156770

Metamorphic rocks

20. Употребите данные в скобках глаголы в соответствующей времен ной форме:

1.There (to be) three main groups of rocks, namely, sedimen tary, igneous and metamorphic rocks.

2.These rocks (to make up) the crust of the Earth.

3.Sedimentary rocks (to be divided) into: mechanical sediments — gravel, sand, sandstone, shale, etc; chemical sediments — rock salt, gypsum, ironstones, etc; organic sediments — peat, coal, etc.

4.The particles of consolidated rocks (to be cemented) firmly to

one another.

5.Gypsum (to be formed) through sedimentation of mineral substances that (to be dissolved) in water.

6.It is quite obvious that the textures of igneous rocks (to vary) accord ing to the depth at which rocks (to be formed) many years ago.

7.Exposed igneous rocks (to be formed) at various depths.

21. Переведите предложения, обращая внимание на значение местоимения either я союза either ... or.

1.Metamorphic rocks have been derived either from igneous or from sedimentary rocks.

2.Sediments are formed either at the surface or near the sur face of the Earth by the action of heat, water and the remains of organisms.

Unit 4

_____________________________________________________

97

3.Mechanical sediments can be either consolidated or unconsolidated.

4.Igneous rocks are formed as extrusive or as intrusive masses solidified either at the surface of the Earth's crust or deep under ground.

5.Either of these rocks are very important because they are of ten rich in mineral deposits.

22. Переведите предложения, используя следующие слом и сочетания слов.(Обратитевниманиена времяи залогглагола-сказуемого.)

to consist (of), to be used as fuel, to be dissolv ed, substance, fuel, as is known, by the action of, to be form ed, the Earth's crust, sedim entation

1.Земная кора состоит из осадочных, изверженных и ме таморфических пород.

2.Осадочные породы образуются под действием воды, тепла, холода и органических веществ.

3.Как известно, каменная соль образуется путем осажде ния минеральных веществ. Эти вещества растворяются в воде.

4.Уголь используется в качестве топлива.

23. а) Найдите в тексте А предложения, в которых сказуемые выражены глаголами в страдательном залоге. Переведите эти предложения.

б) Найдите в тексте А предложения, в которых сказуемые выражены модальными глаголами с инфинитивом в страдательном залоге. Переведите эти предложения.

24. Представьте себе, что вы лектор. Расскажите об осадочных породах, используя следующую схему:

98_____________________________________________Unit

4

25. Подготовьте сообщение аа тему "Sedimentary Rocks", используя следующий план:

1.The characteristic feature of sedim entary rocks.

2.Sediments (mechanical, chemical, organic) and their formation.

3.The practical value of sedim entary rocks.

ГРАММАТИКА

1. О собенности употребления и способы перевода страдательного залога

ПРЕДТЕКСТОВЫЕ УПРАЖНЕНИЯ

26. а) П рочитайте вслух следующие слова:

[ее] — ex'pand, con'tract, crack, 'gravel, 'fracture

[л] — des'tructive, des'traction, 'substance, 'colour, re'suit [i:] — 'equal, 'reason, heat, peak, ma'rine

[e]— 'desert, ac'celerate, sue'cession, 'weathering, subjected

[э]— 'soluble, 'moderate, phe'nomenon

[ju:] — 'uniform, 'uniformly, pure, 'purely

б) Прочитайте следующие слова и запомните их пвошзиовкние:

disintegration [dis,mti'greif(3)n], climate ['klaimit], fissure I'fifa], equal ['i:kwal], unequal [An'i:kwal], marine [ma'ri:n], mountain ['mauntm], mountainous ['mauntmas), phenomenon [ffnomman]

27. П рочитайте следую щ ие слова и сочетания слов 1-2 раза про себя, затем вслух и постарайтесь запомнить их .

hardness, thickness, softness, effectiveness, darkness

б) Заполните пропуски в предложениях существительными, образовавот выделенных прилагательных:

1. Soft rocks (mudstone, clay) are easily penetrated with a tool and do not greatly resist the separation of a part from the mass. The main property of such rocks is ... .

2.Hard rocks may be strong (sandstone, granite, magnetite) and very strong (quartzite, diabase, etc.). These rocks have the highest resistance to penetration with a tool. Their main property is ....

3.The coal seam is thick and its ... is more than three metres. 4.The modern equipment is effective.Its ...is greater than that

of the old one.

Unit 4

_____________________________________________________

103

these cracks or fissures are hardly noticeable but gradually they become wider and deeper until the whole surface of rock is finally transformed into gravel, sand or dust.

In the regions of a moderate or cold climate, where the temperature in winter goes down to below 0 (zero), the decomposition of rocks is greatly facilitated by the action of water. When water freezes it increases in volume and develops enormous lateral pressure. Under the action of water, rocks decompose to pieces of varied forms and sizes.

The decomposition of rocks under the direct influence of heat and cold is called physical weathering.

Rocks are subjected not only to physical decomposition but also to chemical weathering, i.e. to the action of chemical agents, such as water, carbon dioxide and oxygen. In a general way, chemical weathering is an acid attack on the rocks of the Earth's crust, in particular an attack on the most abundant minerals — quartz (sand) and aluminosilicates (clays). Only few minerals and rocks are resistant to the action of natural waters. The solvent action of water is stronger when it contains carbon dioxide. Water causes more complex and varied changes. With the participation of oxygen and carbon dioxide up to 90 per cent of rocks is transformed into soluble minerals, which are carried away by the waters.

Organisms and plants also take part in the disintegration of rocks. Certain marine organisms accelerate the destruction of rocks by making holes in them to live in. The action of plants can often be even more destructive. Their roots penetrate into the fissures of rocks and develop the lateral pressure which fractures and destroys rocks.

32. Укажите, жжкме предложены соответствуют содержанию текста. Подтвердите свои ответы фактами из текста.

1.The process of sedimentation is called weathering.

2.The change in temperature causes physical weathering.

3.As a rule during the night rocks expand.

4.When freezing water decreases in volume and develops enor mous lateral pressure.

5.The decomposition of rocks is due to the influence of heat and

cold.

6.As a rule water contains_dissolved mineral substances.

7.The solvent action of water is stronger when it does not con tain carbon dioxide.

8.It should be noticed that the action of organisms and plants is destructive.

9.Certain marine organisms accelerate the destruction of rocks.

33.Ответьте на следующие вопросы:

1.What process ia called weathering?

2.What process is called physical weathering?

3.Where can the phenomenon of physical weathering be best observed?

4.What process is called chemical weathering?

5.What substances can act as solvents?

6.Are all minerals and rocks resistant to the action of natural waters or only few minerals and rocks can resist the action of water?

7.How do organisms act on the destruction of rocks?

34.а) Найдите в правой колонке русские эквиваленты следующих слов

исочетаний слов:

9. to penetrate into fissures

б) Найдите в правой колонке английские эквиваленты следующих слов и сочетаний слов:

9.куски породы различных размеров

35. а) Внимательно прочитайте материал в рамке и назовите признаки

приведенных ниже существительных:

Определители существительных

Артикли — a, an, the.

Указательные местоимения — this — these, that — those. Притяжательные местоимения — my, his, her, its, our и т.д. Притяжательный падеж имени существительного —

Britain's deposits.

Неопределенные местоимения — some, any, each, every. Количественные местоимения — many, much, (a) little,

(a) few, a lot of и т.д. Количественные и порядковые числительные — two

countries, the third place. Предлоги — after, at, before, in, on, with и т.д.

our country, the country, any country, each country, many countries, these countries, a small country, whose country, two big countries;

the discovery, after the discovery, each discovery, such discoveries, what discovery, few discoveries, a new discovery

б) Назовите признаки, позволяющие определить, какой частью речи являются приведенные слова:

their study — they study; the use — we use; the increase — they increase; coal output decrease — coal output decreases; the last lectures — the lectures last; this place — it places; the raw material bases — the country bases its economy on ...

36. Заполните пропуски в предложениях, выбрав из предлагаемых в скобках вариантов соответствующее слово:

1.There are ... causes of weathering, but ... depends on the change in temperature, (many, much)

2.As is known, only ... minerals and rocks are resistant to the action of natural waters, (little, few)

3.The roots of plants developed ... pressure which did not frac ture overlaying rocks, (little, few)

4.A new geological map of the region will appear in a ... years.

(little, few)

5. ... minerals undergo changes. They have already undergone ...

transformation, (пищу, much)

6. Now there are ... sources of energy as important as atomic energy, (little, few)