Origin and classification of rocks

Any natural stone is “a rock, a natural formation consisting of individual minerals and their associations.” Studying the composition, origin and physical properties Petrography deals with rocks. According to it, all breeds by origin fall into three main groups:
1. Igneous (“primary” rocks)

- formed directly from magma - a molten mass of predominantly silicate composition, as a result of its cooling and solidification. Depending on the solidification conditions, deep and overflowing ones are distinguished.
Deep
arose as a result of the gradual cooling of magma during high blood pressure inside the earth's crust. Under these conditions, the components of the magma crystallized, resulting in the formation of massive dense rocks with a holocrystalline structure: granite, syenite, labradorite and gabbro.
Poured out
formed as a result of a volcanic eruption of magma, which quickly cooled on the surface at low temperature and pressure. There was not enough time for the formation of crystals, so the rocks of this group have a latent or finely crystalline structure with an abundance of amorphous glass with high porosity: porphyries, basalts, travertine, volcanic tuffs, ash and pumice.

Granite (from Latin granum, grain) - the most common rock. Granite has a distinct granular-crystalline structure and consists mainly of feldspars, quartz, mica and other minerals.

There are 3 different granite structures based on the size of the grains: fine-grained, medium-grained, and coarse-grained. The color of granite can be very different. The most commonly found granite is gray, ranging from light to dark with different shades, but there are also pink, orange, red, bluish-gray and sometimes bluish-green granite. Extremely rare granite with blue quartz. In decorative terms, the most valuable are fine-grained light gray with blue tint, deep dark red and greenish-blue varieties of granites.

2. Sedimentary (or “secondary” rocks)

They are called secondary because they were formed as a result of the destruction of igneous rocks or from waste products of plants and animal organisms.
They can be in the form of chemical precipitation that forms during the drying of lakes and bays, when various compounds precipitate. Over time, they turn into limestone tuffs, dolomite. General Feature of these rocks - porosity, fracturing, solubility in water.
There are also clastic sedimentary rocks. These include cemented sandstones, breccias, conglomerates and loose sands, clays, gravels and crushed stones. Cemented deposits were formed from loose deposits as a result of natural bonding and cementation. For example, sandstone is made from quartz sand with lime cement, breccia is made from cemented crushed stone, and conglomerate is made from pebbles.
Rocks of organic origin are also known: limestone and chalk. They are formed as a result of the vital activity of animal organisms and plants.

Sandstone

For geologists and petrographers, a clastic rock consisting of cemented sand. They come in grey, green, red, yellow, brown and brown. Siliceous sandstones are considered the most durable.
Basically, sandstones are not capable of acquiring a polished texture, so they usually use a chipped or sawn texture, and sometimes a polished one. Sandstones lend themselves well to carving and diamond cutting.
Fine-grained red, chocolate brown and green varieties of sandstone, which are successfully used for external cladding. In Moscow and St. Petersburg architectural monuments built in the 19th and early 20th centuries, facings made of Polish sandstone in gray-green, yellow and pink shades are well preserved. Assumption Square of the Kremlin is lined with Lyubertsy sandstone.
Sandstone is a rather porous material, so it is not advisable to use it for finishing elements in contact with water. It is also not recommended to use it on plinth structures.

3. Metamorphic (modified rocks)

- formed by the transformation of igneous and sedimentary rocks into a new type of stone under the influence of high temperature, pressure and chemical processes.

Among the metamorphic rocks, massive (granular) ones are distinguished, these include marble and quartzite, as well as schistose ones - gneisses and schists.

Marble

The name "marble" comes from the Greek marmaros, shining. This is a granular-crystalline rock that was formed in the bowels of the Earth as a result of the recrystallization of limestone and dolomite under the influence of high temperatures and pressure. In construction, marble is often called not only this stone, but also other dense transitional carbonate rocks. These are, first of all, marble-like or marbleized limestones and dolomites.

Quartzite

These are fine-grained rocks that were formed by the recrystallization of siliceous sandstones and consist mainly of quartz. Quartzite comes in gray, pink, yellow, crimson red, dark cherry and sometimes white.
Quartzite is considered a highly decorative stone, especially raspberry red and dark cherry. The “rock” texture significantly brightens the overall background of this stone, which is often used when combining such products with polished ones of contrasting color.
Quartzite has a very high hardness and is a difficult-to-cut material, but can be polished to a very high quality.
Often used in the construction of unique structures. It was used in the construction of the Church of the Savior on Spilled Blood. For centuries it was also used as a ritual stone. The sarcophagi of Napoleon and Alexander II were made from it, upper part Lenin's mausoleum.

Slate

Dense and hard rock, which was formed from highly compacted clay, partially recrystallized under high and one-sided pressure (from top to bottom, for example). It is characterized by an oriented arrangement of rock-forming minerals and the ability to split into thin plates. The color of slates is most often dark gray, black, gray-brown, red-brown.
Slate is a durable material, it can be processed (laminated into thin plates), some types can also be polished. However, more often it is used without any processing at all, since the split surface is very decorative.
Slate is used in both external and internal cladding. This stone was widely used in famous architectural monuments (floors St. Isaac's Cathedral in St. Petersburg are partly made of slate).

4. Semi-precious stones.

These include mainly rocks called “decorative and ornamental stones”. These are jasper, onyx, opal, malachite, lapis lazuli. They are found much less frequently than ordinary stones and are more valuable. However, to veneer them large plots expensive, so most often these stones are used to decorate small elements: parts of columns, window sills, bathrooms...

Onyx (“nail” translated from Greek) is considered one of the most common decorative and ornamental stones. Onyx has a layered or radical-radiant structure. The color of onyx is white, light yellow, yellow, brown, dark brown, pale green. Striped pattern - alternating stripes different shades. Most marble onyxes are translucent, sometimes to a depth of 30...40 mm. Onyx can be easily processed with cutting and grinding tools and accepts high quality polishing.

Organogenic sedimentary rocks

1. Sedimentary organogenic rocks

On the surface of the Earth as a result of the action of various exogenous factors Sediments are formed, which are further compacted, undergo various physicochemical changes - diagenesis, and turn into sedimentary rocks. Among sedimentary rocks, three groups are distinguished:) clastic rocks, which arise as a result of the mechanical destruction of any rocks and the accumulation of the resulting fragments;) clay rocks, which are the product of predominantly chemical destruction of rocks and the accumulation of clay minerals resulting from this;) chemical (chemogenic) rocks, formed as a result of chemical processes;) organogenic rocks formed as a result of biological processes.

We will talk about sedimentary organogenic rocks. Organogenic rocks are sedimentary rocks formed from the accumulation of waste products and undecomposed remains of living organisms: limestones, shell rocks, fossil coals, guano - decomposed droppings seabirds etc.

When describing sedimentary organogenic rocks, attention should be paid to their mineral composition, which is a defining feature, and to their structure. Also, the most important feature characterizing the structure of sedimentary rocks is their layered texture. The formation of layering is associated with the conditions of sediment accumulation. Any changes in these conditions cause either a change in the composition of the deposited material or a stop in its supply. In the section, this leads to the appearance of layers separated by bedding surfaces and often differing in composition and structure. Layers are more or less flat bodies, the horizontal dimensions of which are many times greater than their thickness (thickness). The thickness of the layers can reach tens of meters or not exceed fractions of a centimeter.

1.1 Origin

The formation of sediments, from which sedimentary rocks arise, occurs on the surface of the earth, in its near-surface part and in water basins.

The process of formation of sedimentary rock is called lithogenesis and consists of several stages:

) formation of sedimentary material;

) transport of sedimentary material;

) sedimentogenesis - accumulation of sediment;

) diagenesis - transformation of sediment into sedimentary rock;

) catagenesis - the stage of existence of sedimentary rock in the stratisphere zone;

) metagenesis - the stage of deep transformation of sedimentary rock in the deep zones of the earth's crust.

The bulk of organogenic rocks arose in marine and continental reservoirs of varying salinity, depth and size, as well as as a result of the action of chemical processes and the vital activity of organisms on land and sea. All breeds of chemogenic and organogenic origin are connected by mutual transitions and have a mixed chemogenic-organogenic origin. The classification of rocks of chemogenic and organogenic genesis is carried out according to their chemical composition.

Let us consider the formation of some organogenic rocks. For example, limestone. Huge deposits of limestone, formed millions of years ago from the skeletons of marine animals, make up approximately 20% of the total sedimentary rocks. Limestones were formed as a result of long-term geochemical processes. Rivers annually carry many millions of tons of lime into the seas in suspended and dissolved form. When river water meets salty sea water, a kind of “geochemical barrier” is formed, on which soluble compounds, including lime, precipitate, mixing with silt. Some of the calcium bicarbonate remains dissolved and is gradually absorbed by marine plants and animals. As a result, over millions of years, a huge number of shells of dead mollusks and corals formed colossal accumulations of calcium carbonate. This is how various limestones arose, among which, based on the rock-forming organisms, they are distinguished as coral, shell, nummulitic, bryozoan, algal, etc.

Rice. 1. Formation of an oil deposit

Or the formation of another organogenic rock, such as oil. (Fig. 1) The main conditions for the development of the process of oil formation, called thermocatalysis, are the lowering of sedimentary rocks containing organic residues to great depths, the influence of high temperatures and pressures prevailing at these depths and the catalytic role of the host rocks themselves, accelerating the reactions of decomposition and chemical processing of organic substances. When oxidized on the surface, oil turns into tar and asphalt.

Another example is the formation of oil shale. Formation begins from the moment of accumulation of organic residues. The “parents” of shale are tiny algae moved by waves or (phytoplankton), sometimes algae of underwater meadows (phytobenthosis) or lower representatives of the animal world (phyankton). Oil shale began to form 130-140 million years ago in the Lower Volgian age of the Jurassic period. The Jurassic seas were shallow, warmed well, and were densely populated with algae, which served as habitat for numerous invertebrate and vertebrate organisms. After death, the organisms sank to the bottom in silt-clay sediment, which served as the basis for the formation of oil shale. If you break off a piece of oil shale, you can see a large number of prints of algae, worm passages, ammonites, belemnites, bivalves, scales of fossil fish, vertebrae of ichthyosaurs, plesiosaurs and other organisms.

Rice. 2. Coal formations

The variety of types of vegetation that grew on Earth in different geological eras and in different climatic zones, the conditions of burial and transformation in peat deposits determined the widest range of properties of the organic mass, which was the starting material, and subsequently became coal itself. The formation of peat deposits occurred (and is happening now) in swamps various types: in coastal sea, lake, river valleys. Peat bogs were periodically flooded with waters that brought this or that amount of mineral impurities, both in suspended and chemically dissolved states. The intensity of their introduction and the composition of the rocks surrounding the peat bogs determined the ash content of coal and the presence of harmful and beneficial substances in its composition. chemical elements, such as sulfur, phosphorus, germanium, allium, etc. Further, due to the subsidence of the Earth’s crust, peat bogs were covered by a thickness of so-called sedimentary rocks and sank to various depths, where, under conditions of significant pressure and temperature, the original organic matter acquired properties inherent in one or another grade of coal.

1.2 Classification

Organogenic rocks (biogenic rocks) - consist of the remains of animal and plant organisms or their metabolic products.

Organisms have the ability to concentrate certain compounds to form skeletons or tissues that are preserved in fossil form. According to the material composition, organogenic rocks can be distinguished:

) carbonate;

) siliceous;

) phosphate;

) oil shale;

I propose to consider each group separately.

Organogenic carbonate rocks (limestones) consist of shells of foraminifera, corals, bryozoans, brachiopods, mollusks, algae and other organisms. Their peculiar representatives are reef limestones that make up atolls, barrier reefs, etc., as well as chalk.) Reef limestones - Currently, most of the reefs are built by corals, but hundreds of millions of years ago the main builders of reefs were bryozoans (colonial aquatic, mainly marine, attached animals) and algae.) Chalk is a soft limestone with a very fine texture, which is usually white or light gray in color. It is formed primarily from the calcareous shell remains of microscopic marine organisms such as foraminifera or the calcareous remains of numerous species of seaweed.

Siliceous rocks consist of hydrous silica (opal). Among them are:) Diatomite - formed from the shells of diatoms and partly from the skeletons of radiolarians and sponges, between which the finest silt and clay were deposited. Consists primarily of amorphous silica in the form of the mineral opal.) Spongolites are rocks that typically contain more than 50% siliceous sponge spicules. Their cement is siliceous, made of opal rounded bodies, or clayey, slightly calcareous, often including secondary chalcedony.) Radiolarites are siliceous rocks, more than 30% consisting of radiolarian skeletons, which form radiolarian silt in modern oceans. In addition to radiolarians, they include single sponge spicules, rare diatom shells, coccolithophores, opal and clay particles. During recrystallization, radiolarites turn into jasper.) tripoli - a rock of predominantly colloidal-chemogenic origin, consisting of tiny grains of opal;) opoka - a solid siliceous rock formed as a result of recrystallization and cementation of diatomite or tripoli.

Organogenic phosphate rocks are not widespread. These include shell rocks from phosphate shells of Silurian brachiopods - obolid, accumulations of fossil vertebrate bones known in sediments of different ages, as well as guano - products of decomposition of bird droppings, thicknesses of which usually accumulate on islands in dry climates.

Coal forms from the accumulation and preservation of plant materials, usually in swamps. Coal is a combustible rock and, together with oil and natural gas, is one of the three most important fossil fuels. Coal has a wide range of uses, the most important being for electricity generation.

Depending on the stage of metamorphism in Russia, these types of coal are distinguished. (Table 1)

Table 1. Stages of coal metamorphism

Oil shale is a mineral that occurs at relatively shallow depths, belongs to the group of solid caustobioliths and consists of organic matter (10-50% by weight) and a mineral part. Both the organic and mineral parts of shale are of industrial value, the main components of which are carbonates and aluminosilicates. Oil shale is thin-layered, has a dark gray or brown color, and when burned, emits the smell of bitumen.

Oil is an organogenic rock. Source material for the formation of oil is putrefactive silt, or sapropel, which accumulates at the bottom of stagnant bodies of water: lakes, sea bays, lagoons, sometimes also in the coastal areas of the bottom of open sea basins as a result of the death of various lower plants and animals, mainly planktonic microorganisms inhabiting the waters of the seas and oceans .

Organogenic rocks can also be divided by structure. In these rocks great value has the form components, which is determined by the nature of the organisms. Among the rocks of this group, structures are distinguished: crinoid, coral, pelecypod, bryozoan, foraminiferal, algal, mixed, etc. Depending on the preservation of the fragments in the rock, the following structures are distinguished:

Biomorphic - good preservation of organic residues. In terms of the size of the components, they can be very different depending on the organisms - from very large (for example, corals) to the smallest (for example, diatoms);

Detritus (detritus) - the rock is composed of fragments of the skeletons of organisms.

In turn, among rocks with a detritus structure, they distinguish:) coarse detritus rocks are composed of unrounded fragments, often clearly visible to the naked eye and easily identified under a microscope. The sizes of fragments most often range from several millimeters to approximately 0.05 mm.) fine detritus. are composed of tiny fragments of organisms (usually 0.05 mm and smaller), indistinguishable to the naked eye and for the most part undetectable under a microscope in thin section.

The organogenic-clastic structure is distinguished by the fact that shell fragments are mostly well rounded and almost the same size (0.5 -0.1 mm).

2 . Distribution of organogenic rocks in the Krasnodar region

More than 60 types of minerals have been discovered in the depths of the region. They mainly occur in foothill and mountainous areas. There are oil reserves natural gas, marl, iodine-bromine waters, marble, limestone, sandstone, gravel, quartz sand, iron and apatite ores, rock salt and other minerals. Ministry natural resources The Russian Federation has approved a list of common minerals Krasnodar region, below is a list of some of them:

Diatomite;

Limestones;

Marl;

Shell rock;

Shales (except combustible);

Peat (except for those used for medicinal purposes).

2.1 Deposits in the Krasnodar region

Hydrocarbon and energy raw materials

Hydrocarbon and energy raw materials. 280 oil (Fig. 3) and gas fields have been identified in the region. Oil deposits are located in the thickness of sedimentary rocks and are located at depths from 700 to 5200 m. According to geological services, by 1995, 218 million tons of oil were produced in the region. Of more than 70 explored oil fields with a reserve of 41.8 million tons, 66 are in operation. The forecast estimate of oil reserves is approximately three times higher than the explored ones.

An example of one of the largest oil fields Novodmitrievskoe (Seversky district) can serve: it has a length of approximately 10 km, a width of 2.5 km, and the thickness of oil-bearing rocks (oil-bearing level) is 450 m. Oil lies here at a depth of 2400-2800 m.

Coal deposits were found in mountainous areas in the basins of the Belaya, Malaya and Bolshaya Laba rivers. Coal occurs in the form of seams with a thickness of 0.5-0.9 m. But due to the low calorific value, the extraction of Kuban coal is not profitable.

Manifestations of low and medium quality oil shale were discovered in the area between the Bolshaya and Malaya Laba rivers. According to geologists' forecasts, shale reserves amount to 136.25 million tons. Peat deposits were discovered in the lower reaches of the Kuban (Grivenskoye), in the Novokubansky region along the river. Urup, as well as at the mouth of the Mzymta and Psou rivers on the Black Sea coast. The development of oil shale and peat deposits is also unprofitable due to their low energy value and small reserves.

Limestones

Limestones and chalk are widely used in the chemical industry for the production of soda, calcium carbide, caustic potassium, caustic soda, in the production of mineral fertilizers and other products. There is one known limestone deposit on the territory of the Krasnodar Territory (Pravoberezhnoe). It is located in the Labinsky district, on the right bank of the river. Malaya Laba, 4 km east of the railway. Shedok station. The useful strata are the limestones of the Turonian and Coniacian stages of the Upper Cretaceous, the thickness of which ranges from 0 to 73 m. The chemical composition of the limestones of the productive strata (in%): CaO - 54.2; MgO - 0.3; SiO 2 - 1.4; R 2 O 3 - 0.7; Na 2 O - 0.04; K 2 O - 0.07; SO 3 - 0.1; P - 0.024. Due to its properties, limestones are suitable for soda production, and can also be used in the sugar industry and for the production of lime and cement. Raw material reserves amount to 244,314 thousand tons.

Seashell

Seashell deposits in the Krasnodar Territory are confined to the coast Sea of ​​Azov and its estuaries and, to a lesser extent, the estuaries of the Taman Peninsula. Genetically, they represent modern marine sediments washed up by sea currents and surf along coastline in the form of shafts and braids. Such accumulations of seashells are several kilometers wide and long and several meters thick. The main component of seashell deposits are calcareous shells (whole or fragments) of modern mollusks containing small amounts of sand, clay, organic residues, etc. as impurities. Depending on the granulometric composition and contamination, seashell can be used for ballasting railway tracks, for burning lime, for producing wall blocks and for preparing feed flour and cereals.

33 seashell deposits have been described in the Krasnodar region. Of these, only 6 deposits are on the balance sheet of reserves (Kirpilskoye, western section; Slobodkinskoye, Khanskoye, Dolzhanskoye; Zaboyskoye and Chernoerkovskoye) with total reserves equal to 4220 thousand m 3. Of these, the Kirpilskoye, Zaboyskoye and Chernoerkovskoye fields are being developed. They are located on the territory of Yeisk and Primorsko-Akhtarsky districts. The raw materials from all of the above deposits are suitable for use as feed flour and cereals.

The largest deposit in the Krasnodar region is the Dolzhanskoye seashell deposit. It is located in the Yeisk district, 3 km northwest of the village of Dolzhanskaya and 45 km west of the city of Yeisk, on the Dolgaya spit. The useful stratum is composed of mid-Quaternary and modern marine sediments, represented by whole and crushed seashells, with an admixture of sand. Shell accumulations occur in layers in the form of a spit 4 km long and 30 to 1200 m wide; The thickness of the useful thickness is 2.65-6.1 m. Shell deposits are suitable for feeding birds. The deposit constitutes a reserve.

Building stone .

There are 41 known deposits of building stone in the Krasnodar region. 25 deposits are being developed, 7 are being prepared for development, one is being explored and 8 are reserves. Such deposits are known as: Medvezhyegorskoye (6 km from Derbentskaya), Severnaya Gora (4 km from Ilskaya), Pravoberezhnoe (4 km from Shedok), Khodzhokhskoye (12 km from Kamennomostsky). The total reserves of building stone are 213.15 million m³, while the reserves of limestone used to produce crushed stone and rubble stone are 118.886 million m³; reserves of sandstones suitable for producing crushed stone - 39.123 million m³. Limestones are also used for the needs of sugar production.

2.2 Mining of main organogenic rocks in the Krasnodar region

Krasnodar region is the birthplace of the domestic oil industry. 1.7 - 1.9 million tons of oil are extracted from the depths of the region annually, natural gas production has been increased to 3 billion m³. The table below shows how oil production in the Kuban grew steadily, with the exception of the war years and the period of the economic crisis of the 90s of the 20th century.

Table 2. Growth rate of oil production in Kuban

All oil fields currently being developed in the Krasnodar Territory are located on land. Oil production in the region from small fields amounted to 74%, and from the large Anastasievsko-Troitskoye field - 26% of the annual volume. In recent years, the largest increase in oil (and gas) reserves and production has been achieved through prospecting and exploration of the Pribrezhno-Sladkovsko-Morozovsky group of fields (33.8% of the annual oil production volume). The average supply of oil reserves in the region, at the current level of production, is about 22 years.

The preparation of new industrial hydrocarbon reserves in the region, at the present stage, is complicated by the fact that the search is carried out mainly for small and complexly constructed deposits, reaching significant depths, in areas with difficult mining and technical conditions.

The main deposits explored in the region are at the final stage of development. The Krasnodar region is one of the oldest oil and gas producing regions in Russia. Most of its deposits with the main reserves of raw materials were put into operation more than 30-40 years ago and continue to be exploited to this day.

The main region of the coal industry is the eastern wing of Donbass in the Rostov region. (Shakhty, Novoshakhtinsk, etc.). Coal production is about 7 million tons (2% of all-Russian production).” Coal (coking and steam coal) is mined at great depths in conditions of low seam thickness, which leads to high costs and a limited (in the south of Russia) market for these coals. A further decline in production is unlikely to be stopped, since production conditions are difficult and rich deposits have already been developed.

Unwanted limestone mining is taking place on the eastern slope

Rice. 4. Limestone mining

Dzykhrinsky karst massif, in the 24th quarter of Sochi national park(Fig. 4), which is part of a specially protected zone. Here, on the rocks of the Shakhginsky gorge, grow several species of plants listed in the Red Book of Russia and the Krasnodar Territory. The quarry is developed using excavators; the stone is loaded onto dump trucks and transported to the crusher located above Yermolovka.

3 . Application in industry, construction and agriculture

Sedimentary rocks are of extremely important practical and theoretical importance. In this regard, no other rocks can compare with them.

Sedimentary rocks are the most important in practical terms: they are minerals, foundations for buildings, and soils.

The scientific and practical significance of coals and oil shale is extremely great: they and their components are used for periodization of the history of the Earth, in stratigraphic studies (correlation of sections and determination of age), facies analysis and paleogeography, in stage analysis of vitrinite reflectivity, etc.

The practical importance of coal cannot be overestimated. This is primarily the main source of energy. Only in the mid-50s did coal give way to oil, but there has already been a tendency for it to become a leader again, and this prospect is ensured by the enormous coal resources on Earth (almost 15 or even 30 trillion tons), an order of magnitude greater than the resources of oil and gas. taken together (Golitsyn, Golitsyn, 1989, p. 42). With the imminent reduction in oil production, its substitute will be oil shale (OS), “the total world reserves of which are 450 trillion. t" (UN, 1967), which is an order of magnitude greater than the reserves of coal and oil (92 billion tons), although this number also included the predominant inorganic part in their composition. The HS contains from 26 to 53 trillion. tons of shale resin (according to various estimates; Golitsyn, Prokofieva 1990, p. 15), if we take 4% as the lower limit of resin content (and the upper limit reaches 35% in the kukersites of the Baltic states and in the Glen Davis deposit in Australia). More than half (53%) of HS resources are concentrated in the United States, especially in the richest Green River basin (Rocky Mountains). From coal alone, if all of it is mined, it is possible to build a cube with an edge of 21 km (a volume of more than 10 thousand km3, which is almost 3 times higher than Everest (Golitsyn, Golitsyn, 1989, p. 42). Coal resources have been calculated to depth 1800 m (sometimes up to 2000 m), brown - 600, lignite - 300 m.

Oil shale has been used as a fuel since at least 1694. As a source of energy, it is the hope of humanity. Their heat of combustion is from 4-5 to 20-25 MJ/kg (Golitsyn, Prokofieva, 1990, p. 7). In terms of heat of combustion (more than 15 mJ/kg), resin yield (up to 25-30%), low sulfur content (less than 1%), low ash content and humidity, the Baltic kukersites are the best in the world. The burning of oil shale is limited by its sulfur content, reaching 10% (poisoning nature with sulfuric acid), and high ash content and humidity (up to 30%). Shales are valuable chemical raw materials, especially due to the high content of phenols, which are difficult to obtain from oil. Dictyonema shales of the Baltic region are interesting for their content of molybdenum, vanadium, silver, lead, copper and other rare and trace elements (Golitsyn, Prokofieva, 1990, p. 25, etc.).

Peat is a unique material. Despite the fact that it has been known for many hundreds of years and has been actively used by mankind in industry as fuel and in agriculture as fertilizer, only recently have it been discovered unique properties peat Peat turned out to be an unsurpassed natural antiseptic and a fantastically excellent raw material for the production of natural fabrics.

Its huge and constantly renewable reserves can be considered as gigantic deposits of unique sorbent material.

Peat can large quantities process oil into a harmless substance. During the tragedy in the Gulf of Mexico, it was necessary to simply fill the spot with large quantities of peat, which could turn into silt, which would stimulate the growth of algae.

Peat is practically not used for cleaning waste water from metals and organics, although its low cost and high purity may make it the most sought-after material in the world. Moreover, the spectrum of metal sorption by it is very wide, from lithium to uranium. Almost all toxic organic substances can be trapped in peat.

The practical significance of carbonatolites is that they are all minerals. Limestone, chalk and dolomite are used in ferrous and non-ferrous metallurgy, the chemical industry, in the production of cement and other binding materials, for the production of rubber, glass, sugar, for the production of limestone flour for the reclamation of acidic soils, mineral fertilizing in livestock and poultry farming, as well as in other industries, where the requirements for carbonate raw materials are determined mainly by its chemical and mineral composition. Due to their significant distribution and diversity of properties, carbonate rocks are used in large quantities in various industries and agriculture. Also, one of the main consumers of carbonate rocks is the construction industry. It is used for finishing facades (Fig. 5), for the production of various sealants, putty and plaster mixtures. The total number of explored reserves of carbonate raw materials, taken into account by various reserve balances in Russia, currently exceeds 60 billion tons, more than 1,900 deposits have been explored, and about 570 are being developed.

Siliceous rocks (diatomites, tripoli, opoka), due to the presence of amorphous active silicic acid in their composition, have a number of very valuable properties: fine-porous structure, relatively low volumetric mass and thermal conductivity. The combination of these properties predetermines their effective use in production building materials(Fig. 6) and in particular during production ceramic products. Experience shows that the use of siliceous and clayey rocks in a mixture with carbon-containing waste can significantly improve the physical and mechanical properties of ceramics due to the creation of a reducing environment during the firing process and the transition of ferric iron into a more fusible divalent iron, which ensures more intense sintering when the temperature is reduced by 100 - 1500C.

Conclusion

The purpose of this course work was to study this type of sedimentary rocks as organogenic. The goal has been achieved - the origin, composition and characteristics, as well as the main deposits in the Krasnodar region, have been considered.

Despite the diversity of organogenic rocks, the most common and most important ones are present in the work.

More than three-quarters of the continental area is covered with sedimentary rocks, so they are most often dealt with during geological work. In addition, the vast majority of developed mineral deposits, including oil and gas, are associated with sedimentary rocks. They contain well-preserved remains of extinct organisms, from which one can trace the history of the development of the Earth. Organogenic rocks have also been found wide application in many industries, construction and agriculture.

Based on the work done, it can be concluded that organogenic rocks used by humans have unique and useful properties that make these rocks relevant today.

References

sedimentary mountain petroleum organogenic

1. Kuznetsov V.G. Lithology. Sedimentary rocks and their study. - M.: Nedrabusinesscenter, 2007.

2. Sokolovsky A.K., Korsakov A.K., Fedchuk V.Ya. and others. General geology. M.:KDU, 2006.

3. Krasilshchikov Ya.S. Fundamentals of geology, prospecting and exploration of mineral deposits. - M.: Nedra, 1987.

4. Shvanov V.N., Frolov V.T., Sergeeva E.I. and others. Systematics and classification of sedimentary rocks and their analogues. St. Petersburg: Nedra, 1998.

Rocks formed as a result of the vital activity of organisms are called organic sedimentary rocks. They are formed from the remains of plants and animals deposited at the bottom of reservoirs. These include limestone, coal, oil, oil shale, peat, shell rock, chalk...

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Organic thermal insulation materials and products- - are produced from various plant materials: wood waste (shavings, sawdust, slabs, etc.), reeds, peat, flax tow, hemp, animal wool, and also based on polymers. [Dictionary of building materials and products for students... ...

A complex of organic compounds that make up the soil (See Soil). Their presence is one of the main features that distinguishes the soil from the parent rock. Formed during the decomposition of plant and animal materials and... ...

Rocks formed by the accumulation of minerals, mainly from an aqueous environment, through compaction and cementation. There are: chemical sediments (gypsum, rock salt), clastic sediments (gravel, sand, clayey rocks), cemented… … Construction dictionary

Binding organic materials- – substances of organic origin that have the ability, under the influence of physical or chemical processes, to transform from a plastic state to a solid or low-plasticity state. There are bitumen, tar and polymer organic binders... ... Encyclopedia of terms, definitions and explanations of building materials

Rocks that arose by the deposition of matter in the aquatic environment, less commonly from the air and as a result of the activity of glaciers on the land surface, in sea and ocean basins. Precipitation can occur mechanically (under the influence of... ... Great Soviet Encyclopedia

Organic materials- – materials obtained from living nature: flora or fauna. In the field of construction they use construction materials from wood and plastic, binders from bitumen, tar and polymers, fillers from wood waste and others... ... Encyclopedia of terms, definitions and explanations of building materials

Clastic rocks, sedimentary rocks consisting entirely or predominantly. from fragments of various rocks (igneous, metamorphic or sedimentary) and minerals (quartz, feldspars, mica, sometimes glauconite, volcanic... ... Great Soviet Encyclopedia

A type of sedimentary rock consisting of fragments of other rocks and minerals (usually quartz, feldspars, micas, sometimes glauconite, volcanic glass). There are cemented rocks (conglomerates and breccias), in which... ... Geographical encyclopedia

A mixture of high molecular weight organic compounds of various structures. The starting materials for their production are oil, bitumen-containing rocks, oil shale (to produce bitumen), coal, wood and peat (to produce tar).... ... Construction dictionary

This article may contain original research. Add links to sources, otherwise it may be set for deletion. More information may be on the talk page. (May 25, 2011) ... Wikipedia

Sedimentary rocks (SRP) are formed during the mechanical and chemical destruction of igneous rocks under the influence of water, air and organic matter.

Sedimentary rocks are rocks that exist under thermodynamic conditions characteristic of the surface part of the earth's crust, and are formed as a result of redeposition of weathering products and destruction of various rocks, chemical and mechanical precipitation from water, the vital activity of organisms, or all three processes simultaneously.

Under the influence of wind, sun, water and due to temperature changes, igneous rocks are destroyed. Loose fragments of igneous rocks form loose deposits and from them layers of sedimentary rocks of clastic origin are formed. Over time, these rocks become compacted and form relatively hard, dense sedimentary rocks.

More than three quarters of the continental area is covered by geological rocks, which is why they are most often dealt with during geological work. In addition, the vast majority of mineral deposits are genetically or spatially related to the UGP. In the UGP, the remains of extinct organisms are well preserved, from which one can trace the history of the development of various parts of the Earth. Sedimentary rocks contain fossils (fossils). By studying them, you can find out what species inhabited the Earth millions of years ago. Fossils (lat. fossilis - fossil) - fossil remains of organisms or traces of their vital activity belonging to previous geological eras.

Rice. Fossils: a) trilobites (marine arthropods found in the Cambrian, Ordovician, Silurian and Devonian periods) and b) fossilized plants.

The starting material for the formation of UCP are minerals, formed by the destruction of pre-existing minerals and rocks of igneous, metamorphic or sedimentary origin and transported as particulate matter or dissolved matter. The science of “Lithology” studies sedimentary rocks.

Various geological factors participate in the formation of sedimentary rocks: destruction and redeposition of destruction products of pre-existing rocks, mechanical and chemical precipitation from water, and the vital activity of organisms. It happens that several factors take part in the formation of a particular breed. However, some rocks can be formed in different ways. Thus, limestones can be of chemical, biogenic or clastic origin.

Examples of sedimentary rocks: gravel, sand, pebbles, clay, limestone, salt, peat, oil shale, hard and brown coal, sandstone, phosphorite, etc.

Rocks are not eternal and they change over time. The diagram shows the process of rock cycling.

Rice. The process of rock cycling.

Based on their origin, sedimentary rocks are divided into three groups: clastic, chemical and organic.

Clastic rocks are formed in the processes of destruction, transport and deposition of rock fragments. These are most often screes, pebbles, sands, loams, clays and loess. Clastic rocks are divided by size:

· coarse clastic(> 2 mm); acute-angled fragments - gruss, crushed stone, cemented by clay shales, form breccias, and rounded fragments - gravel, pebbles - conglomerates);

· medium clastic(from 2 to 0.5 mm) – form sands;

fine-clastic or dusty– form loess;

· fine clastic, or clayey (< 0,001 мм) – при уплотнении превращаются в глинистые сланцы.

Sedimentary rocks of chemical origin– salts and deposits formed from saturated aqueous solutions. They have a layered structure and consist of halide, sulfuric acid and carbonate minerals. These include rock salt, gypsum, carnallite, opoka, marl, phosphorites, iron-manganese nodules, etc. (Table 2.4). They can form in a mixture with clastic and organic sediments.

Marl is formed when calcium carbonate is washed out of limestone, contains clay particles, is dense and light-colored.

Iron-manganese nodules are formed from colloidal solutions and under the influence of microorganisms and create spherical deposits of iron ores. Phosphorites are formed in the form of pineal nodules irregular shape, at the merger of which phosphorite slabs appear - deposits of phosphorite ores of gray and brownish colors.

Rocks of organic origin are widespread in nature - these are the remains of animals and plants: corals, limestones, shell rocks, radiolarians, diatoms and various black organic silts, peat, hard and brown coals, oil.

The sedimentary thickness of the earth's crust is formed under the influence of climate, glaciers, runoff, soil formation, the vital activity of organisms, and is characterized by zonality: zonal bottom silts in the World Ocean and continental sediments on land (glacial and fluvio-glacial in the polar regions, peat in the taiga, salts in desert, etc.). Sedimentary strata accumulated over many millions of years. During this time, the zonation pattern changed many times due to changes in the position of the Earth's rotation axis and other astronomical reasons. For each specific geological epoch, it is possible to reconstruct a system of zones with the corresponding differentiation of sedimentation processes. The structure of the modern sedimentary shell is the result of the overlap of many zonal systems of different times.

In most of the territory globe soil formation occurs on sedimentary rocks. In the northern part of Asia, Europe and America, vast areas are occupied by rocks deposited by glaciers of the Quaternary period (moraine) and products of their erosion by melted glacial waters.

Morainic loams and sandy loams. These rocks are distinguished by their heterogeneous composition: they represent a combination of clay, sand and boulders various sizes. Sandy loam soils contain more Si02 and less other oxides. The color is mostly red-brown, sometimes fawn or light brown; the build is tight. A more favorable environment for plants is moraine deposits containing calcareous boulders.

Cover clays and loams- boulder-free, fine-earth rocks. They consist predominantly of particles less than 0.05 mm in diameter. The color is brownish-yellow, most of them have fine porosity. Contains more nutrients than the sands described above.

Loess-like loams and loess are boulder-free, fine-earth, carbonate, fawn and yellow-fawn, finely porous rocks. Typical loess is characterized by a predominance of particles with a diameter of 0.05-0.01 mm. There are also varieties with a predominance of particles with a diameter of less than 0.01 mm. The calcium carbonate content ranges from 10 to 50%. The upper layers of loess-like loams are often free of calcium carbonate. The non-carbonate part is dominated by quartz, feldspars, and clay minerals.

Red weathered bark. In countries with tropical and subtropical climates, fine-earth sediments of Tertiary age are widespread. They are distinguished by a reddish color, highly enriched in aluminum and iron and depleted in other elements.

Typical example: Laterites, a red-colored rock rich in iron and aluminum in hot and humid tropical areas, formed by the weathering of rocks.

Rice. Lateritic weathering crusts

Bedrock. In large areas, marine and continental rocks of pre-Quaternary age emerge on the surface, collectively called “bedrock.” The named breeds are especially common in the Volga region, as well as in the foothills and mountainous countries. Among the bedrock, carbonate and marly loams and clays, limestones, and sandy deposits are widespread. It should be noted that many sandy bedrocks are enriched in nutritional elements. In addition to quartz, these sands contain significant quantities of other minerals: micas, feldspars, some silicates, etc. As a parent rock, they differ sharply from ancient alluvial quartz sands. The composition of bedrock is very diverse and insufficiently studied.

Rocks are minerals and their compounds. It is impossible to imagine our planet without the minerals that actually form it.

Classification system

There are a huge number of types of rocks, divided into groups. Genetically distinguished:

• sedimentary;
• metamorphic;
• igneous.

The latter are further divided into three classes:

• plutonic;
• hypabyssal;
• volcanic.

Subgroups can be divided into:

• sour;
• average;
• basic;
• ultrabasic.

It is almost impossible to compose full list rocks, considering all the species existing on Earth, there are so many of them. In this article, we will make an attempt to structure information about the most interesting and frequently occurring types.

Metamorphic rocks: list

These are formed under the influence of the inherent earth's crust Since transformations occur when substances are in the solid phase, they are visually invisible. During the transition, the structure, texture, and composition of the original rock change. For such changes to occur, you need a successful combination:

• heating;
• pressure;
• influence of gases, solutions.

There is metamorphism:

• regional;
• contact;
• hydrothermal;
• pneumatolyte;
• dynamometamorphism.

Amphibolites

These minerals are also formed by plagioclase. The first is classified as ribbon silicate. Visually, amphibolites are schists or arrays of colors ranging from dark green to black. The color depends on the ratio in which dark-colored components are present in the mineral. Minor minerals of this group:

• pomegranate;
• magnetite;
• titanite;
• zoisite.

Gneisses

In its structure, gneiss is extremely close to granite. It is not always possible to visually distinguish these two minerals from each other, since gneiss copies granite and is close to it in physical parameters. But the price of gneiss is significantly lower.

Gneisses are widely available and therefore are useful in construction. Minerals are diverse and aesthetic. The density is high, so stone can be used as concrete aggregate. With low porosity and low ability to absorb water, gneisses have increased resistance to freezing. Since weathering is also small, the use of the mineral as a facing is allowed.

Slates

When compiling a list of rocks, shales must be mentioned among the metamorphic ones. There are such types of them as:

• clayey;
• crystalline;
• talc;
• chlorite.

Thanks to the unusual structure and aesthetics of this stone, slate has become indispensable in recent years. decorative material used in construction.

Shales are a fairly large group of rocks. List of names of varieties actively used by humanity for various purposes (mainly in construction, repair, reconstruction):

• siltstone;
• golds;
• serpentinite;
• gneiss;
• and phyllite schists.

Quartzite

This stone is known for its durability as it is formed from quartz with added impurities. Quartzite is formed from sandstone when the original elements of the mineral are replaced by quartz during regional metamorphism.

In nature, quartzite occurs in a continuous layer. Frequent impurities:

• hematite;
• granite;
• silicon;
• magnetite;
• mica.

The richest deposits are found in:

• India;
• Russia;
• Canada.

Main features of the mineral:

• resistance to frost, moisture, temperatures;
• strength;
• safety, environmental cleanliness;
• durability;
• resistance to alkalis and acids.

Phyllite

Not the last place in the list of rocks belongs to phyllites. They occupy an intermediate position between clayey and mica shales. The material is dense and fine-grained. At the same time, the stones are obviously crystalline, they are characterized by a pronounced foliation.

Phyllites have a silky shine. Color scheme - black, shades of gray. Minerals are broken into thin slabs. Phyllites include:

• mica;
• sericite

There may be grains, crystals:

• albite;
• andalusite;
• grenade;
• quartz.

Phyllite deposits are rich in France, England and the USA.

Sedimentary rocks: list

Minerals of this group are located mainly on the surface of the planet. To form, the following conditions must be met:

• low temperatures;
• precipitation.

There are three genetic subtypes:

• clastics, which are rough stones formed by the destruction of rock;
• clayey, the origin of which is associated with the transformation of minerals of the “silicate” and “aluminosilicate” groups;
• biochemo-, chemo-, organogenic. These are formed during precipitation processes in the presence of appropriate solutions. Microscopic and not only organisms and substances of organic origin also take an active part in this. The role of waste products is important.

Chemogenic ones include:

• halide;
• sulfate.

List of rocks of this subgroup:

• gypsum;
• anhydrites;
• sylvinite;
• rock salt;
• carnallite.

The most important sedimentary rocks are:

• Dolomite, similar to dense limestone.
• Limestone consisting of potassium carbonate with an admixture of the same magnesium and a number of inclusions. The parameters of a mineral vary and are determined by the composition and structure, as well as the texture of the mineral. Key Feature- increased compressive strength.
• Sandstone formed by mineral grains bound together by naturally occurring substances. The strength of the stone depends on the impurities and what kind of substance became the binder.

Volcanic rocks

Volcanic rocks must be mentioned. A list of these is created, including minerals formed during the process. In this case, the following are distinguished:

• poured out;
• clastic;
• volcanic.

• andesite;
• basalt;
• diabase;
• liparite;
• trachyte.

Pyroclastic, that is, clastic, includes:

• breccias;
• tuffs.

Almost complete alphabetical list volcanic rocks:

• anorthosite;
• granite;
• gabbro;
• diorite;
• dunit;
• comatitis;
• patches;
• monzonite;
• obsidian;
• pegmatite;
• peridotite;
• perlite;
• pumice;
• rhyolite;
• syenite;
• tonalite;
• felsite;
• slag.

Organic rocks

Organic rocks are formed from the remains of living beings, the list of which rightfully begins with the most significant substance - chalk. These rocks belong to the group of sedimentary rocks already discussed above, and are important not only from the point of view of applicability for solving different tasks human, but also as rich archaeological material.

The most important subtype of this rock type is chalk. It is widely known and actively used in everyday life: it is used to write on blackboards in schools.

The chalk is formed by calcite, which previously made up the shells of coccolithophorid algae that lived in ancient seas. These were microscopic organisms that inhabited our planet in abundance about a hundred million years ago. At that time, algae could float unhindered across vast areas of the warm sea. As they died, microscopic organisms fell to the bottom, forming a dense layer. Some areas are rich in deposits of such sediments, hundreds of meters or more in thickness. The most famous chalk hills are:

• Volga region;
• French;
• English.

Studying Cretaceous rocks, scientists find traces in them:

• sea ​​urchins;
• shellfish;
• sponge

As a rule, these inclusions are only a few percent of the total volume of explored chalk, so such components do not affect the parameters of the rock. Having studied the Cretaceous deposits, the geologist receives information about:

• age of the breed;
• thicker than the water that was here before;
• special conditions that previously existed in the study area.

Igneous rocks

Magmatism is usually understood as a set of phenomena caused by magma and its activity. Magma is a silicate melt, naturally present in a liquid form close to fire. Magma contains a high percentage of volatile elements. In some cases there are types:

• non-silicate;
• low silicate.

When magma cools and crystallizes, igneous rocks appear. They are also called igneous.

Breeds are distinguished:

• intrusive;
• effective.

The first are formed at great depth, and the second - during an eruption, that is, directly on the surface of the planet.

Often the magma contains a variety of rocks that have melted and mixed with the silicate mass. This is caused by:

• an increase in temperature in the earth's thickness;
• pressurized;
• a combination of factors.

The classic version of igneous rock is granite. Its very name in Latin - “fire”, reflects the fact that the rock in its original state was extremely hot. Granite is highly valued not only due to its technical parameters(this material is incredibly durable), but also because of the beauty provided by the crystal inclusions.