Geology 110: Earth and Space Science
Chapter 4 (Plate Tectonics) Homework
SELF-REFLECTION AND COMPREHENSION SURVEYS
Checkpoint 4.1, p. 84
#1: Examine the following figure.
Which map best represents the current distribution of continents and oceans on Earth? What are the principal problems with the maps that are incorrect?
Label the continents and the three major oceans.
Checkpoint 4.2, p. 84
#2: Which of these lines of evidence were used to support Wegener’s continental drift hypothesis (select all that apply)?
a) The distribution of fossils
b) Fit of continents
c) Match of mountain belts
d) Earthquake locations
e) Paleoclimate data
Checkpoint 4.4, p. 86
#3: Write a paragraph that argues for or against the following statement:
Development of the hypothesis of continental drift was consistent with the characteristics of good science.
Checkpoint 4.5, p. 88
#4: After examining the diagram that follows, determine which pair of locations has oceanic trenches.
a) A, C b) D, F c) B, E d) G, H
Checkpoint 4.6, p. 88
#5: Regarding the relationship between age and the character of the ocean floor, which statement(s) is (are) TRUE?
a) Deeper regions of the ocean floor tend to be younger.
b) The Pacific is larger than the Atlantic because it contains older oceanic floor.
c) The oldest oceanic crust is present only near trenches.
d) The youngest oceanic crust is near the ridges.
Checkpoint 4.8, p. 90
#6b: Explain how the following patterns can be interpreted to contradict the contracting Earth model: (1) topography of the ocean floor, (2) age of the ocean floor, (3) heat flow, (4) volcanic activity, and (5) earthquake activity in the ocean floor.
Checkpoint 4.9, p. 92
#9: Which United States’ location has the greatest magnetic inclination value (that is, closest to vertical)?
a) Anchorage, Alaska b) New York, New York c) Miami, Florida d) Imperial, California
Checkpoint 4.11, p. 92
#7: Inclination is determined for three lava flows preserved in a cliff as shown in the following image. What happened to the continent on which these rocks were formed? (Assume normal polarity throughout. Upper layers are youngest, lower layers are oldest. Note the inclination angle of the arrows from nearly horizontal in the bottom lava flow, to nearly vertical in the top lava flow, and the direction the arrows point from nearly horizontal to upwards: then think about the Earth’s magnetic field as shown on pages 91 and 92)
The rocks in the cliff moved toward the _______ in the ________ Hemisphere.
a) Equator; Southern c) Pole; Southern
b) Equator; Northern d) Pole; Northern
Checkpoint 4.12, p. 94
#8: Which magnetic property was more important in providing support for the seafloor spreading hypothesis? Explain the reasoning behind your choice of answer.
a) Magnetic inclination: the inclination of Earth’s magnetic field varies with location.
b) Magnetic polarity: the North and South magnetic poles have switched positions throughout Earth’s history.
Checkpoint 4.13, p. 98
#13: Draw the approximate location of the plate boundaries on the following map. Use different line symbols for the oceanic ridges and oceanic trenches. Name and label as many of the plates as you can.
Checkpoint 4.17, p. 106
#17: On the following map, the patterned areas labeled X, Y, and Z represent continents; assume the rest of the map is ocean.
How many plates are present? ________
a) 3 b) 4 c) 5 d) 6
Checkpoint 4.19, p. 106
#10: Venn Diagram: Divergent versus Convergent Plate Boundaries
Use the following Venn diagram to compare and contrast divergent and convergent plate boundaries. Three characteristics of plate boundaries are provided. Identify at least 7 more. Then write the numbers of the features unique to either group in the larger areas of the left and right circles; note features that they share in the overlap area in the center of the image.
1. Rocks on either side of boundary are typically of different ages.
2. Example: Nazca and South American plate boundary.
3. Associated with oceanic trenches.
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