Name ___________________________ Class ___________________ Date _____________
Chapter 9 Plate Tectonics
Study Guide
Multiple Choice
Write the letter that best answers the question or completes the statement.
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.
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
c. a volcano chain
b. a rift valley
d. a mountain range
6. What forms when one oceanic plate is forced beneath another plate?
a. an ocean basin
c. a subduction zone
b. ocean ridges
d. a rift valley
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.
Name ___________________________ Class ___________________ Date _____________
Chapter 9 Plate Tectonics
Study Guide
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
c. 5 cm per year
b. 50 in. 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
c. transform fault boundary
b. convergent boundary
d. transitional boundary
13. Which of the following is a geographic example of a transform fault boundary?
a. the East African Rift valley
c. the San Andreas Fault
b. the Mid-Atlantic Ridge
d. the Mariana Arc
14. A divergent boundary at two continental plates can result in a(n)
a. mountain range.
c. island arc.
b. rift valley.
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.
c. an ocean ridge.
b. a hot spot.
d. a volcanic island arc.
17. What is the main source of downward convection movement in the mantle?
a. ridge-pull
c. slab-push
b. ridge-push
d. slab-pull
18. The downward sliding characteristic of ridge-push is the result of
a. uneven heat distribution.
c. gravity.
b. paleomagnetism.
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.
Name ___________________________ Class ___________________ Date _____________
Chapter 9 Plate Tectonics
Study Guide
20. What causes the thermal convection that drives plate motion?
a. seafloor spreading
c. gravity
b. differences in temperature and density
d. subduction
Pangaea
coast lines
mountain belts
glacial till
North America
Eurasia
South America
Africa
India
Antarctica
Australia
magma
oceanic
Pacific
trenches
volcanoes
mountain ranges
divergent boundary
seafloor
convergent
Volcanic island arc
asthenosphere
convection
slab-pull
volcanoes
Completion
Complete each statement using the word bank 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 ___________________
Name ___________________________ Class ___________________ Date _____________
Chapter 9 Plate Tectonics
Study Guide
Figure 1
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.
9. ______________ , _______________ , and _______________
lithospheric plates interacting at convergent boundaries.
____________ are produced by
10. The type of plate boundary shown in Figure 2 is a(n) __________________ _________________ .
11. The plate boundary shown in Figure 2 results in the formation of new ____________________ .
Figure 2
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 _____________________ .
Name ___________________________ Class ___________________ Date _____________
Chapter 9 Plate Tectonics
Study Guide
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.
1. 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.
1. Earth as a System Explain the tectonic processes involved in seafloor spreading. At what type of plate
boundary do these processes occur?