Text 22. ALEXANDER KARPINSKY
Alexander Karpinsky is an outstanding Russian scientist who described the geological past of the European part of our country including the Donetz Basin. This tireless scholar studied the past history of the earth in order to help people to explore its wealth. He founded the Russian school of geology, which has won the leading position in the world science. His “Essays on the Geological History of European Russia” was of great importance in the development of geology and coal-mining in the Donetz Basin.
Alexander Karpinsky followed M. V. Lomonosov’s idea that rocks and minerals undergo constant changes, and that there are continuous physico-chemical processes in the earth’s crust.
He personally drew up paleogeographicalmaps showing the distribution of land and sea at prehistoric times. These geographical maps afforded a graphic picture of European Russia 500, 300, 250 and 200 million years ago.
According to his theory an enormous sea covered nearly the entire territory from the Urals to the Caspian and the Black Sea, and as far as the present Baltic Republics.
The territory of the present Donbass was once a bay of this sea. Giant plants and trees grew on its shores. These plants and trees fell into the marsh of the bay and were covered by sand and silt. The compressed deposits of trees and other plants underwent decomposition, and deposits of coal were formed.
(1160)
PART II
Text 1. APATITE
Apatite (Greek apate, "deception"), is a mineral so named because it resembles various other minerals for which it might be mistaken. It consists chiefly of phosphate of lime. Apatite is a distinct mineral of composition Ca5(PO4)3F in which some or all of the fluorine may be replaced by chlorine (chlorapatite). The mineral crystallizes in the hexagonal system and has a hardness of 5 and a specific gravity of 3.2. When pure, apatite is colorless and transparent, but it may exhibit various degrees of color and opacity. These mineral phosphates of lime were often used in the preparation of fertilizers, but they have been replaced by phosphate rock.
(550)
Text 2. GRANITE
Granite, igneous rock of visible crystalline formation and texture, is composed of feldspar (usually potash feldspar and oligoclase) and quartz, with a small amount of mica (biotite or muscovite) and minor accessory minerals, such as zircon, apatite, magnetite, ilmenite, and sphene. Granite is usually whitish or gray with a speckled appearance caused by the darker crystals. Potash feldspar imparts a red or flesh color to the rock. Granite crystallizes from magma that cools slowly, deep below the earth’s surface. Exceptionally slow rates of cooling give rise to a very coarse-grained variety called pegmatite. Granite, along with other crystalline rocks, constitutes the foundation of the continental masses, and it is the most common intrusive rock exposed at the earth’s surface.
The specific gravity of granite ranges from 2.63 to 2.75. Its crushing strength is from 1050 to 14,000 kg per sq cm (15,000 to 20,000 lb per sq in). Granite has greater strength than sandstone, limestone, and marble and is correspondingly more difficult to quarry. It is an important building stone, the best grades being extremely resistant to weathering.
(970)
NOTES:
· potash feldspar - калиевый полевой шпат;
· sphene – титанит.
Text 3. PEGMATITE
Pegmatite is a variety of extremely coarse-grained igneous rock chemically similar to and closely associated with granite. The mineral constituents of pegmatite are largely those typical of acidic intrusive rocks: orthoclase feldspar, quartz, and mica. Individual mineral crystals may be up to several meters (tens of feet) in length. The growth of crystals this large indicates that the parent magma, from which the rock solidified, was able to cool very slowly, after injection into fissures extending outward from a central magma chamber. Pegmatite is widely distributed in the crust of the earth but is found especially in older mountain chains, where it is restricted essentially to those surface areas in which igneous and metamorphic rocks are prevalent. Minerals containing the elements boron, beryllium, and lithium are abundant in some pegmatites. Other pegmatites contain commercial quantities of the feldspar, mica, and gem-grade tourmaline.
(820)
NOTES:
· boron – (хим.) бор;
· tourmaline – турмалин.
Text 4. CLAY
Clay is earth or soil that is plastic and tenacious when moist and that becomes permanently hard when baked or fired. Of widespread importance in industry, clays consist of a group of hydrous alumino-silicate minerals formed by the weathering of feldspathic rocks, such as granite. Individual mineral grains are microscopic in size and shaped like flakes. This makes their aggregate surface area much greater than their thickness and allows them to take up large amounts of water by adhesion, giving them plasticity and causing some varieties to swell. Common clay is a mixture of kaolin, or china clay (hydrated clay), and the fine powder of some feldspathic mineral that is anhydrous (without water) and not decomposed. Clays vary in plasticity, all being more or less malleable and capable of being molded into any form when moistened with water. The plastic clays are used for making pottery of all kinds, bricks and tiles, tobacco pipes, firebricks, and other products. The commoner varieties of clay and clay rocks are china clay, or kaolin; pipe clay, similar to kaolin, but containing a larger percentage of silica; potter’s clay, not as pure as pipe clay; sculptor’s clay, or modeling clay, a fine potter’s clay, sometimes mixed with fine sand; brick clay, an admixture of clay and sand with some ferruginous (iron-containing) matter; fire clay, containing little or no lime, alkaline earth, or iron (which act as fluxes), and hence infusible or highly refractory; shale; loam; and marl.
(1260)
NOTES:
· adhesion – прилипание, адгезия, молекулярное притяжение, связность породы;
· malleable – тягучий, ковкий;
· loam - суглинок, глина и песок с перегноем, формовочная глина;
· marl - мергель, рухляк, известковая глина, нечистый известняк.
Text 5. SHALE
Shale is a common name applied to fine-grained varieties of sedimentary rock formed by the consolidation of beds of clay or mud. Most shales exhibit fine laminations that are parallel to the bedding plane and along which the rock breaks in an irregular, curving fracture. Shales are usually composed of mica and clay minerals, but the grains are so fine that the rock seems to have a homogeneous appearance, and individual minerals cannot be identified without the aid of a microscope. Most varieties of shale are colored in various shades of gray, but other colors, such as red, pink, green, brown, and black, are often present. Shales are soft enough to be scratched with a knife and feel smooth and almost greasy to the touch. All gradations in consistency exist between shales and clay; true shales differ from clays in their lack of plasticity in water. Many shales yield oil when distilled by heat, and the sedimentary rocks containing larger quantities of oil are called oil shales. Widely distributed throughout the world, oil shales are a source of oil for countries lacking petroleum.
(920)
Text 6. QUARTZ
Quartz is the second most common of all minerals, composed of silicon dioxide, or silica, SiO2. It is distributed all over the world as a constituent of rocks and in the form of pure deposits. It is an essential constituent of igneous rocks such as granite, rhyolite, and pegmatite, which contain an excess of silica. In metamorphic rocks, it is a major constituent of the various forms of gneiss and schist; the metamorphic rock quartzite is composed almost entirely of quartz. Quartz forms veins and nodules in sedimentary rock, principally limestone. Sandstone, a sedimentary rock, is composed mainly of quartz. Many widespread veins of quartz deposited in rock fissures form the matrix for many valuable minerals. Precious metals, such as gold, are found in sufficient quantity in quartz veins to warrant the mining of quartz to recover the precious mineral. Quartz is also the primary constituent of sand.
Properties. Quartz crystallizes in the rhombohedral system. The size of the crystals varies from specimens weighing a metric ton to minute particles that sparkle in rock surfaces. Quartz is also common in massive forms, which contain particles ranging in size from coarse-grained to cryptocrystalline (grains invisible to the naked eye but observable under a microscope). The mineral has a hardness of 7 and specific gravity of 2.65. The luster in some specimens is vitreous; in others it is greasy or splendent (shining glossily). Some specimens are transparent; others are translucent. In the pure form, the mineral is colorless, but it is commonly colored by impurities.
Quartz crystals exhibit a property called the piezoelectric effect, that is, they produce an electric voltage when subjected to pressure along certain directions of the crystal. Because of this property, quartz crystal has important applications in the electronics industry for controlling the frequency of radio waves. It also has the optical property of rotating the plane of polarized light and is used in polarizing microscopes.
Varieties. The coarsely crystalline varieties of quartz are, in general, transparent and lustrous. Rock crystal, a colorless form of quartz, usually occurs in distinct crystals. Rose quartz is coarsely crystalline but without distinct crystal form and is colored rose red or pink, the color often fading on exposure to light. Smoky quartz occurs in crystals ranging from smoky yellow to dark brown. Amethyst is colored purple or violet. Many other minerals form inclusions in crystalline varieties of quartz. Rutilated quartz contains fine needles of rutile that penetrate crystals of colorless quartz. Aventurine is a variety of quartz containing brilliant scales of hematite or mica. Liquids and gases also occur as inclusions in quartz. Milky quartz owes its milky-white color to the presence of numerous minute liquid or gaseous inclusions.
Uses. The different forms of chalcedony and many of the crystalline varieties of quartz are used as gemstones and other ornamental materials. Pure rock crystal is used in optical and electronic equipment. In the form of sand, quartz is used extensively in the manufacture of glass and silica brick, and is also used in cement and mortar. Ground quartz is used as an abrasive in stonecutting, sandblasting, and glass grinding. Powdered quartz is used in making porcelain, scouring soaps, sandpaper, and wood fillers. Large amounts of quartz are used as a flux in smelting operations. Almost all natural high-grade quartz crystal, which is an important raw material in the electronics industry, is imported from Brazil, the only country with large deposits of the mineral in commercial quantities. Quartz crystals can also be made synthetically.
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NOTES:
· silica – кварц, кремнезем;
· transparent - прозрачный;
· translucent - просвечивающий, полупрозрачный.
Text 7. CHALCEDONY
Chalcedony is a mineral, a cryptocrystalline variety of quartz of various shades of white, gray, yellow, brown, green, and blue. Like quartz it has the formula SiO2, a hardness of 7, and a specific gravity of 2.65. Although it is usually translucent, some of the milk-white varieties are opaque. The color variations occur as the result of the presence of such impurities as iron, aluminum, and nickel. Chalcedony occurs as a lining or filling of cavities in rocks. The principal varieties are agate, which is banded and striped, having alternating layers of chalcedony and opal; jasper, or other forms of quartz; carnelian, which is clear and of various shades of red; chrysoprase, an apple green variety, in which the color is due to nickel oxide; heliotrope or bloodstone, of a dark green color, with small spots of jasper; onyx, consisting of bands of opal and chalcedony of different colors, usually black and white; plasma, of a deep green color; and sardonyx, a red-and-white-banded variety of chalcedony.
The many colors and the high luster that chalcedony takes by polishing render it valuable for brooches, necklaces, and other ornaments, and some varieties are cut as sealstones. Chalcedony is found in many parts of the world; superior varieties prized for gems are mined in Uruguay and in the Lake Superior area of the United States and Canada.
(1140)
NOTES:
· translucent – просвечивающий, полупрозрачный;
· jasper – яшма.
Text 8. SAND
Sand is loose, incoherent mass of mineral materials in a finely granular condition, usually consisting of quartz (silica), with a small proportion of mica, feldspar, magnetite, and other resistant minerals. It is the product of the chemical and mechanical disintegration of rocks under the influences of weathering and abrasion erosion. When freshly formed the particles are usually angular and sharply pointed, becoming smaller and more rounded by attrition by the wind or by water.
Sand is an important constituent of most soils and is extremely abundant as a surface deposit along the courses of rivers, on the shores of lakes and the sea, and in arid regions.
One specific form of sand is the major ingredient in glassmaking. Other types of sand are used in foundries to make casting molds and in ceramics, plasters, and cements. Sand is used as a grinding and polishing abrasive in the form of sandpaper, which is a sheet of paper covered on one side with sand or a similar abrasive substance. Sandblasting is an important technique used for cleaning stone or for smoothing rough metal surfaces by blowing a stream of sand under air or steam pressure.
(970)
Text 9. SANDSTONE
Sandstone is a coarse-grained, sedimentary rock consisting of consolidated masses of sand deposited by moving water or by wind. The chemical constitution of sandstone is the same as that of sand; the rock is thus composed essentially of quartz. The cementing material that binds together the grains of sand is usually composed of silica, calcium carbonate, or iron oxide. The color of the rock is often determined largely by the cementing material, iron oxides causing a red or reddish-brown sandstone, and the other materials producing white, yellowish, or grayish sandstone. When sandstone breaks, the cement is fractured and the individual grains remain whole, thus giving the surfaces a granular appearance. Sandstones of various geologic ages and of commercial importance are widely distributed in the U.S.A. and Europe. Besides serving as a natural reservoir for deposits of oil and gas, sandstone is used in building flagstone pavings and in the manufacture of whetstones and grindstones.
(850)
NOTES:
· whetstone – точильный камень;
· grindstone – шлифовальный камень.
Text 10. LIMESTONE
Limestone is a common type of sedimentary rock composed principally of calcite (calcium carbonate, CaCO3). When "burned" or calcined (raised to a high temperature), it yields lime. Crystalline metamorphosed limestone is known as marble. Many varieties of limestone are formed by the consolidation of seashells, which are formed by the largely CaCO3 secretions of various marine animals. Chalk is a variety of porous, fine-grained limestone composed mostly of foraminifera shells; coquina is a soft limestone made up of shell fragments. A variety of the rock, known as oolitic limestone, is composed of small spherical concretions, each containing a nucleus of a sand grain or other foreign particle around which deposition has taken place.
(640)
NOTES:
· coquina - ракушечник;
· oolitic limestone - оолитовый известняк.
Text 11. MARBLE
Marble is a crystalline, compact variety of metamorphosed limestone, consisting primarily of calcite (CaCO3), dolomite (CaMg (CO3)2), or a combination of both minerals. Pure calcite is white, but mineral impurities add color in variegated patterns. Hematite, for example, adds red; limonite, yellow; serpentine, green; and diopside, blue. Marble is capable of taking a high polish and is used principally for statuary and for building purposes. Extensive deposits are located in Italy, Great Britain, and in the United States. Commercially the term marble is extended to include any rock composed of calcium carbonate that takes a polish, and it includes some ordinary limestones. The term is further extended in the loose designation of stones such as alabaster, serpentine, and sometimes granite.
The surface of marble crumbles readily when exposed to a moist, acid atmosphere, but marble is durable in a dry atmosphere and when protected from rain. The purest form of marble is statuary marble, which is white with visible crystalline structure. The distinctive luster of statuary marble is caused by light penetrating a short distance into the stone and then being reflected from the surfaces of inner crystals. The most famous variety of statuary marble is the Pentelic marble of Greece, found in the quarries of Mount Pentelikon in Attica. Pentelic marble was used by the great sculptors of ancient Greece, including Phidias and Praxiteles, and it was used to make the Elgin marbles. Parian marble, also used by ancient Greek sculptors and architects, was quarried chiefly at Mount Parpessa on the Grecian island of Paros. Carrara marble - which occurs abundantly in the Apuan Alps of Italy and is quarried in the region of Carrara, Massa, and Serravezza - was used in Rome for architectural purposes in the time of Augustus, the first emperor, but the finer varieties of sculptural marble were discovered later. The greatest works of Michelangelo are made of this marble, and it is used extensively by present-day sculptors.
(1720)
Text 12. CHALK
Chalk is a soft white or whitish form of limestone, composed of the remains of small marine organisms such as foraminifera and coccolithophores; it formed after the shells and skeletons of these organisms were deposited in a thick layer on the sea bottom. Chemically, chalk is almost pure calcium carbonate with traces of other minerals. It ranges in hardness and texture from very soft porous varieties to harder close-grained types. Chalk is particularly common in strata of the Cretaceous period (Latin creta, "chalk"). Large deposits are found in the United States, and in the British Isles. Cretaceous chalk is exposed in the White Cliffs of Dover on either side of the English Channel.
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Text 13. CALCITE
Calcite is a mineral consisting largely of calcium carbonate (CaCO3). Next to quartz, it is the most abundant of the earth’s minerals. Crystallizing in the hexagonal system, calcite is noted for its wide variety of crystalline forms. It also occurs in massive or cryptocrystalline formations. For example, crystalline variety of calcite - Iceland spar - is the only pure form of calcite found in nature. Limestone, chalk, travertine, Oriental alabaster, and marble are among the most common of the massive forms of the mineral. Calcite is also found as stalactites and calcareous tufas, forms deposited by mineral waters.
Colorless, with a hardness of 3 and a specific gravity of 2.72, pure calcite is readily identified by the ease with which it is cut or cleaved and by the rapidity with which it reacts with dilute acids. Such contaminants as magnesium, ferrous iron, manganese, and zinc will alter the properties of the mineral in varying degrees, depending on the amounts present.
(830)
NOTES:
· calcareous tufa – известковый туф;
· manganese – марганец.