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Chapter 9 Plate Tectonics Chapter Test
Multiple Choice
Write the letter that best answers the question or completes the statement on
the line provided.
1. Wegener’s continental drift hypothesis stated that all the
continents once joined together to form
a. two major supercontinents.
b. two major supercontinents and three smaller continents.
c. one major supercontinent.
d. three major supercontinents.
2. The hypothesis of continental drift is used to explain an
event that happened
a. two million years ago.
b. two hundred million years ago.
c. two billion years ago.
d. two hundred billion years ago.
3. What evidence supports Wegener’s hypothesis?
a. The same mammal species exist on different continents.
b. Major rivers on different continents match.
c. Land bridges still exist that connect major continents.
d. Fossils of the same organism have been found on
different continents.
4. Evidence about ancient climates indicates that
a. glacial ice once covered much of what is now India and
Australia.
b. the countries found in the Northern Hemisphere today
were once centered over the South Pole.
c. no continents occupied the Northern Hemisphere.
d. the countries found in the Southern Hemisphere today
were once centered over the North Pole.
5. Which of the following results when divergence occurs
within the oceanic lithosphere?
a. seafloor spreading
b. a rift valley
c. a volcano chain
d. a mountain range
6. What forms when one oceanic plate is forced beneath
another plate?
a. an ocean basin
b. ocean ridges
c. a subduction zone
d. a rift valley
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7. Which of the following does NOT occur at a subduction
zone?
a. The leading edges of both plates are bent downward.
b. Oceanic crust is pushed down into the mantle.
c. One oceanic plate moves into another oceanic plate.
d. One continental plate moves into an oceanic plate.
8. Which of the following is NOT evidence of sea-floor
spreading?
a. the alternation of polarity in segments of the ocean floor
b. the relationship between earthquakes and plate
boundaries
c. analysis of seafloor sediments
d. the distribution of ice sheets across the planet
9. Which of the following is true of a rock that has the property
of paleomagnetism?
a. Rocks formed millions of years ago show the location of
the magnetic poles at the time of their formation.
b. All rocks, regardless of when they are formed, will
eventually possess the same polarity.
c. A major shift in polarity occurred in all rocks that were
formed one million years ago.
d. A rock possesses a specific polarity depending on where it
is formed.
10. According to the theory of plate tectonics, the
a. asthenosphere is divided into plates.
b. lithosphere is divided into plates.
c. asthenosphere moves over the lithosphere.
d. asthenosphere is strong and rigid.
11. What is the average movement of lithospheric plates?
a. 5 in. per year
b. 50 in. per year
c. 5 cm per year
d. 50 cm per year
12. What kind of plate boundary occurs where two plates grind
past each other without destroying the lithosphere?
a. divergent boundary
b. convergent boundary
c. transform fault boundary
d. transitional boundary
13. Which of the following is a geographic example of a
tranform fault boundry?
a. the East African Rift valley
b. the Mid-Atlantic Ridge
c. the San Andreas Fault
d. the Mariana Arc
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14. A divergent boundary at two continental plates can result
in a(n)
a. mountain range.
b. rift valley.
c. island arc.
d. volcanic arc.
15. A convergent boundary occurs where
a. the Red Sea and Africa meet.
b. India and Asia meet.
c. the North American plate meets the Pacific plate.
d. the United States meets Canada.
16. The islands of Java and Sumatra in Indonesia are an
example of
a. a rift zone.
b. a hot spot.
c. an ocean ridge.
d. a volcanic island arc.
17. What is the main source of downward convection
movement in the mantle?
a. ridge-pull
b. ridge-push
c. slab-push
d. slab-pull
18. The downward sliding characteristic of ridge-push is the
result of
a. uneven heat distribution.
b. paleomagnetism.
c. gravity.
d. seafloor spreading.
19. According to the whole-mantle model of mantle convection,
a. small amounts of material from the mantle move upward
to the surface.
b. slabs of cold oceanic crust move down and into the lower
mantle.
c. large chunks of continental crust are pulled down into the
lower mantle.
d. material from the core-mantle boundary rises into the
mantle to form mantle plumes.
20. What causes the thermal convection that drives plate
motion?
a. seafloor spreading
b. differences in temperature and density
c. gravity
d. subduction
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Completion
Complete each statement on the line provided.
1. Alfred Wegener hypothesized that was
broken apart by the process of continental drift.
2. Wegener first began to think about his continental drift hypothesis
when he noticed a similarity in on different
continents.
3. One type of evidence that supports Wegener’s continental drift
hypothesis is the existence of that begin on
one continent and continue on another.
4. Layers of found in Africa, South America,
India, and Australia help to support the continental drift
hypothesis.
5. Interpreting Graphics Figure 1 shows the supercontinent
Pangaea. Identify each of the labeled landmasses.
A
B
C
D
E
F
G
6. Seafloor spreading begins when rises
upward toward the lithosphere.
7. A subduction zone occurs when one plate is
forced beneath a second plate.
8. The largest of the lithospheric plates covers most of the
Ocean.
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9. are produced by lithospheric plates
interacting at convergent boundaries.
10. The type of plate boundary shown in Figure 1 is a(n)
.
11. The plate boundary shown in Figure 2 results in the formation of
new .
12. At boundaries, oceanic lithosphere plunges
beneath an overriding lithospheric plate.
13. The islands of Java and Sumatra in Indonesia are an example of
a(n) .
14. Slab-pull occurs because oceanic crust sinks into the
15. The driving force behind plate movement is the process of
occurring in the mantle.
16. The primary forces that cause plate motion are made possible by a
mechanism called .
17. The appearance of at Earth’s
surface is evidence of mantle plumes.
Short Answer
In complete sentences, write the answers to the questions on the lines
provided.
1. Applying Concepts Summarize Alfred Wegener’s hypothesis
about past movements of the continents.
2. Predicting Using what you know about plate boundaries, explain
the tectonic movement that is occurring at the East African Rift
valley and predict how the area will change in the future.
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3. Comparing and Contrasting Discuss the similarities and
differences between oceanic-oceanic and continental-continental
convergent boundaries.
4. Applying Concepts Summarize the whole-mantle convection
model used for explaining plate motion.
Essay
In complete sentences, write the answer to the question on the lines provided.
1. Earth as a System Explain the tectonic processes involved in
seafloor spreading. At what type of plate boundary do these
processes occur?
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