What does basalt look like? Basalt
/ Rock Basalt
Basalt is a rock of volcanic origin, formed in the form of basaltic lavas. Chemical mineralogy considers basalt rocks as effusive, natural stones identical to gabbro. The color range of basalt is not very wide, but it has a distinctive black color. The structure of basalt is considered as fine-grained, in some cases glassy. The upper part of basaltic lavas may have some swellings, which were formed during the evaporation of water and gaseous elements from molten magma. Some minerals can accumulate in these swellings, including calcite, prehnite, native copper, and others. As a result of such formations, amygdaloidal basalts can be formed. Individual elements of basalt rocks are so small that they can only be seen through a microscope. Sometimes there are basalts with a porous structure, which makes it possible to consider clearly visible crystalline elements in them. Visible crystals include porphyrated phenocrysts, which are formed from plagioclase or augitome. Basalt deposits look like lava flows that formed during a volcanic eruption. The main effusive rock of the normal series, the most common of all cainotype rocks. The main minerals of phenocrysts are clinopyroxene and calcium plagioclase (N 30-90), sometimes olivine, orthopyroxene; the groundmass is composed of the same minerals (without olivine) and magnetite in glass (or without it). This mineral became basalt from the Latin basaltes, basanites, from the Greek. basanos - touchstone; according to another version, they became basalts from the Ethiopians. basal is an iron-bearing stone. Varieties can be distinguished according to the features of the mineral composition (apatite, graphite, diallag, magnetite, etc.), the composition of minerals (anorthite, labradorite, etc.), the features of the structure and (or) texture, chemical composition (ferruginous, ferrobasalts, calcareous, alkaline - calcareous, etc.). Yoder and Tilley (Yoder and Tilley, 1962) suggested using the nepheline-olivine-diopside-quartz tetrahedron for classification. The activity of silica in the melt is controlled mainly by reactions of the type: These reactions can be divided into 3 groups: Belonging to these groups is determined by the chemical composition of the rock, by the presence of the corresponding normative minerals in the results of petrochemical recalculation using the CIPW method. According to the geodynamic setting, the main types are distinguished: They are usually dark gray, black or greenish-black rocks with a glassy, cryptocrystalline aphyric or porphyritic structure. In porphyritic varieties, small phenocrysts of greenish-yellow isometric olivine crystals, light-colored plagioclase, or black pyroxene prisms are clearly visible against the background of the general cryptocrystalline mass. The size of phenocrysts can reach several centimeters in length and make up to 20-25% of the rock mass. The texture in basalts can be dense massive, porous, amygdaloidal. Tonsils are usually filled with quartz, chalcedony, calcite, chlorite and other secondary minerals - such basalt is called mandelstein. The ground mass is often not crystallized. Aphyric (without porphyritic phenocrysts) varieties are frequent. Basalt flows are characterized by columnar separation. It occurs as a result of uneven cooling of the rock. Marine basalts are often cushion-like. It is formed as a result of the rapid cooling of the surface of the lava flow by water. The incoming magma lifts the formed shell, flows out from under it and forms the next pillow. Basalt is the most common effusive rock on Earth, and on other planets as well. The main mass in basalt is formed in the mid-ocean ridges and forms the oceanic crust. In addition, basalts are typical of settings for active continental margins, rifting, and within-slab magmatism. During the crystallization of basaltic magma at a depth, strongly differentiated, layered intrusions (such as Norilsk, Bushveld and many others) are usually formed. They are composed of various rocks, the sequence of crystallization of which is determined by the dynamics of magma crystallization. First, the highest-temperature minerals crystallize from the melt, and they precipitate to the bottom of the magma chamber. in this case, the melt is enriched in some components and depleted in others. With a decrease in temperature, a change in crystallizing minerals occurs. Layered massifs contain deposits of copper-nickel ores, chromites and platinoids. Basalts are formed during partial melting of typical mantle rocks - lherzolites, harzburgites, wehrlites, etc. The composition of the melt is determined by the chemical and mineral composition of the protolith, the physicochemical conditions of melting, the degree of melting, and the mechanisms of melting. Basalts are very easily altered by hydrothermal processes. At the same time, plagioclase is replaced by sericite, olivine by serpentine, the groundmass is chloritized and, as a result, the rock acquires a greenish or bluish color. The basalts that pour out at the bottom of the seas change especially intensively. They actively interact with water, while many components are removed and deposited from them. This process has great importance for the geochemical balance of some elements. So most of the manganese enters the ocean in this way. Interaction with water radically changes the composition of marine basalt. This influence can be estimated and used to reconstruct the conditions of ancient oceans from basalts. During metamorphism in basalt, depending on the conditions, it turns into green shales, amphibolites and other metamorphic rocks. During the metamorphism of basalts at significant pressures, they turn into blue shales, and at high temperatures and pressures into eclogites consisting of pyrope and sodium clinopyroxene - omphacite. Basalt is used as a raw material for crushed stone, the production of basalt fiber (for the production of heat and sound insulating materials), stone casting and acid-resistant powder, as well as a filler for concrete. Basalt is highly weather resistant and therefore often used for exterior finish buildings and for making outdoor sculptures. Basalt is a natural rock found near volcanoes. Basalt mineral looks like plates or round stones. The color of basalt is dark gray or black, and sometimes there are green shades, which indicates its secondary change. This crystalline natural mineral occupies considerable areas at the bottom of the world's seas and oceans, as well as thousands of square kilometers on land. Basalt is mainly formed from small grains of plagioclase, magnetite and other natural minerals. This breed is distributed on all continents of our planet. There are basalt deposits mainly in mountainous areas. The color range of basalts ranges from gray, sometimes with a green tint, to almost black. The mineral composition of stone from different deposits can differ significantly from each other. Each country produces different types basalts, which are used in various areas of our life. Basalt is a product of crystallization of the main basaltic magma, which rises to the very top from the bowels of the earth along deep faults and volcanic craters. The deposit of basalt mineral significantly affects the state of its surface. The bubbly surface is formed during the cooling of the lava, steam and gas escape through these holes. Various minerals are deposited in the voids: copper, calcium and zeolite. This strong rock is used in construction, and it is also a raw material for casting, which is called stone. The mineral is used as an acid-resistant material in the chemical and other industries. different countries world - for the manufacture of special fittings and pipes that will not be subject to acid attack and destruction by aggressive reagents. Exist different kinds this rock. Depending on the hardness and strength, they are used in different areas of our life. Crushed stone from basalt is added to concrete, covered with railroad tracks, used when laying asphalt. The powdered mineral is added to reinforced products, from which earthquake-resistant structures are built. This rock is indispensable as a heater in the construction of houses. Since it is a natural material, the walls of buildings will also breathe during operation. Basalt is used to decorate facades and buildings inside in the same way as marble. They make columns, arches from it, line the walls of buildings inside and out. For finishing floors and fireplaces are made ceramic tiles obtained by casting from basalt rocks. A strong and elastic thread can be obtained from the mineral, clothes are made from it that are very durable and do not burn, tennis rackets. Basalt is also used for the manufacture of special cardboard, which is resistant to high temperatures and is able not to ignite even at temperatures up to a thousand degrees. Basalt is used in various industries and areas. Advantages of a natural mineral. It has many advantages, the most significant are: Gray basalt mineral, hunted in mine springs and quarries. Basalt is mined by companies associated with the mining industry. The mineral, after withdrawal, is sent in batches to manufacturing plants that will produce a variety of products:Name history
Classifications
Petrochemical classification
2(Mg,Fe)SiO3 -> (Mg,Fe)2SiO4 + SiO2 (orthopyroxene = olivine + silica)
NaAlSi3O8 -> NaAlSiO4 + SiO2 (albite = nepheline + silica)Geodynamic classification
Composition and structure
Prevalence
Origin
Analogues
Changes
Metamorphism
Metamorphic rocks with a composition close to basalts are called metabasites.Application of basalt
How basalt deposits of these valuable rocks are formed
Where is basalt used
Application of basalt
Catalog of Minerals
It is traditionally believed that the word "basalt" comes from the Greek "basis" ("base"). "Basal" in the modern sense means "lower". Therefore, basalt is the base rock; the stone upon which all things rest...Another version is also interesting. In one of the African dialects, the word "basal" means "boiling". Basalt, according to the Ethiopians, is a mineral that first boiled in the mouth of a volcano, and only then poured onto the surface of the Earth.
The version, in general, is not too far from the truth. Basalt stone shows the properties of volcanic rock as often as the qualities of the base material of continental plates. It is widely distributed on the planet, but is found mostly in places of noticeable volcanic activity.
Basalt deposits
Beautiful young basalts are easily found in the vicinity of the Kamchatka and Kuril volcanoes. Black and black with green rocks of Vesuvius and Etna are extremely good. Dark gray, almost black basalt erupts in Hawaii.There are many different basalts in India: the Hindustan tectonic plate, crashing (and continuing to crash deeper and deeper) into the Eurasian plate, like a bulldozer knife, raked sedimentary deposits into a pile (Himalayan mountains) and twisted out layers of the lower, basal rock.
Australian basalts are valued by scientists: on this continent (and one more cliff in Canada), basalt monoliths have been preserved that “saw” our planet as hot and not yet very round.
decorative properties basalt of West African origin are considered the most outstanding. Mauritanian varieties of stone are famous for their dark green background and original color blotches. And although such basalt is somewhat less frost-resistant than its smooth-colored counterparts, the demand for it as a building material has not decreased for several centuries.
The smoky shade of gray basalt from China is called "twilight". It is used for both finishing works, and for paving roads, construction of various structures. Chinese and Siberian basalts are recognized as the most durable and resistant to destructive atmospheric influences.
Basalt - weathered?
Basalt and granite are the most durable of stones, but they are also powerless before prolonged weathering. Difficult chemical composition basalt is “responsive” to changes in precipitation acidity.Moisture absorption is stronger than more quantity gases were released during the eruption of volcanic basalt - leads to the destruction of the strongest rock by ice crystals.
Basalt is exposed to abrasive wear. The streams of water and the wind carrying the sand gradually wear down the outer layers of the rock. However, for the complete destruction of some basalts, it takes more time than our planet exists.
Bubbly basalt - hardened lava foam
To foam such a heavy rock (the density of basalt sometimes exceeds 3.3 grams per cubic centimeter), it is necessary to pre-saturate the molten stone with vapors and gases. Not all areas of pronounced volcanic activity can "boast" of a similar composition of erupted basalts.However, where gas-saturated basalts hit the Earth's surface, mineralogists and gemologists find crystalline geodes and colored layers in cavities. In most cases, almond-stone basalt (this is the name of the rock similar to Swiss cheese) gives the seekers the most beautiful agates, crystallized, geologically interesting compounds of calcium and copper.
Application of basalt
Basalt stone melts when heated to a temperature of 1250˚С, and when molten, it is easy to mold. cast basalt products popular with both builders and decorators. But basalt wool is in the greatest demand. Assembled in mats, it is a reliable, durable, heat-insulating and noise-absorbing material resistant to external influences.Basalt crumb is not only a bulk additive to asphalt and concrete. The dielectric properties of basalt make it possible to use the crushed mineral as a backfill for high-voltage converters.
High resistance basalt to aggressive environments makes it possible to manufacture chemical production apparatuses and acid-resistant powders from natural stone.
The aesthetic properties of basalt make it possible to create small and large-scale sculptural groups, interior and jewelry decorations from a strict and solemn stone. The use of basalt as an expressive architectural material expands the possibilities of artistic rethinking of space.
Basalt Jewelry
Basalt black goes well with the soft sheen of silver. Jewelry sets made of intricately faceted tropical night-colored basalt are worn as pretentious additions to evening dresses.Finds its use and light basalt. Beads, bracelets, necklaces and belts made of polished basalt figurines make amazing sets.
Basalt pillars - natural curiosities
The volcanic origin of basalt led to the formation of curious formations - correctly cut stone pillars. Basalt magma, frozen in the vent of the volcano, eventually cracks along several vertical planes.As a result of the erosion exposure of the magma shaft, the basalt massifs are subjected to intense weathering, which first leads to the appearance of huge "clusters" of stone pillars of a geometrically perfect shape. Even edges can give a basalt monolith the appearance of a four-, five-, six-, and even seven-sided rod of many meters in length.
The history of construction describes cases of using basalt pillars in the construction of capital buildings.
The average chemical composition of basalt according to P. Daly (%): SiO 2 - 49.06; TiO 2 - 1.36; Al 2 O 3 - 15.70; Fe 2 O 3 - 5.38; FeO - 6.37; MgO - 6.17; CaO - 8.95; Na 2 O - 3.11; K 2 O - 1.52; MnO - 0.31; P2O5 - 0.45; H 2 O - 1.62. The content of SiO 2 in basalt ranges from 44 to 53.5%. According to the chemical and mineral composition, olivine unsaturated with silica (SiO 2 about 45%) basalts and olivine-free or slightly saturated with silica (SiO 2 about 50%) tholeiitic basalts are distinguished.
The physical and mechanical properties of basalt are very different, which is explained by different porosity. Basalt magmas, having low viscosity, are easily mobile and are characterized by a variety of occurrence forms (covers, flows, dikes, reservoir deposits). Basalt is characterized by columnar, less often spherical separation. Olivine basalts are known at the bottom of the oceans, oceanic islands (Hawaii), and are widely developed in folded belts. Tholeiitic basalts occupy vast areas on platforms (trap formations of Siberia, South America, and India). Deposits of ores of iron, nickel, platinum, and Icelandic spar (Siberia) are associated with rocks of the trap formation. A deposit of native copper is known in the amygdaloidal basalt porphyrites of the Lake Superior region in the USA.
The density of basalt is 2520-2970 kg/m³. Porosity ratio 0.6-19%, water absorption 0.15-10.2%, compressive strength 60-400 MPa, abrasion 1-20 kg/m², melting point 1100-1250°C, sometimes up to 1450°C, specific heat capacity 0.84 J/kg K at 0°C, Young's modulus (6.2-11.3) 104 MPa, shear modulus (2.75-3.46) 104 MPa, Poisson's ratio 0.20-0, 25. The high strength of basalt and the relatively low melting point led to its use as a building stone and raw material for stone casting and mineral wool. Basalt is widely used to obtain crushed stone, road (side and paving stones) and facing stones, acid-resistant and alkali-resistant material. Industry requirements for the quality of basalt as a raw material for crushed stone are the same as for other igneous rocks. For the production of mineral wool, basalt is usually used in blending. It has been established that the melting temperature of raw materials should not exceed 1500°C, and the chemical composition of the melt is regulated by the following limits (%): SiO 2 - 34-45, Al 2 O 3 - 12-18, FeO up to 10, CaO - 22-30, MgO - 8-14, MnO - 1-3. Basalt stone casting materials have great chemical resistance, hardness and abrasion resistance, high dielectricity and are used in the form of floor and cladding slabs, pipeline linings, cyclones, as well as various insulators.
The physical and mechanical properties of basalts and andesite-basalts are very heterogeneous. This is due to the diversity of the mineral composition, structure and texture of the rocks. Thus, microcrystalline basalts have a specific gravity of up to 3.3 T/m3, a bulk density of up to 3.0 T/m3, and a compressive strength of up to 5000 kg/cm2, while in porous basalts, the compressive strength can be less than 200 kg/m3. cm2. Ancient paleotype effusive rocks are also characterized by high variability in strength and deformation properties, but in general they have higher values of these indicators. This is explained by the crystallization of volcanic glass, the filling of pores with secondary minerals, and other postmagmatic transformations of erupted rocks. Interesting data on the relationship between the strength of andesite-basalts and their composition, structure and porosity are given by N.V. Ovsyannikov, which shows that the strength of andesite-basalts significantly depends on the mineralogical composition.
Olivine varieties have the greatest strength, and augite varieties have the least. Equally important is the structure of the breed. Andesite-basalts of the same composition with a vitrophyric groundmass structure have a significantly lower strength than rocks with an intersertal structure. Studies by V. M. Ladygin and L. V. Shaumyan made it possible to establish that basalts of different petrochemical composition and structure have different physical and mechanical properties. The most durable are massive unaltered porphyritic basalts with microdiabase and microdolerite structure. Their average strength is 2000 kg/cm2, reaching in some cases 2800 kg/cm2 with a bulk density of 2.80 G/cm3. The dynamic modulus of elasticity of rocks in the massif is on average 690 103 kg/cm2. In amygdaloidal basalts, the influence of the structural and mineralogical features of the rock is offset by the presence of amygdales, the content of which reaches 15–30%. They are characterized by relatively low values of strength (1200 kg/cm2), elastic modulus (480 103 kg/cm2) and bulk density (2.66 G/cm3). It has been established that an increase in the content of denitrified glass to 10-15% reduces the strength of basalts by 10-20%, the presence of tonsils in the amount of 10-20% has the same effect. In weathered rock varieties, the strength decreases sharply. The degree of weathering of basalt rocks and the thickness of the weathering crust generally depend on their age and climatic conditions.
Basalt - an analogue of gabbro - is the most common outflowing rock; depending on the formation conditions, it has a glassy or cryptocrystalline structure. The color of basalt is dark gray to black. In terms of physical and mechanical parameters, basalt is similar to gabbro, and even surpasses it in strength (Lf reaches 500 MPa). Basalts are very hard but brittle rocks, making them difficult to work with.
Application of basalt
Practical use basalt building materials made from this stone are widely used in construction, because they are inherent in: resistance to abrasion, to the influence of alkalis and acids, excellent thermal insulation and sound absorption, strength, heat resistance and fire resistance, high dielectricity, durability, vapor permeability and, what is not less important, environmental friendliness.
This mineral is used as a building stone, for the production of mineral wool, a filler for concrete and stone casting. Road and facing stones are also made from it, crushed stone and acid-resistant powder are obtained. Facing plates on this moment simultaneously with a decorative purpose, they perform the function of insulators. Thanks to its resistance to weathering, basalt is well suited for finishing the exterior of buildings, as well as for casting street sculptures.
The production of basalt and products based on it is most often the production of basalt is a mining industry. In special quarries and mines, stone is mined, on the basis of which various products are subsequently produced. In the form of basalt fiber, this mineral is used for insulation of buildings and roofs, in three-layer sandwich panels, insulation of low-temperature equipment units during nitrogen extraction and creation of oxygen columns, for heat and sound insulation of pipelines, stoves, fireplaces and other braziers, power units and in general buildings and structures for any purpose. Basalt in molten form is used to create stairs, shaped tiles and other building materials. Arbitrary shapes are cast from it, including battery stands, as well as insulators for voltage networks. different sizes. Powder from such material is used for the production of pressed reinforced products.
Common types of basalt differ from each other in various indicators, primarily such as color and structure. The most famous brand is a variety called "Basaltina". This is a material of Italian origin, which is mined near the capital of this country and has been used mainly for architectural purposes since ancient rome. Its strength is comparable to that of granite, and its decorative qualities are comparable to those of limestone. The stone after laying retains the saturation of the color palette for a long time. Therefore, its cost often exceeds the price of other brands by more than twice.
Another variety is Asian. It is distinguished by a dark gray color and a reasonable price. It is widely used for design and architectural purposes.
Moorish green basalt has a rich dark green hue, with various inclusions present in it, which give the stone an original appearance while maintaining all physical and mechanical characteristics. Only the criteria for hardness and frost resistance are somewhat lower.
Twilight basalt is brought from China. It has a smoky gray or black color. It is recognized as the strongest and wear-resistant and frost-resistant among all varieties of this mineral. It is well protected from adverse weather conditions.
The most famous basalt products are: basalt-based insulation, basalt finishing tiles, basalt chimneys for fireplaces and stoves.
Graphs
Fig.8 Lunar basalt: diagram
"Debye temperature of a chemical element (Q) - Concentration factor (K k)"
Fig.9 Lunar basalt: diagram
"Debye temperature of a chemical element (Q) - Content of a chemical element (C)"
Fig.10 Basalt: diagram
"Mass of an atom of a chemical element (M) - Content of a chemical element (C)"
Fig.11 Lunar basalt: diagram
"Mass of an atom of a chemical element (M) - Concentration coefficient (K k)"
Fig.12 Lunar basalt: diagram
"Distance to the inert gas of the chemical element (e) - Concentration factor (K k)"
Fig.13 Lunar basalt: diagram
"Distance to the inert gas of the chemical element (e) - Content of the chemical element (C)"
Annex A
Annex B
LITERATURE
1. Bondarenko S.V. Geochemical features of Lower Proterozoic quartzites in the central part of the South Pechenga zone. / S.V. Bondarenko, V.A. Shatrov, V.I. Sirotin // Geology and geoecology: studies of the young. Proceedings of the XVI Conference of Young Scientists, dedicated to the memory of Corresponding Member. K.O. Briefly. Ed. acad. Mitrofanova F.P. - Apatity, 2005. - 426 p.
2. Gumirov Sh.Sh. Simulation of the process of solid-phase diffusion. /Collect.abs. participation 15 Ross. conf. "Youth, Science, Culture". - Obninsk: DNTO Intellect of the Future, 2000. - p.112-113.
3. Gumirov Sh.V. Participation of the atomic impulse in biochemistry, coalification, mineragenesis. / Sh.V. Gumirov – Science-intensive technologies for the development and use of mineral resources: Sat. scientific articles / Sib. state industry un-t; under the general editorship. V.N.Fryanova. - Novokuznetsk, 2014. - p. 345-355.
4. Gumirov Sh.V. Modeling of solid-phase diffusion of elements to explain their differentiation in the lithosphere and ore genesis. - Natural and technical sciences, No. 1, 2008. - p. 183-188.
5. Gumirov Sh.V. Fundamentals of the theory of adaptation of inanimate objects and adaptive analysis in geology. /Sh.V. Gumirov - Novokuznetsk, SMI, 1993. - 409 p.
6. Gumirov Sh.V. Modeling of the process of solid-phase diffusion of chemical elements to explain their differentiation in the lithosphere. / Sh.V.Gumirov, Sh.Sh. Gumirov // Bulletin of the Russian Academy of Natural Sciences (West Siberian Branch) Issue 5. Kemerovo, 2002 - P. 273-282.
7. Konilov A.N. Petrology of "Frozen veins" in eclogites of the White Sea province on the Kola Peninsula. / A.N. Konilov, A.A. Shchipansky. // Physical and chemical factors of petro- and ore genesis: new frontiers. Mat. conf. dedicated 110 years old. D.S. Korzhinsky. - M., 2009.- p. 198-203.
8. Lazko E.M. Thermobarogeochemistry and prediction of postmagmatic mineralization. / EAT. Lazko et al. // Thermobarochemical studies of mineral formation processes. - Novosibirsk: Nauka, 1988. - S. 136 - 149.
9. Medvedev V.Ya. Influence of shock decompression on the distribution of LIL - and HFS-elements in pyropes from kimberlites. / V.Ya. Medvedev, K.N. Egorov, L.A. Ivanova // Physical and chemical factors of petro- and ore genesis: new frontiers. Mat. conf. dedicated 110 years old. D.S. Korzhinsky. - M., 2009.- p. 269-271.
10. Ovchinnikov L.N. Formation of ore deposits. / L.N. Ovchinnikov - M.: Nedra, 1988. - 255 p.
11. Rundkvist D.V. General principles construction of geological and genetic models of ore formations. T.1. / D.V. Rundkvist - Novosibirsk: Nauka, 1983. - S. 14 - 26.
12. Anand M. Petrology and geochemistry of LaPaz Icefield 02205: A new unique low-Ti mare-basalt meteorite. / M. Anand, Lawrence A. Taylor, Christine Floss, Clive R. Neal, Kentaro Terada, Shiho Tanikawa.
Basalt is a very popular stone, which is found everywhere not only in the CIS countries, but also abroad. Regardless, most people don't know what basalt is. This article will provide an answer to this question.
Basalt is an igneous rock. Has the main composition. The name comes from the Ethiopian "basal" - boiled, which means "a stone containing iron." Found in nature in the form of stones various shapes or lava flow.
Most often it has a dark gray, black or greenish-black color. It is in green that basalt is most often found in the photo. The structure is also different. glassy, cryptocrystalline aphyric and porphyritic. In the case of a porphyritic structure, one can notice inclusions of crystals of greenish-yellow olivine, light-colored plagioclase or pyroxenes that have the form of black prisms. Inclusions make up from 15% to 30% of the mass of igneous rock. The size of the phenocrysts is several centimeters in length.
Stones can have a dense, massive, almond-like and porous texture. Tonsils can be filled with calcite, chlorite, plagioclase and other minerals. Stones with tonsils are called mandelsteins.
The stone stands out for its unique properties. Among the stones, it is considered the most elastic and plastic. It stretches well, which allows it to be used in the manufacture of things of small sizes.
The melting point of the stone fluctuates 100 to 1500 degrees Celsius. This melting point allows it to withstand extreme temperature fluctuations.
Considering its strength, resistance to shock and temperature changes, one can understand why it is so often used in the design of public spaces and on the street.
How and where is basalt formed?
The main method of stone formation is solidification of magma erupted from the lower layers of the earth. Silicate igneous melt of basalt composition is also taken into account. The origin of magma itself comes from the rocks of the Earth's mantle. The type of the resulting basalt is determined by the composition of the initial substance (rock) from which it is formed. And also this is influenced by the conditions under which it melts and the mechanism of melt escape.
Basalt is an igneous rock found on much of the Earth and other planets. Almost the entire oceanic crust of the planet Earth consists of it. Deposits of this stone are formed in the form of traps - structures that look like stairs. These traps are located on 150,000 square kilometers of the Yenisei and Lena river basins. And also the stone is mined in eastern Siberia.
In addition to the CIS countries, it is mined in America, Brazil, Greenland, Iceland and Australia. Among foreign countries, India is considered the richest in deposits of this stone.
Extraction of stone is carried out in mines and quarries. The mined basalt is sent to enterprises engaged in the manufacture of things using this stone.
Scope of stone use
The areas of application are many. This stone is very common due to the fact that it has great features:
One of the main areas of application of basalt is architectural construction. Thanks to good technical specifications It can be used for building cladding and interior decoration. The characteristics make it possible to install basalt products even in open areas under the influence of external negative factors.
It can also be used in construction. For example, to create high-quality building materials and insulation. In addition, its strength is sufficient to build columns and arches out of it. In the production of reinforced structures, basalt powder is added to the product to increase its strength and reliability.
Basalt is a stone that is very popular both in construction and architecture. In addition, there are a huge number of photos of basalt in interior decoration that speak of its popularity in design art.
Basalt stone
BASALT (Latin basaltes, basanites, from Greek basanos - touchstone; according to another version, from Ethiopian basal - iron-bearing stone * English basalt, basaltic rocks; German Basalt; French basalte; Spanish basalto) - erupted Cenotype , the effusive analogue of . The color of basalt is dark to black. It consists mainly of the main, monoclinic, and accessory minerals -, etc. The structures of basalt are intersertal, aphyric, less often hyalopilitic, textures are massive or porous, amygdalolithic. Depending on the grain size, they distinguish: the most coarse-grained -, fine-grained - anamesite, fine-grained - basalt proper. Paleotype analogues of basalt -.
The chemical composition of basalt
The average chemical composition of basalt according to P. Daly (%): SiO 2 - 49.06; TiO 2 - 1.36; Al 2 O 3 - 15.70; Fe 2 O 3 - 5.38; FeO - 6.37; MgO - 6.17; CaO - 8.95; Na 2 O - 3.11; K 2 O - 1.52; MnO - 0.31; P2O5 - 0.45; H 2 O - 1.62. The content of SiO 2 in basalt ranges from 44 to 53.5%. According to the chemical and mineral composition, olivine unsaturated with silica (SiO 2 about 45%) basalts and olivine-free or slightly saturated with silica (SiO 2 about 50%) tholeiitic basalts are distinguished.
Physical properties of basalt
The physical and mechanical properties of basalt are very different, which is explained by different porosity. Basalt magmas, having low viscosity, are easily mobile and are characterized by a variety of occurrence forms (, flows, reservoir deposits). Basalt is characterized by columnar, less often spherical separation. Olivine basalts are known at the bottom of the oceans, oceanic islands (Hawaii), and are widely developed in folded belts. Tholeiitic basalts occupy vast areas in (formations of Siberia,). Ore deposits are associated with rocks of the trap formation, (Siberia). A deposit is known in amygdaloidal basaltic porphyrites of the Upper Lake region.
Density of basalt
Basalt 2520-2970 kg/m³. Porosity ratio 0.6-19%, water absorption 0.15-10.2%, compressive strength 60-400 MPa, abrasion 1-20 kg/m², melting point 1100-1250°C, sometimes up to 1450°C, specific heat capacity 0.84 J/kg.K at 0°C, Young's modulus (6.2-11.3).10 4 MPa, shear modulus (2.75-3.46).10 4 MPa, Poisson's ratio 0.20 -0.25. The high strength of basalt and relatively low melting point led to its use as a building stone and raw material for stone casting and mineral wool.
Application of basalt
The use of basalt - basalt is widely used for the production of road (side and paving stones) and facing stones, acid-resistant and alkali-resistant material. Industry requirements for the quality of basalt as a raw material for crushed stone are the same as for other igneous rocks. For the production of mineral wool, basalt is usually used in blending. It has been established that the melting temperature of raw materials should not exceed 1500°C, and the chemical composition of the melt is regulated by the following limits (%): SiO 2 - 34-45, Al 2 O 3 - 12-18, FeO up to 10, CaO - 22-30, MgO - 8-14, MnO - 1-3. Basalt stone casting materials have great chemical and abrasion resistance, high dielectricity, and are used in the form of floor and cladding slabs, pipeline linings, cyclones, and various insulators.
B 50 have been explored for crushed stone with industrial reserves of 40 million m³. Two basalt deposits with industrial reserves of 6.5 million m³ have been explored facing stone( , ). The annual production of basalt is over 3 million m³. In the CCCP, basalt deposits are concentrated mainly in Armenia, Eastern Siberia and the Far East. Basalt covers in the eastern regions of the United States form large deposits in the states of New York, New Jersey, Pennsylvania, Connecticut (the largest stone crushing plants).
