Pt
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Name:_____________________________________ Period:________ Date:_________________
SG
Ch 4 Study Guide
Multiple Choice
Write the letter of the correct answer on the line at the left.
______ 1. A break in Earth’s crust where rocks have slipped past each
other is called a
a. plate.
b. layer.
c. boundary.
d. fault.
______ 2. Continental crust consists mainly of the rock
a. nickel.
b. basalt
c. mantle.
d. granite.
______ 3. Scientists rejected Wegener’s theory because he could not
a. explain why continental crust was denser than oceanic crust.
b. describe the climate of Pangaea.
c. explain what force pushes or pulls continents.
d. describe how seeds moved from Africa to South America.
______ 4. Subduction is
a. the process by which oceanic crust sinks beneath trenches.
b. the direct transfer of heat through solid materials.
c. the process that continually adds ocean floor.
d. a device that bounces sound waves off underwater objects.
______ 5. Earth’s lithosphere is broken into separate sections called
a. plates.
b. faults.
c. trenches.
d. rifts.
______ 6. Scientists who study the forces that make and shape the
planet Earth are called
a. biologists.
b. geologists.
c. chemists.
d. physicists.
______ 7. In the convection current of a pan of soup, the cooler,
denser fluid
a. rises to the top.
b. sinks to the bottom.
c. stays where it is. d. stays on top.
______ 8. The transfer of energy through empty space is called
a. subduction.
b. convection.
c. radiation.
d. conduction.
______ 9. Who first proposed the theory of continental drift?
a. Harry Hess
b. Alfred Wegener
c. Pangaea
d. J. Tuzo Wilson
______ 10. What erupts through the valley of the mid-ocean ridge?
a. molten material
b. the lithosphere
c. deep-ocean trenches
d. continental drift
Completion
Fill in the line to complete each statement.
11. Heat transfer by the movement of a heated fluid is called
_Convection_.
12. A_Transform_ boundary is a place where two plates slip past each
other.
13. The _Asthenosphere_is the part of the mantle that can bend like
plastic.
14. The process that continually adds new material to the ocean floor
is_Sea Floor Spreading_.
15. Fossils of tropical plants found on an island in the Arctic Ocean
are evidence for the theory of _Plate tectonics/Continental drift_.
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Name:_____________________________________ Period:________ Date:_________________
True or False
If the statement is true, write true. If it is false, change the underlined
word or words to make the statement true.
_F- divergent_ 16. A rift valley forms along a convergent
boundary on land.
F- Pangaea_ 17. The supercontinent that began to break apart
about 225 million years ago is called Antarctica.
__T_____________ 18. As oceanic crust moves away from the midocean ridge, it cools and becomes more dense.
_T______________ 19. Density is a measure of how much mass
there is in a volume of a substance.
__F- Crust_ 20. The lithosphere includes all of the core and
part of the mantle.
Interpreting Data
23. Classifying Classify each of the plate boundaries shown on the
figure and identify the type of boundary not shown.
A- divergent boundary, sea floor spreads from this boundary
Convergent boundary- where the continental crust and oceanic crust
meet and the oceanic plate is subducted or pushed under the
continental plate.
Transform boundary is not shown.
24. Explain what sets convection currents into motion.
Heat from the core makes rock in the lower mantle hotter and less
dense, which causes it to rise and the cooler more dense rock of the
upper mantle falls.
21. Name each of the layers on the figure in order, from outermost to
innermost along with one major quality for each.
Crust- rigid solid rock
Mantle- plastic layer of rock
Outer Core- liquid iron and nickel
Inner Core- solid iron
22. Which layer(s) are not shown in the diagram and identify one
major quality of each.
Lithosphere- Lower part of the crust that floats on the asthenosphere.
Asthenosphere- convection currents in the asthenosphere cause plate
tectonics.
25. Describe the process of sea-floor spreading.
Convections currents in the mantle pulls the sea floor apart and molten
material rises up through the crack pushing the older crust to the side.
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Name:_____________________________________ Period:________ Date:_________________
26. Compare and contrast three different kinds of convergent boundaries.
Oceanic- continental: More dense oceanic crust is subducted under the continental crust, melts, & rises causing volcanic mountains to
form on the continent.
Oceanic- oceanic: The more dense plate is subducted, melts, & rises causing a volcanic island arc.
Continental- continental: Neither plate gets subducted, instead, they crumple up causing a chain of large folded mountains.
27. Describe what scientists now know about Earth that would have answered the scientists who rejected Wegener’s theory.
The evidence from sea floor spreading shows the force or mechanism that drives continental movement. That evidence comes in the form of molten
material, magnetic stripes, and drilling samples.
28. What accounts for the difference in density between oceanic and continental crust?
Oceanic crust has a lot of iron and other metals in it that continental crust does not have as much of. The metals are more dense than
the other materials that make up continental rocks.
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