR Academy of Sciences, founder and head of the first domestic department of geochemistry (at Moscow State University), vice president, academician of the USSR Academy of Sciences. Foreign member of the Bulgarian Academy of Sciences (1974).

A.P. Vinogradov distinguishes two types of particles in the regolith: angular, similar to freshly crushed rock, and predominant rounded particles with traces of fusion and sintering. Many of them are vitrified and look like glass and metal drops. According to the mineral composition of the regolith, it has been established that the lunar seas are composed mainly of basalts, while anorthosites and their varieties prevail among the rocks of the continents. Regolith of both types is characterized by the presence of metallic iron particles.


Samples of lunar regolith (Khabarovsk Regional Museum named after N.I. Grodekov)

Delivery of regolith from the Moon

The first instrumental determination of the density and strength of the surface layer of the regolith was carried out by the Soviet automatic station "Luna-13" on December 24-31, 1966.

For the first time, lunar soil was delivered to Earth by the crew of the Apollo 11 spacecraft in July 1969 in the amount of 21.7 kg. During the lunar missions under the Apollo program, a total of 382 kg of lunar soil were delivered to Earth.


Regolith under the wheels of the Lunar Car

The automatic station "Luna-16" delivered 101 g of soil on September 24, 1970 (after the Apollo-11 and Apollo-12 expeditions).

"Luna-16", "Luna-20" and "Luna-24" delivered soil from three regions of the Moon: the Sea of ​​Abundance, the mainland region near the crater Amegino and the Sea of ​​Crises in the amount of 324, and it was transferred to the GEOKHI RAS for research and storage.

China's lunar program plans to deliver up to 2 kg of regolith by the Chang'e-5 spacecraft in 2017.

Weathering products

Weathering products in a number of areas of the Earth on the day's surface are kurums. Weathering products under certain conditions are crushed stone, grit, "slate" fragments, sandy and clay fractions, including kaolin, loess, individual fragments of rocks of various shapes and sizes, depending on the petrographic composition, time and weathering conditions.

Kuruma

Kurums (Ancient Türkic gorum - "stony placers", "piles of sharp stones", "fragments of rocks") is a term used by physical geography, geology and geomorphology; has two meanings:

Local, limited in three-dimensional space, accumulations of stone acute-angled blocks, formed in a natural way, having the appearance of a closed undivided cover on the daytime surface of the earth;

The type of the earth's surface of a complex structure, - kurumland,- which is a closed group of large stone blocks with sharp broken edges, located on an undivided underlying surface of various slopes and having the ability to move. It has its own microclimate, hydrology, flora and fauna.

The leading scientific center for the study of Kurums in Russian Federation is Moscow State University named after M.V. Lomonosov.


Vitosha (bulgarian Vitosha) - mountain range in Bulgaria



Vitosha

The term is widespread in many areas of Asia. Firmly entrenched in the world geographical literature and cartography in the name of the mountain system Karakorum or Karakurum, which means from the ancient Turkic "black stone, black rock".


K2 (Baltoro Muztag, Central Karakorum, Pakistan)


In scientific circulation in Russian, the term kurum to designate extensive coarse-grained stone placers was introduced by the Russian geologist Ya. A. Makerov in his monograph "Upland terraces of Siberia and their origin" (1913). The term is firmly established in a number of other languages. However, in the Russian scientific literature, a large number of synonyms for the word "kurum" are used - "rocky talus", "stone placer", "stone trail", "debris accumulation", "block placer", "kurum field", "stone river", " stone sea ”,“ stone glacier ”,“ moving stream of rubble ”,“ kurumnik ”,“ breakdown of stone blocks ”. The Russian researcher AF Glazovsky cites information that in a number of mountainous regions of Altai and Sayan, this natural phenomenon is called "uterus".


Kurumnik in the Urals


Stone River in the Falkland Islands

Distinctive features of kurum: these are usually large blocks - statistically the size has not yet been determined, but usually from several cm in a small diameter to 1-2 m, having the appearance of freshly broken, but never rounded, in motion when colliding with each other and friction against the underlying surface can acquire very slight roundness, close with each other, forming groups in quantities ranging from a few blocks to tens of thousands or more. Kurum can occupy an area from units of m2 in projection onto the underlying surface to colossal "fields" or " stone seas". In some regions of the Earth, kurums completely cover the entire area with a stone cover, forming a kind of so-called "day surface" that is unlike anything else.

Kurums must be distinguished from crushed stone and grit placers, which are composed of fine detrital material - crushed stone and grit.

Kurums are formed where hard rocks come out on the surface of the day. Most often these are mountainous regions or plateaus of all continents. Kurums are usually formed during the destruction of various types of limestones, crystalline shales, granites, gneisses, basalts, dolerites, sandstones, quartzites, amphibolites, diabases, porphyrites, vitroclastic tuffs.

One of the first to point out the genesis or origin of the Kurums was the Russian military geographer of Belarusian origin NM Przhevalsky; he believed that kurums are formed as a result of the destruction of rocky rocks due to uneven heating and cooling where the amplitude of day and night temperatures is large. It is also obvious that kurum formation is more intense in spring and autumn for the same reasons. Perhaps cracking of rocks can occur when cold rain is poured onto the heated surface of the rocks.

There are several natural areas formations of kurums, all of which have a harsh nival climate: the Arctic, Antarctic and adjacent polar and subpolar regions, subnival and nival or "cold" belt of mountains, zones of winter anticyclones. So, in the zone of the winter Siberian anticyclone, usually from the middle of autumn, the whole winter and part of spring is clear sunny weather with the lowest surface air temperatures in the Northern Hemisphere of the Earth. This is an area of ​​widespread distribution of curums, which indicates the frosty weathering of rocks that protrude onto the day's surface.

The spread of kurums over the surface of the Earth is extremely uneven. There are areas where kurums are the predominant type of the earth's surface, in other places they are only "spots" in the relief, somewhere kurums are not found at all, and this is a mystery of modern geomorphology. The origin or genesis of kurums, and hence the geography of their distribution, is obviously a consequence of a large number of different factors: lithology, climate, exposure of slopes, absolute height terrain and others. Thus, in the Tien Shan and Gissar-Alai, kurums are not the predominant type of surface; in the Vitim river basin, kurums occupy extremely large areas.


Swietokrzyskie Mountains, Poland

Mallorca

The question of the origin or genesis of kurums is a subject of scientific debate, and the opinions of researchers differ. According to existing data, kurums in general can be attributed to three groups:

Relic kurums left in relief from past eras;

- "young" kurums, formed in the era of the last continental glaciations;

Kurums currently being formed.

The initial material for the formation of stone detachments or blocks is originally undivided "parent" rocks. The place where the kurums are formed is sometimes called the “feeding area” of the kurums. Over time, the kurum can grow, increasing in size, move along the underlying surface and occupy an ever larger area. The advancing leading edge of the moving mass of closed coarse-grained boulders is called the “front of the kurum”, its lateral margins are called “flanks”, and the area where the kurum originates and from where it began its movement is called the “rear of the kurum”. There are usually no curums on the flat tops of the mountains, but their slopes are often abundantly covered with a continuous layer of large stone fragments.

A number of observations show that kurums, buried earlier in the thickness of loose sediments, can reappear on the surface for various reasons.

Kurums can supply detrital stone material for moraines of various genesis, mudflows, slope taluses, form rapids in rivers and streams, or generally block their channels. The presence of kurums, their ability to move must be taken into account in the construction of various structures. Therefore, kurums and their properties are studied by engineering geology and geomorphology.

V general view the process of kurum formation and the movement of stone masses of kurums down the slope leads to a leveling of the relief and a decrease in its absolute height. Kurums are a product of destruction of the "parent" rocks, which is the process of destruction of mountain masses and leads to denudation of the relief.

Inattentive researchers sometimes confuse kurums with moraines of various origins, wasps, stopped mudslides, talus and other forms of debris and other covers composed of stone detachments. Sometimes kurums form extended bands on mountain slopes when the width of such a "stream" is less than its length, and then such formations are called "stone rivers". The depth or thickness of the lump cover is different, but not too great. Crushed stone, gruss and other small debris are usually destroyed, washed away by water down the slope, exposing voids between the boulders. For small animals, kurums provide refuge from larger predators. It is extremely difficult for large animals, horses and humans to move on the surface of the kurum, and sometimes it is simply impossible.

Observations and experiments show that many kurums move, usually down the slopes of the mountains. Sometimes it is a slow movement, sometimes - catastrophically fast, as, for example, during an earthquake. Cases of movement of kurums with a terrible roar in winter in the mountains of the north are described Eastern Siberia... In their movement, kurums can cut off the soil cover, destroy vegetation, change the living conditions of animals, the hydrological regime and atmospheric processes in the surface layer.

The immobile kurum is called "dead" or "sleeping". Fixed kurum tends to be covered by various types of vegetation and is inhabited by certain species of animals, which the kurum provides the opportunity to arrange burrows and shelters, as well as naturally protected communication routes.

Kurum has its own microclimate, which is determined by its morphometry, location and the flora and fauna inhabiting it. According to the data of the Russian geomorphologist Yu. G. Simonov, in Eastern Siberia, the depth of penetration of daily temperatures into the "body" of the kurum is on average 0.4 m.

Sometimes kurums are completely covered with mosses and other vegetation, which completely disguises them. By virtue of their architectonics, kurums have their own very specific properties: thus, ice and firn can be preserved in the “body” of the kurum all year round; it is obvious that the sun's rays do not penetrate into the "thick" curum, it is not blown inside by warm winds and is a cold accumulator. Sometimes the kurums "armour" the underlying rocks and "spots" are formed under the kurums in the nival climate. permafrost... From the melting of snow and firn in the "body" of the kurum, temporary, and sometimes permanent, water flows that only change the volume of runoff depending on the time of day and year are formed, invisible from the surface, but clearly audible. Merging, such streams lower along the slopes of the mountains come to the surface of the day and form already real streams and even rivers that form their own channels. Kurums also in some regions have the ability to accumulate atmospheric moisture in their "body" and, to the surprise of travelers, you can find pools of water and streams even near the tops of the mountains. Until now, hydrogeologists have not been able to reliably take into account the water balance taking into account the "kurum" waters. In Buryatia and the Chita region, according to the Russian hydrogeologist N.A.Velmina, up to 20% of groundwater is formed due to the condensation of atmospheric moisture in the curums. This feature of the covers, composed of detrital rocks, has been used by the civilizations of Asia since ancient times. So, in some areas, creating an artificial cover of rock debris around trees, a person completely satisfied the plant with the necessary moisture and watering was not required! This agrotechnical technique was widely used by the inhabitants of the Crimea. There is also an amazing way to "create" artificial streams in desert areas, namely: an extended trench is made on an inclined rocky or clay surface and, then, pyramids of stones are folded along its entire length; atmospheric moisture passes from a gaseous to a liquid state on the surface of the stone, flows down and forms a real stream of fresh water.

Kurums, without using the real term, were described by many geographers and travelers of all times and peoples. One of the first kurums on the slope of the Munku-Sardyk mountain range in the Eastern Sayan mountains was marked by a special sign on his map by the Russian geologist and geographer SP Peretolchin in his monograph "Glaciers of the Munku-Sardyk Ridge".Since the XX century in Russian topographic maps and other engineering and geological documentation, the kurums are marked with a special conventional sign.

Regions of widespread distribution

Byrranga


The approximate location of the Byrranga mountains on the Taimyr Peninsula





Sayan



Western Sayan, Ergaki ridge. Hanging stone in the western part of Ergak

Ural

Stone rivers of the Urals



Wrangel Island


Wrangel Island - Location Map


Color photograph of Wrangel Island taken from space in 2001


Wrangel Island - image from space


Mountains on Wrangel Island


In the mountains on Wrangel Island


Stan highlands





Falkland Islands



Satellite image of the archipelago


Erosion

Erosion (from lat. erosio- erosion) - destruction of rocks and soils by surface water flows and wind, including the separation and removal of material debris and accompanied by their deposition.

Often, especially in foreign literature, erosion is understood as any destructive activity of geological forces, such as the surf, glaciers, gravity; in this case, erosion is synonymous with denudation. For them, however, there are also special terms: abrasion ( wave erosion), exaration ( glacial erosion), gravitational processes, solifluction, etc. The same term (deflation) is used in parallel with the concept wind erosion but the latter is much more common.

According to the rate of development, erosion is divided into normal and accelerated... Normal always takes place in the presence of any pronounced runoff, proceeds more slowly than soil formation and does not lead to a noticeable change in the level and shape of the earth's surface. Accelerated is faster than soil formation, leads to soil degradation and is accompanied by a noticeable change in relief.

For reasons distinguish natural and anthropogenic erosion. It should be noted that anthropogenic erosion is not always accelerated, and vice versa.


Erosion in Antelope Canyon, Southwest USA


Wind erosion of soil, about. Hawaii

Wind erosion

This is the destructive effect of the wind: waving of sands, forests, plowed soils; the occurrence of dust storms; grinding rocks, stones, structures and mechanisms with hard particles carried by the force of the wind. Wind erosion is classified into two types:

Casual

Dust storms

The beginning of a dust storm is associated with certain wind speeds, however, due to the fact that the flying particles cause a chain reaction of the detachment of new particles, its end occurs at significantly lower speeds.


Wind-eroded gneiss boulder (Nanshan Mountains, China)

The strongest storms took place in the USA in the 1930s ("Dust Cauldron") and in the USSR in the 1960s, after the development of virgin lands. Most often, dust storms are associated with irrational human economic activities, namely, massive plowing of land without carrying out soil protection measures.

There are also specific deflationary landforms, the so-called " blowing basins»: Negative forms, elongated in the direction of the prevailing winds.

Water erosion

Wheat Gullies, USA

Water erosion occurs under the influence of temporary streams of atmospheric water (heavy rains, melt water, etc.).

Drip erosion

Destruction of the soil by the blows of raindrops. Structural elements(lumps) of soil are destroyed by the kinetic energy of raindrops and are scattered to the sides. On slopes, the downward movement occurs a greater distance. Falling, soil particles fall on a film of water, which contributes to their further movement. This type of water erosion is of particular importance in the humid tropics and subtropics..

Plane erosion

Planar (surface) erosion is understood as a uniform washout of material from the slopes, leading to their flattening. With some degree of abstraction, they imagine that this process is carried out by a continuous moving layer of water, but in reality it is produced by a network of small temporary water streams.

Surface erosion leads to the formation of washed away and reclaimed soils, and in more large scale- deluvial deposits.

Linear erosion

Unlike surface erosion, linear erosion occurs on small areas of the surface and leads to the dismemberment of the earth's surface and the formation of various erosional forms (gullies, ravines, gullies, valleys). This also includes river erosion, produced by constant flows of water.

Washed material is usually deposited as fan cones and forms proluvial deposits.

Linear erosion is of two types:

G lubin (bottom) - destruction of the bottom of the stream channel. Bottom erosion is directed from the mouth upstream and occurs until the bottom reaches the level of the base of erosion;

Lateral - the destruction of the coast.

In every permanent and temporary watercourse (river, ravine), you can always find both forms of erosion, but at the first stages of development, deep erosion prevails, and in subsequent stages - lateral.


An example of combined lateral and deep erosion. Sukhona coast

Erosion spread

Erosion processes are ubiquitous on Earth. Wind erosion prevails in an arid climate, water erosion in a humid climate.

Corrasia (lat. corrado- scraping, scraping) - the process of mechanical erosion, grinding, abrasion, grinding and drilling of rock masses by moving masses of detrital abrasive material moved by water, wind, ice or displaced by the force of gravity along the slopes. So, in deserts, corrosion occurs under the influence of sand, in the bed of a glacier - by boulders, in the river bed - by debris drawn by water. As a result, a cellular structure, furrows, hollows and other depressions are formed on the surface of the rocks.


Suffosia (from lat. suffosio- digging) - removal of small mineral particles of the rock by water filtering through it. The process is close to karst, but differs from it in that suffusion is predominantly a physical process and rock particles do not undergo further destruction. One of the characteristics of soil erosion.

Suffusion leads to subsidence of the overlying strata and the formation of depressions (suffusion funnels, saucers, depressions) up to 10 and even 100 meters in diameter, as well as caves. Another consequence may be a change in the granulometric composition of rocks, both susceptible to suffusion and being a filter for the material removed.


One of the outlandish landforms that complicates Uluru. There are many caves here, the genesis of which is not yet clear. Perhaps their formation is associated with suffosion or karst. Apparently, these processes took place here for millions (or tens of millions of years), which led to the formation of relief forms, which, rather, can be expected on a limestone plateau ...

Suffosia is most widely developed in the area of ​​distribution of loesses and loess-like loams, under the slopes of river valleys, often along the paths of burrowing animals. One of the necessary conditions for suffusion is the presence in the rock of both large particles that form an immobile frame, and washed out small ones. The removal begins only with certain values ​​of the water pressure, below which only filtration occurs.

In carbonate and gypsum-bearing sandy-argillaceous deposits and marls, karst and suffusion can occur simultaneously. This phenomenon is called clay karst or clayey pseudokarst.

Kigilyakhi (Yakut. kisilyakhi, kisi - man) - high rocky pillars of bizarre shape, formed as a result of cryogenic weathering. Stones sticking out on the surface of flat mountains or from under ice and snow resemble a person, which is where the name comes from.

Kigilyakhi. Stone giants and their secrets


Photo: meic / ykt.ru

There are many places on our planet, the origin of which cannot be fully explained by man. Around such objects, many legends and tales are born, explaining what is difficult to rationalize. Kigilyakhs, or kisilyakhs, are one of such objects. They are tall pillars formed from rocks, which are usually located on the tops of rocks during weathering. It is not surprising that tall pillars resembling frozen figures of giants have become heroes of many legends in Yakutia, where they are located.

HISTORY OF EDUCATION OF KIGILYAKH

The largest number of pillars-kigilyakhs is located in northern Yakutia, the most impressive stone figures are located on the Novosibirsk Islands, this is where most tourists come. It is interesting that from the Yakut “kisilyakh” it literally translates as “a place where there are people”, since the word “kis” itself is “a person”. It is known that the Yakut Kisilyakhs arose about 120 million years ago. Around this time, the Verkhoyansk and Chersky ridges were formed as a result of the collision of the North American continental plate with the Eurasian one. It was after the formation of folds on these ridges that the kigilyakhs began to form. True, they owe their origin to weathering, which, in frosty weather and location (tops of rocks), forms stone pillars. The material of which the kigilyakhs are composed are hard rocks, mainly granite.

There is another version of the origin of these rocks, it, as usual, is associated with otherworldly forces. Legend has it that once the earth was not yet covered with snow and permafrost, people then lived mainly in mountainous areas. But over time, the climate also changed, the dwelling in the rocks became unusable, as a strong cold snap began. At the moment when life became completely impossible, people decided to move to the south, descend from the mountains. But during the crossing of the Kisilyakh ridge, many of them, unable to withstand the cold, froze. Over time, they turned into stone pillars, which, being covered with more and more layers of stone, reached their present size.


Photo: meic / ykt.ru

LOCATION

Kigilyakhs are quite common all over the world, they are in Kazakhstan - the Koitas massif is known, there are mountain ranges in Transbaikalia. V different countries stone pillars are called differently, somewhere - "stone monks", due to the fact that they resemble frozen praying priests. In Russia, the most famous kigilyakhs are located in Yakutia, where tourists interested in magic stones come annually. The most famous places where the stones are found are the Kisilyakhsky ridge, Medvezhy and Lyakhovsky islands. In general, the very word "kigilyakh" began to be used by geologists all over the world relatively recently, this happened after the discovery of the Lyakhov Islands, when the Cape Kigilyakh and the peninsula of the same name were discovered and named. Two islands belonging to the Lyakhovsky group - Chetyrekhstolbovoy and Stolbovoy - are located mainly in the Laptev Sea. One more famous place"Habitat" of the Kigilyakhs is Mount Kisilyakh-Tas, it is located 100 kilometers from the coast East Siberian Sea, on the banks of the Alazeya River flowing through the tundra. It is on this mountain that the kigilyakhs form the so-called ridge, since the ridge of pillars stretches along the entire top of the mountain. It is also important to be able to distinguish kigilyakhs from nunataks (from the Eskimo “nuna” and “so”, which literally means “lonely peak”). These various stone pillars are very similar, nunataks are rocks that stand alone, or rocky peaks that form on the surface of a glacier. This is their main difference from the kigilyakhs - nunataks are formed not only as a result of weathering, their appearance is also influenced by rocks destroyed by the glacier. But if the ice disappears around and the nunatak remains on the bare rocky surface, you can hardly distinguish this stone pillar from the kigilakh. Perhaps only geologists can accurately determine the cause of the formation of stone pillars.


Photo: meic / ykt.ru

KISILYAKH RIDGE

Kisilyakhsky ridge is one of the most scenic spots habitat of the kigilyakhs, it is located on the watershed of the Adycha and Yana rivers. Besides, in mountain system Chersky, this ridge is one of the smallest. Its length is about 80 meters, and the highest peak reaches 1548 meters. The ridge consists of many different rocks, which allows us to consider it complex, it includes: clay shales, Jurassic sandstones, mudstones and other minerals, scientists believe that all these granitoids belong to the Cretaceous period. It is these sedimentary rocks that form the kigilyakhs, some of which can reach 30 meters in height. They are located on the main ridge of the ridge and, in addition, stretch along the entire watershed. It is interesting that it is on the Kisilyakhsky ridge that the kigilyakhs sometimes form impassable walls or labyrinths with small passages between the pillars. The lower the kigilah is, the lower it is, but at the same time ideally even pillars are located on the top, and below they acquire interesting and bizarre shapes. Kigilyaham are assigned the same strange names that tell you what the pillar looks like. In general, many tourists consider it their duty to name their favorite kigilyah in some unusual way. Therefore, if you read the travel notes of different travelers who have visited the same place, you will not find the same names for stone pillars. Each will give them names at their discretion, focusing on what the stone reminded him of. The Kisilyakhsky ridge is covered with many cracks and crevices, and its northern side is completely covered with lichens and mosses. Many researchers note another feature of the kigilyakhs - the presence of a leg. The famous geologist G. Mydel wrote in his research that the foot of the stone pillars is a base as tall as a person, while it is slightly thinner than the kigilah itself. At the same time, the exact age of the stones remains unknown: how many scientists, so many guesses.


Photo: Ayar Varlamov / yakutiaphoto.com

EXPEDITIONS TO STUDY KISILYAKH

Many scientists in different time made expeditions to the islands of Yakutia in order to find out the true origin of the kigilyakhs. So, in 1921-1923, F.P. Wrangel conducted an expedition, during which his group explored the Bear Islands, which are located in the East Siberian Sea. The group of these islands included the island of Chetyrekhstolbovoy, it was on this island that Wrangel first discovered the kigilyakhs, in his notes on the campaign he tried to find out their reasons for their formation. "We can conclude that three now separated stones once made up one large cliff: gradually cleaving and crumbling from the force of frost or other physical problems, it lost its primitive appearance," he wrote, first noting weathering as main factor the formation of new kigilyakhs.

And in 1935 on the same island from new expedition arrived geologist S. Obruchev, who also investigated the kigilyakhi. In his memoirs, he described not only the theory of the formation of stones, but also told the story of their discovery. According to him, the Bear Islands were discovered back in 1702 and were first visited in 1720. Another fact noted by him is interesting: the pillars collapsed very quickly. Obruchev wrote that if in 1720 there were four pillars, then in 1935 only three were found, and the fourth turned into a stone placer and lay at the foot of the rest. At the same time, the geologist notes that only 200 years are enough for all the kigilyakhs on Chetyrekhpolbovoy to be destroyed. But Obruchev's research was not taken seriously, as he made too many inaccuracies in his notes. So, in the same 1935, another expedition visited the island - the explorer Vorobyov, who discovered and described all four kigilyakhs. However on this moment It is known that the pillars located on the Kisilyakhsky ridge are covered with vertical cracks and therefore are rather unstable. But, despite the existing danger of collapse, locals kigilyakhs have been considered since ancient times the best place recreation. Sitting with them, according to legends, you can gain mental strength and tranquility. And in 1986, at the foot of the Kisilyakh ridge, archaeologists discovered more than 68 sites of ancient people and a burial. These findings indicate that the mountainous area of ​​Yakutia in ancient times was densely populated. And perhaps the locals are right, believing that the kigilyakhs carry the forces of ancient ancestors.


Photo: Ayar Varlamov / Yakutia

Weathering is understood as a set of physical, chemical and biochemical processes of transformation of rocks and their constituent minerals in the near-surface part. crust.

This transformation depends on a number of factors: temperature fluctuations, the chemical effect of water and gases - carbon dioxide and oxygen (found in the atmosphere and dissolved in water); the effects of organic substances formed during the life of plants and animals and during their dying off and decomposition. Those. weathering processes are closely related to the interaction of the near-surface part of the earth's crust with the atmosphere, hydrosphere, and biosphere. It is the boundary region of different phases that has high reactivity. The near-surface part of the earth's crust, in which the transformation of mineral matter occurs, is called the weathering zone.

The weathering process depends on the climate, relief, organic world and time.

PHYSICAL WEATHERING

In this type, temperature weathering is of little importance, which is associated with daily and seasonal temperature fluctuations, which causes either heating or cooling of the surface part of rocks.

Large differences in the coefficient "expansion - compression" of rock-forming minerals under prolonged exposure to temperature fluctuations leads to the fact that the cohesion of individual mineral grains is broken, cracks are formed, and then the rocks disintegrate into fragments (lumps, crushed stone, sand, etc.). The processes of physical weathering are very intensive in deserts, where there is little precipitation and high drops (daily) temperatures.

On mountain slopes, along with weathering, gravitational processes develop: landslides, rock falls, talus, landslides. The products of gravitational processes (talus, landslides) accumulated at the base of the slopes represent a kind of genetic type of continental sediments called colluvium.

In polar and subpolar countries, where there is permafrost and excessive surface moisture, weathering is done with the wedging action of freezing water in cracks. When the water freezes (the volume of ice is 9% higher than the frozen water), stress occurs in the cracks, the fragmentation of rocks and the formation of blocky material. This weathering is called frosty.

Roots of plants, especially trees, have a wedging effect on rocks. Various burrowing animals also perform mechanical work.

Purely physical weathering leads only to mechanical fragmentation of rocks without changing their mineral and chemical composition.

CHEMICAL WEATHERING

Simultaneously with physical weathering, there are processes of chemical weathering - chemical decomposition of rocks and the formation of new minerals.

With the mechanical destruction of rocks, cracks are formed in the latter, through which water and gases penetrate. The penetration of water causes the migration of various chemical compounds with it ..

Hydrolysis. Hydrolysis destroys the atomic structure of minerals, especially silicates, due to the action of water and ions dissolved in it. A water molecule has a polar structure: one end of it carries a weak positive charge due to two hydrogen atoms, and the other - negative due to an oxygen atom. Each end of the molecule can attach to an oppositely charged ion in the mineral's lattice and "rip" the latter out of the structure. In addition, water weakly dissociates into hydrogen ions (H +) and hydroxyl groups (OH -), which, upon dissociation, acquire freedom and can react with ions of the crystal structure. Natural waters usually contain dissolved ions of certain substances, especially HCO 3 -, SO 4 2-, Cl -, Mg 2+, Na +, K +. These ions can also replace charged atoms in the structure, thus disrupting the structure. the primary lattice of the mineral. Ca 2+, Mg 2+, Na + and K +

Hydration - under the influence of water, water molecules are fixed in the crystal structure of the mineral. In this case, new minerals are formed, for example, the transition of anhydrite to gypsum:

CaSO 4 + 2H 2 O → CaSO 4 ∙ 2H 2 O

Or the transition of goethite to hydrogoethite

FeOOH + nH 2 O → FeOH ∙ nH 2 O

Chlorite, talc, serpentine, zeolites, etc. are formed by hydration.

Carbonation. Minerals containing Ca, Mg, Na and K ions react with natural waters saturated with carbon dioxide. In this case, carbonates and bicarbonates of these minerals are formed. This process is called carbonation.

Dissolution. Many minerals are dissolved by the action of water flowing down the surface of rocks and seeping through cracks and pores to depth. The acceleration of the dissolution processes is facilitated by the high concentration of hydrogen ions, oxygen, carbon dioxide and organic acids.

Of the minerals, chlorides have the best solubility - halite, sylvin, etc. In second place are sulfates - anhydrite, gypsum. In third place are carbonates - limestones and dolomites. Due to the dissolution of these rocks, karst forms both on the surface and at depth.

Oxidation is the addition of oxygen to minerals, especially those that contain iron. Oxygen from air and water destroys sulfides and ferrous silicates such as olivine, pyroxenes and amphiboles, and converts ferrous iron to ferric:

Organic. Plants and animals help not only physical but also chemical weathering. Lichens, which are among the first to grow on a newly exposed rock, absorb some of the chemical compounds and "eat away" the breed. The roots of other plants remove new portions of inorganic material. The chemical activity of numerous and ubiquitous bacteria leads to the formation of ammonia, nitric acid, carbon dioxide, etc.

WEATHERING CRUST

The weathering crust is a loose surface layer of rocks formed as a result of weathering. The weathering crust also includes water, air and living organisms located in this layer. Usually the weathering crust has a clay composition. The thickness of the weathering crust depends on climatic conditions and from the duration of the weathering process, there are places where the weathering crust is absent. In the upper part, the weathering crust usually passes into the soil. Deposits of ores of nickel, iron, chromium, aluminum, phosphorus, rare elements, gold, etc. are associated with the ancient weathering crust.

Weathering products remaining at the site of destruction of the parent (bedrock) rocks are called eluvium.

The weathering crust is a collection of various eluvial formations. Such a residual weathering crust is called automorphic.

With prolonged weathering and appropriate conditions, well-defined zones of the weathering crust are formed, which have their own textural and structural features and mineral composition.

Due to the presence of oxides and hydroxides of Al and Fe, the eluvium of the upper part of the weathering crust in the dry state resembles fired brick, often forming shells and colored red. Therefore, such weathering crusts are called lateritic (Latin - late - brick).

Among the weathering crusts, two main morphogenetic types are distinguished: areal and linear.

Areal weathering crusts develop in the form of a cover or mantle, occupying vast areas up to tens and hundreds of square kilometers on relatively flat relief surfaces.

Linear weathering crusts have linear (elongated) outlines in plan and are confined to zones of increased fracturing, to faults and contacts of rocks of different composition. Under these conditions, more free penetration of water and the active components contained in them occurs, which causes an intensive process of chemical weathering.

The process of formation of weathering crusts is represented by several sequential and interrelated phenomena:

1. Destruction and chemical decomposition of rocks with the formation of weathering products;

2. Partial removal and redistribution of weathering products;

3. Synthesis of new minerals as a result of the interaction of weathering products during their migration;

4. Metasomatic replacement of parent rock minerals.

Weathering crusts of various ages are associated with many valuable mineral deposits - bauxite, iron ore, manganese, nickel, cobalt, etc.

Cycles of matter in the biosphere. Large (geological) and small (biological) gyres and their role in soil formation

There are two main cycles of substances in nature: large (geological) and small (biogeochemical). ) is due to the interaction of solar energy with the deep energy of the Earth and realizes the redistribution of matter between the biosphere and deeper horizons of the Earth.

Sedimentary rocks formed due to the weathering of igneous rocks in the mobile zones of the earth's crust again submerge into the zone high temperatures and pressures. There they melt and form magma - the source of new igneous rocks. After raising these rocks to earth surface and the action of weathering processes again transforms them into new sedimentary rocks (Fig. 6.7). The symbol of the cycle of substances is a spiral, not a circle.

Solar energy

Igneous rocks

Igneous rocks

Weathering, transfer, deposition, petrification

Crystallization

Sedimentary rocks

Metamorphism

Remelting

Metamorphic rocks

Energy of radioactive decay

This means that the new cycle of circulation does not repeat exactly the old one, but introduces something new, which over time leads to very significant changes.

The great cycle is also the cycle of water between land and ocean through the atmosphere. The moisture evaporated from the surface of the World Ocean (which consumes almost half of the solar energy coming to the Earth's surface) is transferred to land, where it falls in the form of precipitation, which again returns to the ocean in the form of surface and underground runoff. The water cycle also occurs according to a simpler scheme: evaporation of moisture from the ocean surface - condensation of water vapor - precipitation on the same water surface of the ocean.

It is estimated that more than 500 thousand km3 of water annually participate in the water cycle on Earth.

The water cycle as a whole plays a major role in the formation of natural conditions on our planet. Taking into account the trans-pyration of water by plants and its absorption in the biogeochemical cycle, the entire water supply on the Earth decays and is restored in 2 million years (see Fig. 6.10).

The biological cycle is the leading process of soil formation. With the settlement of lower plants (microorganisms, algae, fungi and lichens) on rocks, the processes of weathering (biological weathering) intensify, the amount of water-soluble compounds increases, some of which the body uses to build its body, some is washed out by water, falling into the large geological circulation of substances.

Of the various water-soluble compounds formed initially, plants do not assimilate all the elements, but only those that they need for growth, that is, selectively. After the plants die off, dead organic matter is deposited on the surface and in the upper part of the parent rocks, which gradually accumulate together with the most important elements nutrition necessary for plants.

During the decomposition and mineralization of organic substances that occur simultaneously with weathering, nutrients are released and again become available to plants, which are fully or partially assimilated by subsequent generations of living organisms.

Thus, due to the vital activity of living organisms against the background of a large geological cycle of substances, a small biological cycle arises, and with it a primary change in loose rocks, or the primary process of soil formation. With an increase in the number of organisms per unit area, an increasing number of nutrients are intercepted by them from the geological cycle and retained in the form of living organic matter.

Decomposition and mineralization of organic substances are produced by numerous and diverse in composition microorganisms that release a significant amount of nutrients. At the same time, under the influence of microorganisms, the synthesis of new humic acids and organic compounds characteristic only of soils occurs, which, together with decomposed organic residues, paint the top-bottom soil layers gray, dark gray, and sometimes black.

Under the influence of living organisms and organic acids, profound changes also occur in the mineral part of the parent rock, which over time is divided into layers - horizons that differ from each other both in their properties and in appearance. Ultimately, a completely new natural-historical body is formed.

Thus, as a result of the biological circulation of substances, an exchange of substances and energy occurs between plant and animal organisms and the loose parent rock, on the surface and in the thickness of which, with the participation of microorganisms, new organic substances accumulate, break down and form, profound changes occur in the mineral composition and properties of soils. , which in turn cause changes in the conditions for supplying plants with water and food - this is the essence of the soil-forming process.

the process of formation of soil parent rocks.

Soil formation. The process of soil formation. All rocks covering the surface of the globe, from the very first moments of their formation, under the influence of various processes, began immediately to collapse.

In the process of weathering (hypergenesis), the original appearance of rocks, as well as their elemental and mineral composition, changed. Initially massive (i.e. dense and hard) rocks gradually turned into a fractured state. Examples of rocks crushed as a result of weathering are grit, sand, clay. Becoming fragmented, the rocks acquired a number of new properties and features: they became more permeable to water and air, the total surface of their particles increased in them, increasing chemical weathering, new compounds were formed, including easily soluble in water compounds, and, finally, mountainous breeds acquired the ability to retain moisture, which is of great importance for providing plants with water.

Loose and water-absorbing rocks became a favorable environment for the life of bacteria and various plant organisms. Gradually, the upper layer of the weathering crust was enriched with the products of the vital activity of organisms and their dying off remains. The decomposition of organic substances and the presence of oxygen led to complex chemical processes, as a result of which the elements of ash and nitrogen food accumulated in the rock. Thus, the rocks of the surface layer of the weathering crust (they are also called soil-forming, bedrock or parent rocks) became soil. Thus, the composition of the soil includes a mineral component corresponding to the composition of the bedrock, and an organic component.

Therefore, the beginning of the process of soil formation should be considered the moment when vegetation and microorganisms settled on the products of weathering of rocks. From that moment on, the crushed rock became soil.

Soil-forming, or parent rocks, are loose, weathered rocks, from which soils are formed due to the development of soil formation processes.

The main process in the formation of parent rocks is weathering. It is a long, complex and dynamic process. Different rates and features of the destruction of rocks lead to the formation of unequal loose parent parent rocks, differing in characteristics and properties. These include the following parent rocks.

Eluvium is the products of rock weathering that remain at the place of formation. V mountainous areas on the slopes, eluvium is represented by rock fragments mixed with fine earth.

Aeolian deposits are formed under the influence of wind. These are sands of dunes and dunes, hilly and cumulus sands, sorted by texture with irregular oblique bedding. Buried soils are often found under it.

Loess - deposits of a pale yellow color, carbonate, non-layered, porous, 70-85% composed of dusty particles, well sorted, form vertical walls. The most probable origin of the loess is aeolian. Most often found on the outskirts of deserts, in an arid climate in the foothills.

Deluvial deposits form in the lower parts of the slopes. They are composed of material carried from watersheds by melt and rainwater, are usually well graded and, as a rule, are composed of finer particles than the parent rocks, in watersheds, often humified. Where the watersheds pass into the lower parts of the slopes, deluvial-eluvial deposits are formed.

Proluvial deposits are formed under the influence of temporary mud-stone mudflows, which, breaking out into flat areas, spread out and form fanning cones consisting of dissimilar clastic material. During the formation of temporary streams in ravines, materials are also carried out into wide valleys of gullies or rivers. These deposits are usually more or less sorted, layered, can be distinguished in natural conditions and are called proluvial-alluvial deposits of ravines.

Alluvial deposits are deposits of permanent streams (rivers, large streams). The river valleys are completely composed of alluvial deposits. These deposits are easily identified by the following features: they are layered, well sorted by texture (usually finer at the top than at the bottom), and may contain peat inclusions. Ancient alluvial deposits change over time in the process of soil formation, losing stratification.

Lacustrine deposits form at the bottom of lakes. Very often these are thin silty layered sediments, often mixed with organic residues, forming sapropelic and organic silts and even peat.

Marine sediments of the coasts, as a rule, are composed of coarse material, boulders, pebbles, and are well sorted. Sediments of shallow seas - shelf deposits (most often sandy) have a thin layering, well sorted by texture. In deltas, sandy-silty or silty sediments are often formed, formed from marine and river sediments saturated with organic matter, ferromanganese and phosphate rock formations. In the shallow part, deposits of organic and chemical origin are formed: shell rock, limestone, salt. On the continental slope, variegated silts and clays are formed, containing a significant amount of iron compounds, organic substances and carbonates. They are always saline and, when coming to the surface, contribute to the formation of saline soils.

Glacial deposits are loose rocks transported by a glacier. As a rule, they are not sorted, non-layered, have a different mechanical composition - from sands to heavy loams of red, yellow and red-brown color. They contain a significant amount of often roughly polished un-rounded stones - boulders of various sizes, cartilage, randomly located lenses and layers of different mechanical composition. Deposits can be acidic, neutral and slightly alkaline.

Weathering

Weathering- destruction of rocks. A set of complex processes of qualitative and quantitative transformation of rocks and their constituent minerals, leading to the formation of weathering products. It occurs due to the action on the lithosphere of the hydrosphere, atmosphere and biosphere. If rocks are on the surface for a long time, then as a result of their transformations, a weathering crust is formed. There are three types of weathering: physical (ice, water and wind) (mechanical), chemical and biological.

Physical (mechanical) weathering

"Arch" in Utah (USA), an example of mechanical weathering

The greater the temperature difference during the day, the faster the weathering process takes place. The next step in mechanical weathering is the ingress of water into the cracks, which, when frozen, increases in volume by 1/10 of its volume, which contributes to even greater weathering of the rock. If blocks of rocks fall, for example, into a river, then there they are slowly grinded and crushed under the influence of the current. Mudflows, wind, gravity, earthquakes, volcanic eruptions also contribute to the physical weathering of rocks. Mechanical crushing of rocks leads to the transmission and retention of water and air by the rock, as well as a significant increase in surface area, which creates favorable conditions for chemical weathering.

Chemical weathering

Chemical weathering is a combination of various chemical processes that result in further destruction of rocks and a qualitative change in their chemical composition with the formation of new minerals and compounds. The most important factors in chemical weathering are water, carbon dioxide and oxygen. Water is an energetic solvent for rocks and minerals. The main chemical reaction of water with minerals of igneous rocks is hydrolysis, which leads to the replacement of cations of alkaline and alkaline earth elements of the crystal lattice with hydrogen ions of dissociated water molecules:

KAlSi 3 O 8 + H 2 O → HAlSi 3 O 8 + KOH

The resulting base (KOH) creates an alkaline environment in the solution, in which further destruction of the crystal lattice of orthoclase occurs. In the presence of CO 2, KOH transforms into the carbonate form:

2KOH + CO 2 = K 2 CO 3 + H 2 O

The interaction of water with minerals of rocks also leads to hydration - the attachment of water particles to mineral particles. For example:

2Fe 2 O 3 + 3H 2 O = 2Fe 2 O 3H 2 O

In the zone of chemical weathering, the oxidation reaction is also widespread, to which many minerals containing oxidizable metals are subjected. A striking example of oxidative reactions during chemical weathering is the interaction of molecular oxygen with sulfides in an aqueous medium. Thus, during the oxidation of pyrite, along with sulfates and hydrates of iron oxides, sulfuric acid is formed, which participates in the creation of new minerals.

2FeS 2 + 7O 2 + H 2 O = 2FeSO 4 + H 2 SO 4;

12FeSO 4 + 6H 2 O + 3O 2 = 4Fe 2 (SO 4) 3 + 4Fe (OH) 3;

2Fe 2 (SO 4) 3 + 9H 2 O = 2Fe 2 O 3 3H 2 O + 6H 2 SO 4

Radiation weathering

Radiation weathering is the destruction of rocks by radiation. Radiation weathering affects the process of chemical, biological and physical weathering. Lunar regolith.

Biological weathering

Biological weathering is produced by living organisms (bacteria, fungi, viruses, burrowing animals, lower and higher plants, etc.).

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    WEATHERING, in geology and physical geography, destruction and chemical change of rocks and minerals on the Earth's surface as a result of physical, chemical and organic processes. Influences soil formation and plays a major role in ... ... Scientific and technical encyclopedic dictionary

The weathering process is divided into three types of weathering - physical, chemical and biological. The selection of each weathering is based on some of the factors of weathering, which are decisive. Despite this, all three types of weathering always act together and simultaneously.

1. Physical weathering it is expressed mainly in the mechanical crushing of mineral bodies (rocks, building materials, etc.) without significant changes in their mineral composition. Temperature fluctuations play an important role in this crushing destruction. For example, in deserts, daily temperature fluctuations are very significant, in the daytime up to + 80 ° C, and at night only + 20 ° C. The destruction of rocks and building structures increases when water penetrates into microcracks. When freezing, water increases in volume by 9-11%, a large lateral pressure develops and the rock collapses. This phenomenon is commonly referred to as "frost weathering". Many rocks, especially clayey ones, disintegrate into pieces with alternating wetting and drying. Physical weathering prevails in desert areas and in areas with a cold climate (arctic, high-mountainous regions, etc.).

2. Chemical weathering is expressed in the destruction of rocks, building materials and building structures up to complete disintegration, i.e. to the level of anions and cations, with the simultaneous formation of new mineral formations. The main factors of this weathering are water, oxygen, carbon dioxide, organic acids, etc. Complex chemical processes are associated with these factors - dissolution, oxidation, hydration, carbonitization, and hydrolysis.

The intensity of chemical weathering depends on the area of ​​water exposure, its temperature, and the duration of the processes. Carbonates, sulfates, etc. are most susceptible to this weathering. Chemical weathering has the greatest destructive force in warm and humid climates.

3.Biological weathering sometimes called organic. It manifests itself in the form of mechanical and chemical effects of living and plant organisms on the earth's surface.

Plants produce mechanical destruction by the root system. Even hard rock and concrete slabs can be destroyed by tree roots. In addition to the mechanical force of destruction, the roots of plants have the ability to destroy rocks and building materials with organic acids, which they release both during their growth and after dying off during decomposition processes. Various diggers significantly violate the integrity of rocks.

Biological weathering manifests itself almost everywhere, especially in areas with humid climate which promotes the growth and development of plants.

To a certain extent to biological species weathering should include man-made human activities, in particular, the construction of buildings and structures. Although it should be noted that this activity destroys the surface of the earth's crust through all types of weathering process.