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hot spot marking the current position of the remaining tail of the plume (FIGURE 8.2,
C).

Task 2. Answer the questions (in written form):
1. What is the source of magma for intraplate volcanism?
2. At which type of plate boundary is the greatest quantity of magma generated?

Task 3. Look at Figure 8.2, C and D. What is the difference between
intraplate oceanic volcanism and intraplate continental volcanism? Answer the
question in written form.

Task 4. Look at Figure 8.4. This is a simplified drawing showing a wide
variety of natural hazards associated with volcanoes. Make a short report about
the hazards.

Test yourself

Task 1. Tell whether the sentences are true or false. Correct the false ones.
1. Calderas are large depressions with diameters that exceed 1 km and have a
somewhat triangular form.
2. Most calderas are formed by the collapse of the summit of a large composite
volcano following an explosive eruption of silica-rich pumice and ash fragments.
3. The greatest volume of volcanic material is extruded from fractures in the crust
called fissures.
4. A dome-shaped mass is called a lava dome.
5. One rare type of pipe is called a diatreme.
6. Cinder cones are not easily eroded.
7. Basaltic shields that emit very fluid lavas comprise most of the islands of the deep
ocean basins.
8. Volcanic structures that appear to be somewhat randomly distributed in the
interiors of the continents are usually found in Australia.
9. Decompression melting is the most common process by which mantle rocks melt.
10. Geologists have determined that the mantle beneath hot spots must be 100 to
150 °C hotter than normal mantle material.

Task 2. Choose the best variant:
Most passive / active volcanoes are associated with plate / continental
boundaries. Active areas of volcanism are found along mid-ocean ridges where seafloor
spreading is occurring (convergent / divergent plate boundaries), in the vicinity of ocean
trenches where one plate is being subducted beneath another (convergent/ divergent
plate boundaries), and in the interiors of plates themselves (convergent plate volcanism /
intraplate volcanism / divergent plate volcanism). Rising plumes of hot mantle rock are
the source of most intraplate volcanism.

UNIT 9
EARTH’S EXTERNAL PROCESSES
PART 1
WEATHERING AND SOIL

Task 1. Read and memorize the following words:
alteration – зміна, перебудова, disintegration – розпад, руйнування

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