- •8.1.1. Practise saying the following words. Translate them into Ukrainian:
- •8.1.3. Read the text and compare your ideas with the actual points discussed in the text.
- •8.1.4. Read the text again and answer the following questions:
- •Vocabulary
- •8.1.5. Fill in the blanks with the words from the Vocabulary:
- •8.1.6. Fill in prepositions where necessary:
- •8.1.7. A. Match the words to make partnerships. Use the expressions in sentences of your own:
- •8.1.8. A. Match the words from the text to their meanings below:
- •8.1.9. Translate the following fragments from the text into Ukrainian:
- •8.1.10. Match the pairs of words similar in meaning:
- •8.1.11. A. Complete the table where possible:
- •8.1.12. Translate into English:
- •8.2.2. Read the text. Fill in the gaps with the following phrases. There is one extra phrase which you don’t need to use:
- •8.2.3. Read the text again. Decide which statements refer to Texas (t) and which to Louisiana (l):
- •8.2.5. Read the text and convey its gist in English.
- •8.2.6. Read the following text and think of the word which best fits each gap. Use only one word in each gap. There is an example at the beginning (00).
- •8.2.7. Read the following text and think of the word which best fits each gap. Use only one word in each gap. There is an example at the beginning (00).
- •8.2.8. For questions 1-15, read the text below and decide which answer (a, b, c or d) best fits each gap. There is an example at the beginning (0).
UNIT 8
Section 1. EROSION AND WEATHERING
Figure 8.1 Headland Erosion
8.1.1. Practise saying the following words. Translate them into Ukrainian:
Mechanical /mɪˈkænɪk(ə)l/, chemical /ˈkemɪk(ə)l/, boulder /ˈbəʊldə(r)/ versatile /ˈvɜː(r)sətaɪl/, sledgehammer /ˈsledʒˌhæmə(r)/, lichen /ˈlaɪken/ or /ˈlɪtʃ(ə)n/, plow (Am. E.)/ plough (Br. E) /plaʊ/, acidic /əˈsɪdɪk/, terrain /təˈreɪn/, obscure /əbˈskjʊə(r)/.
8.1.2. You are going to read a text about natural geological processes. Look at its heading and the words in bold type and try to guess which points from the list below are likely to be discussed in the text:
the connection between weathering and erosion;
landscapes resulting from the two processes;
the structure of rock;
the role of water and temperature in weathering;
biological factors contributing to weathering;
chemicals that can affect rock;
the effect of global warming on rock;
sediments deposited by glaciers;
the adverse effects of industrial and agricultural development on land.
8.1.3. Read the text and compare your ideas with the actual points discussed in the text.
Erosion and Weathering
National Geographic // http:// natgeotv.com/uk
Press, F., Siever, R. Understanding Earth/ 2nd Ed. N. Y.: W. H. Freeman and Company, 1998.
After tectonics and volcanism have made mountains, chemical decay and physical breakup join with rainfall, wind, ice, snow, and downward movements of material over Earth’s surface to wear away those mountains.
Weathering and erosion not only are closely interwined, they are major geological processes in the rock cycle. With tectonics and volcanism, other elements of the rock cycle, weathering and erosion change the form of Earth’s surface and alter rock materials, converting igneous and other rocks into sediment and forming soil. The processes are definitively independent, but not exclusive. Weathering is the mechanical and chemical “hammer” that breaks down and sculpts the rocks. Erosion transports the fragments away.
In some instances, weathering and erosion are inseparable. When a rock such as pure limestone or rock salt weathers by dissolving in rainwater, for example, all of the material is completely dissolved and carried away in the water as ions in solution. Material dissolved during chemical weathering contributes most of the dissolved material in the oceans.
Working together they create and reveal marvels of nature from tumbling boulders high in the mountains to sandstone arches in the parched desert to polished cliffs braced against violent seas.
Water is nature's most versatile tool. For example, take rain on a frigid day. The water pools in cracks and crevices. Then, at night, the temperature drops and the water expands as it turns to ice, splitting the rock like a sledgehammer to a wedge. The next day, under the beating sun, the ice melts and trickles the cracked fragments away.
Repeated swings in temperature can also weaken and eventually fragment rock, which expands when hot and shrinks when cold. Such pulsing slowly turns stones in the arid desert to sand. Likewise, constant cycles from wet to dry will crumble clay.
Bits of sand are picked up and carried off by the wind, which can then blast the sides of nearby rocks, buffing and polishing them smooth. On the seashore, the action of waves chips away at cliffs and rakes the fragments back and forth into fine sand.
Plants and animals also take a heavy toll on Earth's hardened minerals. Lichens and mosses can squeeze into cracks and crevices, where they take root. As they grow, so do the cracks, eventually splitting into bits and pieces. Critters big and small trample, crush, and plow rocks as they scurry across the surface and burrow underground. Plants and animals also produce acids that mix with rainwater, a combination that eats away at rocks.
Rainwater also mixes with chemicals as it falls from the sky, forming an acidic concoction that dissolves rock. For example, acid rain dissolves limestone to form karst, a type of terrain filled with fissures, underground streams, and caves like the cenotes (specific features of karst relief) of Mexico's Yucatán Peninsula.
Back up on the mountains, snow and ice build up into glaciers that weigh on the rocks beneath and slowly push them downhill under the force of gravity. Together with advancing ice, the rocks carve out a path as the glacier slumps down the mountain. When the glacier begins to melt, it deposits its cargo of soil and rock, transporting the rocky debris toward the sea. Every year, rivers deposit millions of tons of sediment into the oceans.
Without the erosive forces of water, wind, and ice, rock debris would simply pile up where it forms and obscure from view nature's weathered sculptures. Although erosion is a natural process, abusive land-use practices such as deforestation and overgrazing can expedite erosion and strip the land of soils needed for food to grow.
Did You Know?
All rocks weather and erode, but the manner and rate of their weathering vary. The four key factors that control the fragmentation and decay of rocks are the properties of the parent rock, the climate, the presence or absence of soil, and the length of time they are exposed to atmospheric conditions. Granite is among the hardiest. Sandstone, by contrast, is just sand particles bonded by water and is more prone to physical erosion.