Sedimentary Rocks

Sediments laid down by water, wind, or ice are consolidated into rock by the weight of overlying deposits and by the gradual cementing of their grains with material deposited from underground water. The resulting rocks are usually characterized by the presence of distinct, somewhat rounded grains that have not grown together like the crystals of igneous rocks. A few sedimentary rocks, however, consist of intergrown mineral grains formed by precipitation from solution in water. Since sediments are normally deposited in layers, the majority of sedimentary rocks have a banded appearance owing to slight differences in colour or grain size from one layer to the next. Sedimentary rocks may often be recognized at a glance by the presence of fossil – remains of plants or animals interred with the sediments as they were laid down.

Grammar focus the system of tenses

Task 1. Study the following table and get ready to practice the use of the Present Simple and Present Continuous.

Formation		Present Simple	Present Continuous
	Statement	Констатация факта V, Vs (3л.ед.ч.) Mr. A speaks good English	П роцесс am is + Ving are Mr. A is speaking English now.
	Question	D o Does + S + V Does Mr. A speak English?	a m is + S + Ving are Is Mr. A speaking English now?
	Negative	... do not (don’t) +V ... does not (doesn’t) + V Mr. A doesn’t speak French.	... am not (‘m not) + Ving ... is not (isn’t) + Ving ... are not (aren’t) + Ving Mr. A isn’t speaking French now.
Use
Typical words land phrases

Do Does

+ S + V

Task 2. Circle the correct word or phrase.

1. I read/ am reading a newspaper at least once a weak.

2. Does Gary ever talk/ is Gary ever talking about his expedition to the Amazon jungle?

3. Each water molecule contains/ is containing two hydrogen atoms and one oxygen atom.

4. The each is forming/ forms an extremely small portion of the universe.

5. When one passes/ is passing from place to place on the surface of the earth the appearance of heaven changes/ is changing constantly.

6. Geology studies agencies and processes which continually alter/ are altering the earth’s surface.

7. Now science exercises/ is exercising a decisive influence on technology, creating new problems for it.

8. Holiday travel becomes/ is becoming more and more popular with every day.

9. Word land of great Britain are occupying/ occupy 7 percent of the surface.

10. The earth constantly rotates/ is rotating on its axis from west to east.

Task 3. Complete using the correct Present Simple or Present Continuous form of the verbs in brackets.

1. Alan _____ (study) to be a geographer but I don’t think he (enjoy) it.

2. Energy _____ (occur) in several forms.

3. The amount of energy used in agriculture _____ (increase) from year to year.

4. Nowadays human activity even in the far North of Russia, North America and Greenland _____ (damage) nature.

5. The planet _____ (get) warmer causing the ice in Antarctica to melt.

6. The Rocky Mountains still _____ (rise) as the pressure between the two plates _____ (continue).

7. Rivers _____ (get) their water from rainfall and melting snow.

Task 4. Study the following table and get ready to practice the use of the Present Perfect and the Present Perfect Continuous.

Task 5. Complete using the correct Present Perfect or Present Perfect Continuous form of the verbs in brackets.

1. Mapping _____ (make) great advances in the last years.

2. Men _____ (use) maps for thousands of years.

3. The passion for literature _____ (become) a national feature of the Icelanders.

4. Life _____ (originate) in the areas growing from small molecules if amino acids and nucleotides.

5. Meteorologists _____ (look for) reliable ways of forcasting the weather.

6. Men _____ (give) different names to different parts of the sea.

7. Oil and natural gas _____ (to transform) countries such as Saudi Arabia, Libya and the UAE.

8. The last 100 years _____ (be) a time when huge cities _____ (grow).

9. Many plant and animal species _____ (lose) their habitat and _____ (become) extinct because of deforestation.

Task 7. Complete using the correct form of the verbs in brackets.

1. In 120 scientists _____ (invent) instruments that _____ (measure) the depth of water.

2. The famous navigator J. Cook _____ (study) astronomy with great enthusiasm.

3. Some of the world’s oldest civilizations _____ (begin) in the river valleys of North Africa and the Middle East.

4. Before modern industry _____ (begin) in Northern Europe, a good climate and plentiful natural resources _____ (encourage) human settlement and development.

5. The Rocky Mountains _____ (form) where the Pacific Plate _____ (press) against the North American plate.

6. By 1900 the people _____ (cut down) 80 percent of the forests on Prince Edward Island and diseases _____ (destroy) much of what _____ (remain).

7. Galileo _____ (discover) the four satellites of Jupiter over three centuries ago.

8. When the earth _____ (reach) the size of the planet Mars it _____ (have) primitive continental platforms and ocean basins.

9. Beginning from its early formative stage the earth _____ (change) constantly.

10. The scientists _____ (learn) that the oldest rocks in our country _____ (form) 1600-1800 million years B.C.

11. During the last 2.6 million years the climate on the Earth _____ (change constantly).

12. 20000 people _____ (die) in six serious earthquakes in Turkey in 1999. Scientists _____ (warn) that the country’s industrial region and homes had been bailf in the area of highest seismic risk.

Task 9. Circe the correct word or phrase.

1. I’m becoming/ going to become an explorer when I grow up.

2. One day, people are living/ will live on Mars in special buildings.

3. This year, more than a million tourists shall/ will visit our local area.

4. If we do not/ will not take action to protect the earth’s atmosphere, it is going to/ will soon become unable to protect us.

5. According to the “closed universe” theory the universe contracts/ will contract eventually.

6. No matter how high a mountain, erosion is wearing away/ will wear away eventually it.

7. Wherever there are minerals worth extracting mining will occur/ is occurring.

8. By 2030 more than 60% of people are going to/ will live in cities.

9. The increase of greenhouse gases in the forthcoming 30 or 10 years is affecting/ will affect the inhabitants of the planet.

Task 10. Complete using will or be going to.

If the destruction of the forest continues at the same rate there (1) _____ (be) nothing left in the nearest future. What (2) _____ (happen) if more of the Amazon forest is cut down? According to climatologists, two things are likely to happen^ there (3) _____ (be) serious effects of the world’s climate, and the air that we breathe (4) _____ (lose) some of its oxygen.

If we lose the tropical forest, the are (5) _____ (contain) much less oxygen and much more carbon dioxide, It (6) _____ (become) difficult to breathe. With more carbon dioxide in the air, the temperature (7) _____ (rise), the icecaps at the North and South Poles (8) _____ (melt), the sea level (9) _____ (rise) and hundreds of coastal cities (10) _____ (be flooded). All scientists agree that if we destroy the Amazon forest it (11) _____ (be) environmental suicide – life on earth (12) _____ (become) difficult, even impossible.

Task 11. Read the following text putting the verbs in brackets into the correct form. Get ready to discuss its main points. Make an outline of the text and render its contents.