Download Restless Continents Section Review

Name ______________________________ Class ___________________ Date __________________
Skills Worksheet
Section Review
Restless Continents
USING KEY TERMS
1.your own words, write a definition for each of the following terms: continental
drift and sea-floor spreading.
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UNDERSTANDING KEY IDEAS
_____ 2. At mid-ocean ridges,
a. the crust is older.
b. sea-floor spreading occurs.
c. oceanic lithosphere is destroyed.
d. tectonic plates are colliding.
3. Explain how oceanic lithosphere forms at mid-ocean ridges.
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4. What is magnetic reversal?
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MATH SKILLS
5. If a piece of sea floor has moved 50 km in 5 million years, what is the yearly
rate of sea-floor motion? Show your work below.
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Science and Technology
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Plate Tectonics
Name ______________________________ Class ___________________ Date __________________
Section Review continued
CRITICAL THINKING
6. Identifying Relationships Explain how magnetic reversals provide evidence for
sea-floor spreading.
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7 .Applying Concepts Why do bands indicating magnetic reversals appear to be
of similar width on both sides of a mid-ocean ridge?
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8 .Applying Concepts Why do you think that old rocks are rare on the ocean
floor?
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Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Science and Technology
33
Plate Tectonics