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very different and comparatively hostile surface environment. In response, this rock
mass will gradually change. This transformation of rock is what we call weathering.

Task 3. Answer the following questions, using the vocabulary from Task 1.
1. What is an external process?
2. How old were mountains, lakes, and deserts, as people believed it, 200 years ago?
3. What is the real age of Earth?
4. Define: weathering; mass wasting; erosion.
5. Why is weathering so important for our nature? To humans?
6. What are the most important types of weathering?
7. What is the difference between mechanical weathering and chemical weathering?
8. Why does rock weather?

Task 4. Try to guess what:
1. involves a chemical transformation of rock into one or more new compounds?
2. is accomplished by physical forces that break rock into smaller and smaller pieces
without changing the rock’s mineral composition?
3. is the transfer of rock and soil downslope under the influence of gravity?
4. is the physical breakdown (disintegration) and chemical alteration (decomposition)
of rocks at or near Earth’s surface?
5. is the physical removal of material by mobile agents such as water, wind, or ice?

Task 5. Find English equivalents for the following (see the text). Try to
build up your own sentences with them.
Траплятись на поверхні Землі; бути відповідальним; довгострокові або
постійні утворення на Землі; динамічне тіло; вулканічна діяльність; відбуватись
навколо нас; не змінюючи мінеральну структуру гірської породи; хімічне
перетворення або зміна; оточуюче середовище; основна частина циклу утворення
гірської породи.

Task 6. Look at Figure 9.1. What type of weathering does it show? What
does this type of weathering prove?

Task 7. Give a short summary of the text from Task 2.

Grammar focus

Perfect Tenses
Task 1. Read the sentences. Name the grammar tenses of the verbs.
Translate the sentences paying special attention to the Perfect Tense form of the
verbs.
1. Unlike the young mountain belts, which have formed within the last 100 million
years, the interiors of the continents have been relatively stable (undisturbed) for
the last 600 million years or even longer.
2. During the past 60 years, oceanographers using modern depth-sounding
equipment have gradually mapped significant portions of the ocean floor.
3. From these studies they have defined three major regions: continental margins,
deep-ocean basins, and oceanic (mid-ocean) ridges.
4. Volcanic activity has also produced several large lava plateaus.
5. The oceanic ridge system consists of layer upon layer of igneous rock that has
been fractured and uplifted.

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