As for as I know; as is known; as for; I'd like to say a few words about.; it should be noted that.; as a rule; generally speaking и др

Rocks of the Earth's Crust

I I

sedimentary rocks igneous rocks metamorphic rocks

I I I

mechanical, chemical intrusive rocks, rocks structure

and organic extrusive (volcano) |

sediments rocks water in metamorphism

I I I

Practical value of each type of rocks (metals they are rich in)

42. Прочитайте текст В без словаря и скажите, о чем ои. Слова для понимания текста:

profit — прибыль; польза

residual — осадочный

alloy — сплав

cast iron — чугун

ТЕКСТ В

Minerals that make up rocks, are defined as inorganic sub­stances which occur naturally and have a definite chemical composi­tion and physical properties which vary within known limits.

The major properties are colour, crystal form, hardness, cleavage and others. Cleavage is one of the most diagnostically useful mineralogi-cal properties which can be found throughout the mineral.

Minerals of use to man can be grouped into two broad catego­ries: 1) metals, such as aluminium, copper, gold, silver, iron, tin, platinum, chromium, nickel, lead and zinc, and 2) non-me­tallic minerals, such as diamonds, salt, limestone, cement, sul­phur, and asbestos. When minerals occur so that they can be worked at a profit they are called ore deposits. Mineral deposits are seldom equally rich throughout.

Unit 5_____________________________________________ 135

Economic minerals are those which are of economic impor­tance and include both metallic and non-metallic minerals.

Most minerals consist of several elements. Such elements are oxygen, silicon, titanium, aluminium, iron, magnesium, calcium, sodium, potassium and hydrogen. They make up more than 99 per cent by weight of all the rock-forming minerals. Of these, alu­minium, iron and magnesium are industrial metals. The other metals are present in small quantities, mostly in igneous rocks.

For example, iron is one of the most abundant metals in the Earth's crust. There are three important classes of iron deposits: deposits associated with igneous rocks; residual deposits and sedi­mentary deposits. Iron deposits associated with igneous rocks are usually small but very rich bodies either of haematite or magnetite. Large concentrations have been successfully mined in Pennsylvania (the USA) and in the Russian Federation.

Residual deposits of iron minerals are formed wherever weather­ing occurs. Iron deposits formed this way are very widespread. It should be stressed that the residual deposits were among the first to be exploited by man.

Sedimentary iron deposits make up most of the world's current production.

As the essential component of every variety of steel, iron is ob­viously the most important of all industrial metals. It has played a large part in the development of our modern civilization. Iron ores are mainly used for producing cast iron, steels and ferro-alloys. From a scientific point of view, iron's most important property is that it becomes magnetized.

The magnetic iron ore is the main wealth of the Kursk Magnetic Anomaly (KMA). It is necessary to say that only in the last century was the secret of the unusual magnetism of enormous iron ore masses discovered underground.

Iron fields are worked by surface mining which is more eco­nomical. But the KMA is rich not only in iron ores. Its deposits contain bauxite, phosphorite, cement, sand and clays.

43. Разделите текст В м логические части. В каждой иста текста
вайднте предложение, передающее ее основную мысль. Озаглавьте каждую
часть текста В.

44. Найдите в тексте В ответы на следующие вопросы:

1. Why is cleavage the most important property of minerals?

2. How can ore deposits be defined?

136_______________________,______________________ Unit 5

3. What are iron ores used for?

4. What is the KMA rich in?

45. Найдите в тексте информацию по следующим вопросам:

1. The main groups of minerals.

2. The composition of minerals.

3. The important classes of iron ore deposits.

4. Industrial importance of iron ores.

5. The characteristic feature of the KMA.

46. Определите, какой из трех заголовков наиболее соответствует
содержанию текста В:

1. Mineral Deposits.

2. The Composition of Minerals.

3. Iron Ores of Importance to Man.

47. Расскажите, какая информация из текста В была для вас новой.
Отметьте, какие факты вам были уже известны.

48. Переведите текст со словарем:

New Discoveries about the "Blue Planet"

Specialists from many ground services have assessed the practi­cal use of observations from outer space. The most effective use of the data obtained was made in the field of geology.

A look from outer space identified fundamentally new geological objects which had not been previously studied or mapped. The satellites helped establish the location of abyssal fractures stretching over hundreds and thousands of kilometres and cutting across the whole systems of folds, platforms and the ocean bed. They penetrate deep into the Earth and often act as supply canals of fusions and mineral-enriched solutions. About 20 such abyssal fractures have been identified on the territory of Russia. Successful development of space research makes it possible to survey the Earth's resources from space by satellites. Besides, the surveys by satellites give us information on other parts of the solar system. This has given rise to a new science of "geology of planets" called astrogeology. All this has greatly expanded the viewpoint of the geologist. At the present time geology, astronomy, meteorology, oceanography and geophysics are coming closer together and scientists believe that such combination of sciences must be used together to study the whole Earth.

UHIT 6 Sources of Energy

A. Грамматика.

Герундий (The Gerund).
Текст A. Fossil Fuels.

Б. Грамматика.

Причастие настоящего времени (The Present Participle).
Текст Б. Coal and Its Classification.

B. Текст В.

Дискуссия. Энергия и жизнь.

А

ГРАММАТИКА