I-II
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Part I 7
1. Our Earth 7
2. The Nature of Rocks 9
3. Mineral 12
4. Hardness 13
5. Rock-forming Minerals 13
6. Mineralogy 16
7. Mineral Deposits 18
8. Geology 18
9. Geophysics 19
10. Geochemistry 21
11. Igneous Rocks 22
12. Intrusion 25
13. Sedimentary Rocks 26
14. Metamorphic Rocks 29
15. Rock Cycle 32
16. Vein 34
17. Groundwater 34
18. Erosion 35
19. Weathering 37
20. Ore 37
21. Volcanology - the Study of Volcanoes 38
22. Alexander Karpinsky 40
Part II 41
1. Apatite 41
2. Granite 41
3. Pegmatite 42
4. Clay 42
5. Shale 43
6. Quartz 43
7. Chalcedony 45
8. Sand 46
9. Sandstone 46
10. Limestone 47
11. Marble 47
12. Chalk 48
13. Calcite 48
14. Stalactite and Stalagmite 49
15. Salt 50
16. Halite 51
17. Gypsum 51
18. Selenite 52
19. Alabaster 52
20. Basalt 53
21. Gold 53
22. Petroleum 55
23. A.Y. Fersman 56
Part III 57
1. PJSC Apatit 57
2. Geological and Mining Engineering 57
3. Mining 57
4. Mining Operations 58
5. Prospecting, Exploration and Sampling 60
6. Mining Equipment 62
7. Mine Tubs and Cars in Britain 63
8. Conveyers 64
9. Rock Pressure 65
10. Principles of Mining Methods 67
11. Mining Geodesy 70
12. Underground Surveying for Details 72
13. Types of Locomotives Used Underground 73
14. Opencast Workings 73
15. Coal Mining 75
16. Coal Mining Waste 78
17. Clean Coal Technology 79
18. Metal Mining 79
19. Gem Cutting 81
20. Production of Synthetic Fuels 83
21. Mine Safety 86
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, I II - 090200 , 090500 , 090300 .
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PART I
Text 1. OUR EARTH
The earth is a huge, slightly lopsided ball of rock, so enormous that we can scarcely imagine how heavy it is; it weighs about 6,600,000,000,000,000,000,000 tons. Its diameter through the equator is 7,926,68 miles, but from pole to pole the diameter is 7,899,98 miles, or 26,7 miles less. In spite of this very small flattening, and an even smaller bulge in the southern hemisphere, the earth is still nearly a perfect sphere.
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When geologists talk of the earth as a ball of rock, they do not mean it is solidly made up of the stones you see on a rocky beach. Scientists actually know very little about the rocks deep inside the earth, and even the definition of a rock itself may seem vague and complicated. It is easy to define chemical elements and the minerals they form, but it is not easy to define the rocks of which the earth is made.
All life is, as we know, spread out in a thin layer on, or close to the surface of the rocky earth. Some plants and animals make their homes two or three miles above the sea level. Others can survive an equal depth below the surface of the sea. But it is within this thin six-mile layer, that over 99,99 per cent of all plants and animals live, grow, and die.
The story of where rocks came from is closely related to
the origin of the earth, and this mystery is yet to be unraveled. The best guess is that the earth and the entire solar system have been in existence for a little over four billion years.
Astronomers get a fairly good idea of the chemical composition of the universe by studying the light from the stars and the sun. But as soon as scientists have to deal with the smaller, colder bodies like the planets and satellites, information is more difficult to obtain. Our direct knowledge of rocks is limited very much to the crust of our earth. The deepest hole that man has ever been able to dig in it is an oil well that goes more than 9 km deep. This is only about five miles down, a mere pinprick into the crust.
Scientists can measure the age of rocks that contain uranium quite accurately. Uranium in a rock slowly but steadily decays into one kind of lead. Thus, careful measurements to find the relative weight of uranium and lead in the rock can be used to measure the rocks age. When about one quarter of the uranium has changed to lead, two billion years have passed. This is almost the age of the oldest known rocks, found in the mountains of India.
In recent years, astronomers and geologists have shown that the story of the origin of the world is very complicated. Yet everyone agrees that the earth, the planets and the sun are made of matter. Therefore, comprehension what is meant by matter is the first step in understanding rocks.
Matter is anything which occupies space, has weight and can be detected by some means or another. Each bit of matter on the earth or in the universe attracts all other bits of matter. This ever present attraction is known as gravity or gravitation.
All matter is made of 105 chemical elements listed in the Mendeleyevs Periodic Table. Over 99 per cent of the material in the earth is made of about 30 lightest elements. All our rocks are also made of these 30 light elements. If the sun and the other stars are included, the two lightest elements - hydrogen and helium - make up nearly all of the matter in the universe.
On the hot surface of the sun, most atoms (the smallest particles of an element) are independent of each other. On the earth atoms usually combine to form molecules. Sometimes two or more atoms of the same kind will join together. Atoms of hydrogen and oxygen are usually joined in pairs. More often, two or more different elements unite, forming a molecule made of several kinds of atoms.
The hundred or more kinds of atoms can combine in millions of different ways. In each case a different molecule is formed. Living things contain large, complex molecules. Nearly all of them include atoms of carbon joined with atoms of hydrogen, oxygen, nitrogen, sulfur and phosphorus. In the crust of the earth 30 or so lightest elements have joined together to make thousands upon thousands of different molecules. These molecules form chemicals which occur naturally in the crust of the earth. When these natural chemicals have a definite crystal structure and are not formed in or by living things, they are then called minerals.
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Thousands of kinds of minerals are known, but only a hundred or so are common. These common kinds are made mainly of eight elements: oxygen, silicon, aluminium, iron, calcium, sodium, potassium and magnesium. These eight elements, joined together in various ways, make up nearly 99 per cent of the crust or outer part of the earth.
One important group of minerals in the earths crust are the oxides. Here, the molecule is made of one or more atoms of oxygen combined with one or more other elements. Best known and most important of all the oxides is silicon dioxide, the chemical name for quartz or sand. Quartz is the most widespread mineral that is found in the earths crust.
Another common group of minerals are the silicates. Here silicon and oxygen are once again combined. But in addition, one or more metals such as aluminium, calcium, sodium or potassium are part of the molecule. Silicates are the most important group of rock-forming minerals. Whether in the form of silicon dioxide or in the form of silicates, the two elements - silicon and oxygen - together make up 83 per cent of the crust of the earth. Six metals make up 16 per cent; other elements add up to one per cent. Iron, the most important metal, is in the less-than-one per cent group; so are all the precious metals. All of these together are the materials comprising the earths crust.
(4700)
NOTES:
flattening - , ;
potassium - .
Text 2. THE NATURE OF ROCKS
To the geologist, rock is the natural, solid material that makes up the earth. The first word, natural, immediately eliminates man-made materials like cement, glass, brick, and steel, even though these all come from the crust of the earth.
The second word, solid, rules out the air and other gases, the oceans, rivers, lakes, and other liquids. However, solids can be changed to liquids and gases by being heated; liquids and gases can be changed into solid by being cooled. The definition of a rock means solid at temperatures which normally occur in the earths crust. Even this does not cover everything, because one of the most common chemical compounds on the surface of the earth may or may not be a rock, depending on its temperature. This chemical compound is water H2O. Water makes up nearly three fourths of the surface of the earth. Most of it is in the form of a liquid, and while liquid water affects the rocks of the earth in many ways, water is not a rock. However, in the arctic and antarctic regions, and in the temperate regions during winter, millions upon millions of tons of water are a hard, frozen solid. In the Antarctic, ice occurs in layers nearly two miles thick. Ice is, therefore, a rock, and geologists study the great ice fields just as they study other rock formations.
In speaking of rocks, geologists use the word solid in its technical sense. A solid is the matter that is not a liquid or gas. What the geologists would sometimes call solid rockmight seem strange to you. The wet sands on the beach and the shifting sands in the desert are a solid and a rock. This is also true of the layers of mud and muck in the swamps, or the ash and cinders from volcanoes. They are rock also.
The third word, material, brings no additional problems to the definition of a rock. But it may be well to point out that the materials in the crust of the earth may have two distinct origins: organic and inorganic. Most of the material in the crust of the earth is inorganic. This means that it is in no way related to life or living things. Lava pouring from a volcano makes an excellent example of inorganic material. So do the great masses of granite pushed miles into the air.
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While most of the rocks are made of materials which are not or ever have been alive, some rocks are organic made up by living things. Coal and oil deposits, for example, are the remains of ancient plants. Oil, you might say, is a liquid and therefore is not a rock. However, there are no great underground lakes of oil as some people imagine. The oil is usually soaked up in the pores of sand and other rocks. Under special conditions it drains into wells from where it is pumped to the surface. Millions of gallons of oil are locked up in rocks, especially in the oil shales. Asphalt is another organic rock.
Less well-known are the rocks which have been formed from the remains of sea animals. Shells cemented together form several kinds of limestone. Sometimes these are the shells of microscopic animals, sometimes they are much larger shells.
Coral is another kind of rock made by living things. Coral animals take lime from the sea water and build it into reefs in which millions upon millions of coral animals live. Islands of coral dot the South Pacific. A few microscopic plants and sponges have silica skeletons. Under certain conditions these, too, form organic rocks.
One final explanation, and the definition of rocks is about as complete as it can be. The definition implies that rocks are large masses of natural, solid material, big enough to form a distinct part of the earths crust.
Diamonds are not rocks, even though they are found in the crust of the earth. But if a whole mountain of diamonds was discovered, then it would be correct to call diamonds a rock. There are places where one can see mountains of marble, quartz granite or limestone. You can find large beds of coal, shale or lava. These are rocks. There are the many miles of rich soil, more miles of sand in the desert and on the shores. They all make up major parts of the earths crust, so they are called rocks.
You may have noticed that the definition of a rock does not say anything about minerals. This is odd, for we commonly think of rocks and minerals as going hand in hand. Most often they do. However, all minerals are inorganic. They are chemical compounds and therefore have a definite chemical composition. Mixtures of minerals often do form enough of the earths crust to be considered rocks. Granite, made mainly of three minerals mica, feldspar and quartz, is undoubtedly a rock.
There are also times when a single mineral may form a rock. Quartz is a common mineral. Some forms of sandstone are made up of 99 per cent pure quartz. In this and other cases the rock and the mineral are made of the same chemical substances. This may also happen in the case of the mineral, calcite, which forms a kind of pure marble. Here again the rock and the mineral are the same. Gypsum is another rock made of a single mineral. The mineral kaolin makes fine clay and forms still another kind of rock.
However, rocks may be of materials which are not minerals at all. Volcanic glass or obsidian is not a mineral but it frequently forms rocks. Coal, peat and asphalt are not minerals but they are rocks.
In spite of the difficulty in defining rocks, most rocks are easily recognized when you see them, and most are made of minerals or mineral-like substances. They are usually solid, hard, and heavy, compared to the other materials you see and use daily.
The study of rocks is petrology. It is a difficult science, for most rocks are harder to identify than birds, flowers or trees. But the study of rocks is important, for rocks and minerals yield the materials that make modern civilization possible. The rock which forms soil is the basis for life on land. Dissolved minerals taken from the rocks by running water make the sea salty and make ocean life possible to exist.
The identification of rocks is easy when the rocks are made of minerals and when the minerals are large enough to be identified. When the rock is fine-grained and when the minerals all look alike, as they do in some of the dark rocks, it takes skill to identify them. The geologist will often cut a piece of rock with a diamond saw and polish one surface until it is perfectly smooth. He then cements the smooth surface to a glass slide, and polishes the rest of the rock until it is paper thin. This thin layer of rock is examined under a microscope, using polaroid light. As the light passes through the minerals in the rock, it is altered, producing beautiful colors. These colors depend on the kind of minerals and on the angle at which the crystals have been cut. Such patterns aid much in the process of identification.
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The identification of rocks involves much more properties. The texture, color, hardness and relative weight of the rock can also be used as clues. The geologist also looks for the geologic structures in which the rock occurs. Certain rocks are found only in volcanoes, others in caves. Still others are more likely to be found in valleys than on high ridges.
(5880)
NOTES:
shifting sands - ;
to soak - ();
feldspar - ;
ridge - , , .
Text 3. MINERAL
Mineral, in general, is any naturally occurring chemical element or compound, but in mineralogy and geology, chemical elements and compounds that have been formed through inorganic processes. Petroleum and coal, which are formed by the decomposition of organic matter, are not minerals in the strict sense. More than 3000 mineral species are known, most of which are characterized by definite chemical composition, crystalline structure, and physical properties. They are classified primarily by chemical composition, crystal class, hardness, and appearance (color, luster, and opacity). Mineral species are, as a rule, limited to solid substances, the only liquids being metallic mercury and water. All the rocks forming the earths crust consist of minerals. Metalliferous minerals of economic value, which are mined for their metals, are known as ores.
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NOTES:
compound - , , ;
luster - ;
opacity - .
Text 4. HARDNESS
Hardness is an ability of a solid substance to resist surface deformation or abrasion. Various interpretations, depending on the usage, are applied to the term. In mineralogy, hardness is defined as the resistance of the smooth surface of a mineral to scratching. A soft surface is scratched more easily than a hard surface; thus a hard mineral, such as diamond, will scratch a soft mineral, such as graphite, and the hard mineral will not be scratched by the soft. The relative hardness of minerals is determined according to the Mohs scale of hardness. In the Mohs scale, named for the German mineralogist Friedrich Mohs who devised it, ten common minerals are arranged in order of increasing hardness and are assigned numbers: 1) talc; 2) gypsum; 3) calcite; 4) fluorite; 5) apatite; 6) orthoclase (feldspar); 7) quartz; 8) topaz; 9) corundum; and 10) diamond. The hardness of a mineral specimen is obtained by determining which mineral in the Mohs scale will scratch the specimen. Thus, galena, which has a hardness of 2.5, can scratch gypsum and can be scratched by calcite. The hardness of a mineral largely determines its durability.
In metallurgy and engineering, hardness is determined by impressing a small ball or cone of a hard material on the surface to be tested and measuring the size of the indentation. Hard metals are indented less than soft metals. This test to determine the hardness of metal surfaces is known as the Brinell test, named after the Swedish engineer Johann Brinell, who invented the Brinell machine for measuring the hardness of metals and alloys.
Hardness is related to the strength, durability, and toughness of solid substances, and in common usage the term is often extended to include those properties.
(1460)
NOTES:
* feldspar - ;
* galena - , ;
* durability - .
