TEST 2 - Variant 1

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TEST 2

READING

Variant 1

I. Read the text and match the headings (1-4) with the paragraphs (A-D).

1 The most malleable of all the metals

2 An essential component for photographic film

3 Finding of a new metal

4 The discovery caused human deaths

PRECIOUS METALS

А When Christopher Columbus discovered the Americans in 1492, Spanish expeditions soon followed, and though they are much criticised for their cruelty, greed and treachery, the military achievements of the ‗Conquistadors‘ were remarkable. First they conquered Mexico and took away its valuable treasures. Seeking more land and wealth they invaded Peru, home of the Incas. Here they murdered the king and stole his vast hoard of gold - probably the greatest in the world. The natives were enslaved and set to work to win more gold. Later the Spanish conquered Chile and Bolivia, both of these countries being rich in precious metals, particularly silver.

B To the metallurgists, the most exciting discovery made by the Spaniards was the finding of platinum in the silver mines of Mexico. At that time the new metal was regarded as more of a nuisance than of value. It could not be melted by any known method, though it was possible to make a very realistic imitation of gold from it. Later it joined the group of precious metals and is now used for jewelry and in industry.

C Gold is the most malleable of all the metals. It can be hammered into sheets so thin that 250 of them would equal the thickness of a sheet of paper. It is also the most ductile metal. One gram of gold can be drawn into a wire 1.8 miles in length. Gold is the least chemically active of all metals and does not combine with oxygen to form rust. This ability to resist corrosion makes it very durable, i.e. it may last for centuries. Pure gold is too soft to be used in jewelry so it is usually alloyed with other metals. The proportion of gold in an alloy is measured in karats. Pure gold is 24 karats. A 14 karat gold ring is an alloy of about 58% of gold and small percentages of copper and silver.

D Silver is similar to gold in many ways. Like gold, it is very malleable and ductile and so it is also used for jewelry. Silver differs from gold in that it is more reactive and tarnished when exposed to the traces of sulfur in the air. Pure silver is too soft and so it is usually alloyed with copper to increase its hardness and durability. Silver is used for coins and for photographic film because certain compounds of silver, such as silver bromide, reflect light. Silver is the best conductor of electricity known.

Abridged from: English. Correspondence Course. Student’s book, TPUPublishing House, 2014.

II. Read the text about mining. Write whether the following statements are true

(T) or false (F).

Statement

True

False

1) The term ―mining‖ includes the recovery of oil and gas from wells as coal, iron ores and other useful minerals from the earth.

2) There are only two mining methods.

3) The problem of depth also affects the mining method.

4) If the rock containing the metallic substance is at a deep site, it is massive.

5) Mine workings vary only in shape.

6) Depending on their function mine workings are described as exploratory or productive.

MINING

Mining refers to ore extraction. Mining is the industrial process of removing a mineral-bearing substance from the place of its natural occurrence in the Earth‘s crust. The term ―mining‖ includes the recovery of oil and gas from wells; metal, non- metallic minerals, coal, peat, oil shale and other hydrocarbons from the earth.

Mining can be done either as a surface operation (quarries, opencasts or open pits) or by an underground method. The mode of occurrence of the sought-for metallic substance governs to a large degree the type of mining that is practiced. The problem of depth also affects the mining method. If the rock containing the metallic substance is at a shallow site and is massive, it may be economically excavated by a pit or quarry-like opening on the surface. If the metal-bearing mass is tabular, as a bed or vein, and goes to a great distance beneath the surface, then it will be worked by some method of underground mining. Working or exploiting the deposit means the extraction of mineral. Mine workings vary in shape, dimensions, location and function.

Depending on their function, mine workings are described as exploratory to find or prove mineral, and productive when used for the immediate extraction of useful mineral. Productive mining can be divided into capital investment work, development work, and face or production work. Investment work aims at ensuring access to the deposit from the surface. Development work prepares for the face work, and mineral is extracted (or produced) in bulk.

Abriged from: Abridged from: Barakova M.Ya., Zhuravleva R.I. English for mining engineers. Moscow, 2001.

III. Read the text below and answer the questions.

1. What are two major hypotheses for the origin of gold within the Witwatersrand basin?

2 What century do these hypotheses date back to? 3 What is the palaeoplacer theory?

4 When is the synsedimentary theory?

5 What are the key arguments in favor of a placer origin?

6 Why are the principal arguments for a hydrothermal origin?

Witwatersrand Conglomerate Gold Genesis Theories

There are two major hypotheses for the origin of gold within the Witwatersrand basin - the ―placer‖ model and the ―hydrothermal‖ model. Both concepts date back more than 100 years. Determining which of these theories is correct not only concerns earth scientists, but it also has great economic significance for mining companies. The exploratory strategies for gold within the Witwatersrand basin and other parts of the world are continually being modified according to current scientific models.

Theories of Genesis

They are: (1) palaeoplacer theory- developed either by normal placer-forming mechanisms, or by precipitation of gold in suitable environments; (2) synsedimentary theory - conglomerates were merely the porous sediments within which gold and sulfides were deposited from hydrothermal solutions derived either from a magmatic source or from dehydration of the West Rand Group shales.

(1) The key arguments in favor of a placer origin are the strong spatial correlation between gold, uraninite, and detrital zircon, and the intimate relationship between the heavy minerals and the sedimentary structures and environment. Another point is the equal intensity of mineralisation in porous conglomerates and less porous pyritic quartzites. The main drawback is a mineralogical one: the very small particle size of the gold, its hackly shape, and low fineness (i.e. high % Ag) (more typical of hydrothermal deposits) the presence of pyrite, uraninite, and the absence of black sands typical of modern placers. Another major problem is the source of the large quantity of gold and uranium in the basin, far more than is likely to have been derived from any Archaean greenstone belt, certainly more than from the most productive South African greenstone belt, Barberton. While it is certain that greenstone belts were part of the source area, it seems likely that the gold and uranium could also have been derived from altered granites.

(2) The principal arguments for a hydrothermal origin are that the gold is crystalline, sometimes replaces pebbles, may be contained within and replace pyrite that has replaced pebbles, and is associated with a suite of hydrothermal ore minerals and alteration products (sericite and chlorite) typical of hydrothermal orebodies the world over. Nowadays, the modified placer theory emphasizes the control on the occurrence of ore minerals by placer-forming mechanisms, as well as, some modification by metamorphism.

Abridged from: Introduction into Mineral Exploration - edited by Charles J. Moon, Micheal K.G. Whateley and Anthony M. Evans; Blackwell Publishing – 2006.

VOCABULARY AND TERMINOLOGY

IV. Read the text Witwatersrand Conglomerate Gold Genesis Theories in detail and match the English word-combinations (1-10) with the Russian equivalents (A-J).

1 greenstone belt

a продукт изменения, разрушения или разложения

2 magnetic response

b механизмы нормального формирования прииска

3 hydrothermal solutions

c золотой прииск, россыпь

4 be restricted (v)

d осадочные комплексы, последовательности осадконакопления

5 normal placer-forming mechanisms

e быть ограниченным

6 placer deposits

f магнитная восприимчивость

7 pyritic quartzite

g диоритовый пояс

8 sedimentary sequence

h структурные остатки

9 structural remnants

i гидротермальные растворы

10 alteration product

j пиритовый кварцит

V. For questions 1–6, choose one of the words (a-f) that best completes a gap in the text.

lead

ferrous

radioactive

base

handle

valuable

Types of Metals

Mining for metals is a major part of the mining industry. There are four types of metals. (1) metals are one type. These metals contain iron. For example, stainless steel is a ferrous metal. (2) metals are a second type of metal. (3) and copper are base metals. Unlike base metals, precious metals are not very common. Precious metals are typically very (4) . Silver, gold and platinum are precious metals. The final type of metal is (5) metals. Radioactive metals can be dangerous. For this reason, miners should (6) radioactive metals like uranium carefully.

Abridged from: Virginia Evans, Jenny Dooley, Kenneth Rodgers. Career Paths: Natural Resources II — Mining (Student’s Book). Express Publishing, 2014

VI. Fill in the gaps with the given derivatives.

fossilized fossils fossilize fossilization fossiliferous

1. Heavy mining equipment and dynamite was used to blast away overlying strata to uncover the rock layers in the cliff face.

2. Jellyfish have such soft bodies, it's rare that they become .

3. Skin and soft tissues rot down quickly before takes place.

4. The book is far more than a mere description of sedimentary indicators of facies and of as tracers of environment.

5. He collected plant specimens both living and .

6. Nevertheless, the fossil record of cephalopod eggs is scant since their soft, gelatinous eggs decompose quickly and have little chance .

VII. Complete the summary of the text Witwatersrand Conglomerate Gold Genesis Theories. Use only one word in each sentence.

1. There are two major for the origin of gold within the Witwatersrand basin.

2. Due to current scientific models, the exploratory strategies are continually being .

3. The palaeoplacer theory is developed either by normal mechanisms, or by precipitation of gold in suitable environments.

4. The synsedimentary theory claims that were merely the porous sediments within which gold and sulfides were deposited.

5. One of the points in favor of this theory is the equal intensity of in porous conglomerates.

6. The main drawbacks are the very small particle size of the gold, its hackly shape, and low fineness, the presence of pyrite, uraninite, and the of black sands.

7. Another problem is the of the large quantity of gold and uranium in the basin.

8. One of the arguments for a hydrothermal origin is that the gold is associated with a suite of hydrothermal ore minerals and products.

VIII. Match the term (1-10) with the definition (A-J).

1 dimension

A the existence or presence of something

2 precipitation

B a group of minerals, rocks, or fossils occurring together and characteristic of a location or period.

3 occurrence

C water that falls from the clouds towards the ground, especially as rain or snow

4 placer

D a measurement of something in a particular direction, especially its height, length, or width

5 fluvial

E a facies typified by the minerals characteristic of greenschists, thought to result from metamorphism at

moderate temperature and pressure.

6 fossilization

F a deposit of sand or gravel in the bed of a river or lake, containing particles of valuable minerals.

7 greenschist facies

G a place, typically a large, deep pit, from which stone or other materials are or have been extracted.

8 alluvial

H the process of becoming a fossil (= something preserved in rock for a very long period)

9 suite

I relating to or derived from alluvium.

10 quarry

J of or found in a river.

GRAMMAR

IX. Use the verbs in brackets in the required form.

1. If we (to be able) to see the molecules in a bottle of oxygen gas, we should be surprised by the chaos and confusion.

2. Provided a piece of radium (to be brought) near a charged electroscope, the leaves will come together, thus showing the loss of charge.

3. If we not (to raise) temperature, the pressure would not increase.

4. If we had time enough, we (to repeat) our experiment.

5. If we (to solve) the problem of controlled thermonuclear reactions, we could use oceans of fuels.

X. Rewrite each conditional sentence of type 1 to form conditionals of type 2 and 3.

Example: If I am not too busy, I shall go to the concert. (type I)

If I were not too busy, I should go to the concert. (type II)

If I had not been too busy, I should have gone go to the concert. (type III)

1. They will all be surprised if I make such a mistake.

2. If he doesn‘t come in time, shall we have to wait for him?

3. If no one comes to help, we shall be . obliged to do the work ourselves.

4. If you put on your glasses, you will see better.

5. What shall we do if they are late?

6. Will he be very displeased if I don‘t ring him up?

TRANSLATION

XI. Translate the following conditional sentences into Russian.

1. If the sun got its energy from ordinary chemical processes, such as the burning of coal and oil, it wouldn't last for more than several thousand years.

2. If one were to examine the stars on a clear, moonless night, he would soon discover that not all the visible stars are of the same degree and brightness.

3. If you look at the horizon immediately after sunset, you will often see a very bright star, Venus.

4. If it were possible to live on the moon, people would be able to jump about six times as high as they could on the earth.

5. The volume of gas will be proportional to its absolute temperature provided its pressure remains constant.

6. If there were no atmosphere, the surface of the earth would become very, very hot by day and too cold at night.

7. If the contact opens and closes very quickly, the amount of arcing will be greatly reduced.

8. Travellers will probably have to take a reserve of oxygen with them, if they fly to Venus.

WRITING

XII. Write an abstract (100-120 words) to the following article. (For more details you may see Writing Reference p. 192)

Electrical Methods

Mineral deposits and geologic structures may be mapped by their reaction to electrical and electromagnetic fields. These are produced by either direct or alternating current, except where ore bodies spontaneously furnish their own electrical field (self-potential methods). Electrical energy may be supplied to the ground by contact or by induction. Three main groups of electrical methods may be distinguished: (1) self-potential, (2) surface-potential, and (3) electromagnetic methods. Frequently the first two groups are combined into one group of potential methods; the electromagnetic methods are usually subdivided into galvanic- electromagnetic and inductive-electromagnetic.

Self-potential method. The self-potential method is the only electrical method in which a natural field is observed; its causes are spontaneous electrochemical phenomena. These phenomena occur on ore bodies and on metallic minerals and placers; they are produced by corrosion of pipe lines and on formation boundaries in wells by differences in the conductivity of drilling fluid and formation waters. Ore bodies whose ends are composed of materials of different solution pressure and are in contact with solutions of different ion concentration, act as wet cells and produce an electrical field which can be detected by surveying equipotential lines or potential profiles. For the mapping of equipotential lines, a high-resistance milliammeter is connected to two unpolarizable electrodes are used. One is kept stationary and the other is moved until the current vanishes. At that point the electrodes are on an equipotential line.

When a source of electrical energy is grounded at two points, an electrical field is produced. Distortions of this field result from the presence of bodies of different conductivity; good conductors will attract the lines of flux, and vice versa. As it is difficult to survey these lines of flux, lines of equal potential, that is, lines along which no current flows, are mapped instead. In practice power is supplied to two grounded electrodes from an alternating current generator.

Resistivity methods.

Equipotential-line methods, while useful for the mapping of vertical or steeply dipping geologic bodies, are not suited to the investigation of horizontally stratified ground. Conversely, resistivity methods are applicable to depth determinations of horizontal strata and the mapping of dipping formations.

In resistivity procedures not only the potential difference between two points but also the current in the primary circuit is observed. The ratio of potential difference and current, multiplied by a factor depending on electrode spacing, gives the resistivity of the ground.

Potential-drop-ratio methods. The essential feature of the resistivity methods is a determination of the potential difference between two points at the surface and a measurement of the current in the external circuit. In potential-drop-ratio methods current measurements in the external circuit are not made and the potential drops in two successive ground intervals (represented by three stakes arranged in a straight line, radiating from one of the power electrodes) are compared. The potential-drop- ratio method is best suited for the location of vertical formation boundaries (faults, dikes, veins, and the like).

Electromagnetic-galvanic methods. Electromagnetic methods of electrical prospecting differ from potential methods in that the electromagnetic field of ground currents and not their surface potential (electric field) is measured. They fall into two major groups: (1) electromagnetic-―galvanic‖ methods in which the primary energy is supplied by contact as in the potential methods; (2) electromagnetic-―inductive‖ methods in which the ground is energized by inductive coupling (with insulated loops). To supply electrical energy to the ground by contact, line electrodes are laid out at right angles to the strike, point electrodes parallel with the strike.

Electromagnetic-inductive methods. In inductive procedures power is supplied to the ground by insulated loops which will cause induction currents to flow in subsurface conductive bodies. An advantage of inductive methods is the ease with which power may be transferred into the ground when the surface formations are poor conductors. Since currents induced in the subsurface conductors are dependent on frequency, interpretative advantages may be gained by regulating the frequency.

Abridged from C.A. Heiland. Geophysical Exploration. New York, 1968