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disrupt the natural vegetation, have greatly accelerated the rate of soil erosion. Without
the stabilizing effect of plants, the soil is more easily swept away by the wind or carried
downslope by sheet wash.
Natural rates of soil erosion vary greatly from one place to another and depend
on soil characteristics as well as such factors as climate, topography, and type of
vegetation.
It is more difficult to measure the loss of soil due to wind erosion. However, the
removal of soil by wind is generally much less significant than erosion by flowing water
except during periods of prolonged drought. When dry conditions prevail, strong winds
can remove large quantities of soil from unprotected fields.

Task 3. List all the important terms from the text and define them.

Task 4. Answer the questions:
1. Why are soils a vital resource?
2. How have human activities affected the rate of soil erosion?

Test yourself
Task 1. Tell whether the sentences are true or false. Correct the false ones.
1. Soil is referred to as a system.
2. Soil forms where the geosphere, the atmosphere, the hydrosphere, and the
biosphere meet.
3. When environmental changes occur, in climate, vegetative cover, or animal
(including human) activity, the soil does not change.
4. Earth’s land surface is covered by soil, the layer of rock and mineral fragments
produced by weathering.
5. Soil is a combination of mineral and organic matter, water, and air.
6. Soil water contains many soluble nutrients.
7. Air in the pore spaces of soil is the source of necessary oxygen and carbon dioxide
for most microorganisms and plants that live in the soil.
8. Parent material is a major factor influencing a newly forming soil.
9. Variations in temperature and precipitation determine whether chemical or
mechanical weathering predominates.
10. Soils are the foundation of the human life-support system.

Task 2. Fill in the gaps with the suitable words and word combinations.
Sediment, type of vegetation, rock cycle, rate of soil, soil erosion
Soil erosion is a natural process. It is part of the constant recycling of Earth
materials that we call the … . Once in a stream channel, soil particles, which can now be
called …, are transported downstream and eventually deposited. Rates of … vary from
one place to another and depend on the soil’s characteristics as well as on such factors
as climate, slope, and …. Human activities have greatly accelerated the … erosion in
many areas.

UNIT 11
MINERALOGY
Part 1

Task 1. Read and memorize the following words:
alloy - сплав gravel - гравій, крупний пісок;
галечник

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