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Task 5. Do the following: relate the classification of igneous rocks to
Bowen’s reaction series, provide the examples.

Task 6. Define the following terms:
 magma assimilation;
 magma mixing;
 partial melting;

 magma composition.

Task 7. Read the short note. Did you know about it?
Quartz watches actually contain quartz crystals that allow them to keep time.
Before quartz watches, timepieces used some sort of oscillating mass or tuning fork.
Cogs and wheels converted this mechanical movement to the movement of the hands. It
turns out that if voltage is applied to a quartz crystal, it will oscillate with a consistency
that is hundreds of times better for timing than a tuning fork. Because of this property,
and modern integrated-circuit technology, quartz watches are now built so cheaply that
they are sometimes given away in cereal boxes. Modern watches that employ
mechanical movements are very expensive indeed.

Test yourself

Task: Tell whether the sentences are true or false. Correct the false ones.
1. Earth’s crust and mantle are composed primarily of molten rock.
2. The decrease in temperature with depth is known as the geothermal gradient.
3. Pressure increases with depth.
4. Water content is another important factor affecting the melting temperature of
rock.
5. During the crystallization process, the composition of the remaining liquid portion
of the magma does not change.
6. According to Bowen’s reaction series, if the solid components of a magma remain
in contact with the remaining melt, they will chemically react and change
mineralogy.
7. The formation of one or more secondary magmas from a single parent magma is
called magmatic differentiation.
8. The process of magma’s migration through the crust when it may incorporate
some of the surrounding host rock is called assimilation.
9. The composition of magma can be altered through magma mixing.
10. The unmelted crystals are those of minerals with lower melting temperatures.

UNIT 5
MAGMA
Part 2

Task 1. Read and memorize the following words:
invariably - незмінно, постійно concordant - який узгоджується,
відповідає; гармонічний
emplacement – місце розташування dike – дайка
preexisting – існуючий; той, що існував sill - силь; пластова інтрузія
раніше
bedding surface –поверхня, яка solitary - окремий
утворена осадовими породами
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