Study Guide
Chapter 7
Plate Tectonics
1. Continental Drift
2. plate
3. seafloor spreading
4. Convergent plate boundary
5. paleomagnetism
6. plate tectonics
7. normal polarity
8. divergent plate boundary
9. hot spot
10. Pangaea
11. subduction zone
12. rift (rift valley)
13. transform boundary
14. polar wandering
15 reverse polarity
16. volcanic island arc
17. deep ocean trench
Comprehensive Review
1. a. fit of the continents
b. similar fossils on different land masses
c. similar rock types and structures on different
land masses
d. similar evidence of ancient climates on different
land masses
2. One of the main objections to Wegener’s
continental drift hypothesis was his inability to
provide a mechanism that was capable of moving
continents around the globe.
3. a) C
b) A
c) B
4. The theory of plate tectonics holds that the
Earth’s rigid outer shell consists of about 20
rigid slabs called plates that are in
continuous slow motion relative to each
other. These plates interact in various ways
and thereby produce earthquakes, volcanoes,
mountains and the crust itself.
5. 1. oceanic -continental convergence
2. Oceanic- oceanic convergence
3. continental- continental convergence
6. a. Paleomagnetism is used to show that the
continents have moved through time and,
using the pattern of magnetic reversals
found on the ocean floors, to explain sea
floor spreading.
b. Earthquake patterns are used to show
plate boundaries and to trace the descent
of slabs into the mantle.
c. Ocean drilling has shown that the ocean
basins are geologically youthful and
confirms sea floor spreading by the fact
that the age of the deepest ocean is
younger than continents. Crust is
younger near the spreading center,
increases with age toward the continents.
Sediment increases with increasing
distance from the ridge.
7. a) D
b) B
c) C
d) E
8. According to the Plate Tectonics theory, the
Appalachians formed as two plates, each with
continental lithosphere collided. Plates folded
and faulted and deformed into mountains.
9. A. Ridge push and slab pull hypothesis: as
new ocean crust moves away from the ridge,
it cools, increases in density and eventually
descends, pulling the trailing lithosphere
along
3 hypothesis for plate movement
Mantle convection
Ridge push
Slab pull
10. a) F
b) B
c) C
d) E
e) A
f) D
g) G
11. Examples of volcanic island arcs
Japan
Aleutian Islands
Tonga Islands
Lesser Antilles
Philippines
12. Four examples of folded faulted mountains:
Alps
Himalayas
Appalachians
Urals
13 List two examples of continental volcanic
arcs
Andes
Cascades
14 give an example of a transform boundary
San Andreas Fault
Earth is about 4.6 billion years old
Subcontinents: Laurasia, Gondwanaland