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Part 1 Unit 1 Rocks and their properties

The Earth’s crust

1. Before reading the text, study the vocabulary.

the Earth’s crust	Земная кора
origin	Происхождение
sedimentary rocks	Осадочные породы
decay	Разложение, распад
plant relics	Растительные остатки
igneous rocks	Изверженные породы
to solidify	Затвердевать
surface	Поверхность
metamorphic rocks	Метаморфическая порода
fossil fuels	Органическое топливо
to dig up	Копать, выкапывать
sulphur	Сера
oxygen	Кислород
nitrogen	Азот
flux	Постоянное движение, изменение
folding	Складчатость, складчатое залегание
fault	Сдвиг породы, разлом, трещина

2. Write down the transcription of the following words and practise their pronunciation:

• circumstance

• hydrocarbons

• hydrogen

• carbon

• sulphur

• nitrogen

3. Read and translate the text.

The Earth’s crust consists of a variety of rocks, formed under different circumstances. Rocks consist of one or more composite minerals. A mineral is a substance formed by nature, it may be an element or may consist of chemical compounds containing several elements. Rocks are classified into three main groups on the basis of their origin and the way in which they were formed:

• sedimentary rocks which were formed by the mechanical or chemical action of water, wind and frost or by the decay of the remains of organisms and the accumulation of plant relics;

• igneous rocks which were formed when a magma solidified deep down in the earth’s crust (plutonic rock), or as it rose towards the surface (dyke rock) or on the surface (volcanic rock);

• metamorphic rocks which were formed either by the transformation of igneous or sedimentary rocks, in most cases by an increase in pressure and heat.

Fossil fuels such as coal, gas and crude oil represent energy that has been concentrated by the decay of organic materials (plants and animals) accumulated in the geologic past. The word fossil (derived from the Latin fodere "to dig up") originally referred to anything that was dug from the ground, par­ticularly a mineral. Crude oil is a mixture of hundreds of different hydrocarbons (compounds composed of hydrogen and carbon) together with the small amount of other elements such as sulphur, oxygen and nitrogen. Hydrocarbons are usually found in porous sedimentary rocks, which are layered or stratified, although sometimes they may be found in igneous and metamorphic rocks as well, where the geological formation allowed the oil to collect from a wide area. They are most abundant in sandstone, dolomite, shale and limestone.

The earth’s crust is in a constant state of flux and the various rock formations may be subjected to very powerful forces. The result is deformation in one way or another, and in nature we can observe pronounced folding, crushed zones, faults and other phenomena that can have a telling effect on drilling.

4. Give the adequate Russian variants for the following word combinations:

Composite minerals; chemical compounds; on the basis of their origin; the accumulation of plant relics; to solidify from magma; the transformation of igneous or sedimentary rocks; the decay of organic materials; crude oil; the geological formation; to be abundant; a constant state of flux; to be subjected to powerful forces; pronounced folding; a telling effect on drilling.

5. Find the English equivalents for the following words and word combinations:

Земная кора; состоять из различных пород; сформироваться под разными обстоятельствами; содержать несколько химических элементов; осадочные породы; изверженные породы; метаморфические породы; органическое топливо; сырая нефть; углеводороды; напластовываться; подвергаться чему-либо; резко выраженное складчатое залегание; значительный эффект.

6. Find the synonyms:

• to be composed of

• consolidated

• bedded, layered

• raw oil, base oil

• plentiful

7. Match the minerals and the rocks they are found in and translate the names of the minerals into Russian:

Metamorphic rocks	Granite, diorite, quartz, mica, basalt, rhyolite
Sedimentary rocks	Gneiss, quartzite, mica-schist, slate, marble
Igneous rocks	Sandstone, conglomerate, siltstone, limestone, dolomite, shale

Practice the pronunciation of the minerals!

8. Agree or disagree with the following statements:

1. The rocks of the Earth's crust are divided into two main groups.

2. Rocks consist of chemical compounds containing several elements.

3. Igneous rocks have crystallized from solidified magma.

4. Sedimentary rocks are stratified, thus stratification is the most important characteristic of sediments and sedimentary rocks.

5. Metamorphic rocks were formed by the transformation of igneous or sedimentary rocks by decrease in pressure and heat.

6. Fossil fuels such as coal, gas and crude oil represent energy that has been concentrated by the decay of organic materials.

7. Crude oil can be found in porous sedimentary rocks.

8. Crude oil is a mixture of hundreds of different hydrocarbons.

9. The earth’s crust is in a constant state of flux and the various rock formations may be subjected to very powerful forces.