GEOL, 2nd Edition solutions manual and test bank by Reed Wicander | James S. Monroe

GEOL, 2nd Edition solutions manual and test bank by Reed Wicander | James S. Monroe

Chapter 2—Plate Tectonics: A Unifying Theory

ESSAY

1. What were the major lines of evidence for continental drift as presented by Wegener in the early 20^th century?

ANS:

The glaciations on the Gondwana continents could only have occurred if the continents were joined, since the centers of the glaciers would have been in the ocean if they were not. Also, the continents, such as South America and Africa, match like a jigsaw puzzle. Fossil plant and animals are separated by oceans, when the organisms must have lived in adjacent regions when they were alive. Finally, similar rock sequences and mountain ranges could be connected across oceans.

PTS: 1 REF: LO1 Early Ideas About Continental Drift

2. Explain how mountain ranges can be used as evidence to support continental drift.

ANS:

A mountain range forms under the same geological conditions along its length. This means that the same or nearly the same rock types are found along the range's length in the same or nearly the same sequence. The processes that form mountain ranges tend to create somewhat linear elevated features. So a mountain range that has been split, even if it has been separated by an ocean, is fairly easy to recognize.

PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

3. How does fossil evidence support continental drift?

ANS:

The distribution of fossils is such that it would be impossible for the plants and animals not to have lived in contiguous land areas. Glossopteris seeds are too heavy to be dispersed by wind and would not have remained viable if they had traveled far across the oceans. The plants associated with Glossopteris do not match the climate zones the fossils are found in. As for the animals, it's hard to imagine a freshwater reptile like Mesosaurus swimming across the Atlantic. And the land-dwelling reptiles, Lystrosaurus and Cynognatuus, could not have swum at all!

PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

4. Why were glacially deposited strata important in the development of continental drift theory?

ANS:

The glacial deposits indicated that all southern continents must have been contiguous and closer to the south pole. Glaciers cannot form in the middle of an ocean, which is where they would have originated if the continents were not together.

PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

5. How is the phrase "the present is the key to the past" used in creating evidence for continental drift?

ANS:

Organisms probably lived in the types of environments where they live today, so a freshwater species would probably not be found in salt water and a seed that would now be too heavy to float in the atmosphere would have been too heavy in the past. Glaciers probably formed in the same environments that they do now and not in the middle of the ocean. Similar rock sequences probably indicate that the rocks are related to each other geologically and did not randomly generate the same sequence.

PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

6. Explain why submarine hydrothermal vents are interesting to scientists.

ANS:

Vents are interesting for biological, geological and economic reasons. Although nearly all of Earth’s organisms directly or indirectly rely on photosynthesis for food, vent organisms rely on bacteria that break down sulfur compounds for nutrients. Metal-rich fluids flow out of vents and form chimney-like structures. The chimneys are full of metals that have economic value.

PTS: 1 REF: LO3 Features of the Seafloor

7. Briefly explain why apparent polar wandering is "apparent".

ANS:

Paleomagnetic studies of ancient rocks point to different locations for the north pole at different times. When this is mapped out, it makes the pole appear to wander over time. The alternative to a wandering magnetic pole, for which there is no other evidence at all, is that the continents move and, with them, the rocks that contain the paleomagnetic data.

PTS: 1 REF: LO5 Paleomagnetism and Polar Wandering

8. Briefly explain why the movement of continents over geologic time was the best explanation for polar wandering.

ANS:

Since the Earth has only one magnetic north pole now, it is extremely unlikely that there would have been more than one in the past, but this would have been required to explain the different polar wander paths of the different continents. The only other possible explanation is that the continents were once joined and have since moved.

PTS: 1 REF: LO5 Paleomagnetism and Polar Wandering

9. How does seafloor spreading explain the movement of the continents?

ANS:

With seafloor spreading, the continents and oceanic crust move together as part of large plates. The plate is pushed by the formation of new ocean crust and pulled by the subduction of old ocean crust. New crust forms due to seafloor spreading.

PTS: 1 REF: LO6 Magnetic Reversals and Seafloor Spreading

10. Briefly explain how magnetic reversals in oceanic crust and fossils in ocean sediments are used to construct a magnetic time scale.

ANS:

A terrestrial sequence of magnetic reversal in volcanic deposits was dated radiometrically. These dates were extrapolated to regions which were not dated, but showed the same pattern of normal and reversed magnetic polarities. Ages of ocean-floor basalts lying within a zone of normal or reversed polarity are dated by the ages of the fossils found in the sediments that directly overlie the basaltic crust. These fossils have already been incorporated within a biostratigraphic zone.

PTS: 1 REF: LO6 Magnetic Reversals and Seafloor Spreading

11. Briefly describe what happens when divergent plate boundaries form within a continent.

ANS:

High heat flow elevates the continent and a rift valley forms, with normal faults and a central valley called a graben. Magma is intruded into fractures. As the plates diverge, basalt erupts in the rift, creating new ocean crust. Ultimately, as the plates continue to diverge, a new ocean basin forms.

PTS: 1 REF: LO8 The Three Types of Plate Boundaries

12. Draw a cross-section of an oceanic-oceanic convergent plate boundary. Show the directions of relative plate motion. Put stars for the locations of earthquakes. Put triangles with smoke out the top for the locations of volcanoes. Label the trench, back arc basin, and subduction complex.

ANS:

See Figure 2.19a.

PTS: 1 REF: LO8 The Three Types of Plate Boundaries

13. What are four of the many things that plate tectonics theory explains or whose explanations it has influenced?

ANS:

Plate tectonics explains, at least to some extent, all of the following phenomena: the distribution of earthquakes and volcanoes, the locations of ore deposits and mountain systems, climate and ocean circulation patterns, and the geographic distribution, evolution and extinction of life forms.

PTS: 1 REF: LO8 The Three Types of Plate Boundaries

14. Draw a cross-section of an oceanic-continental convergent plate boundary. Show the directions of relative plate motion. Put stars for the locations of earthquakes. Put triangles with smoke out the top for the locations of volcanoes. Label the trench and subduction complex.

ANS:

See Figure 2.19b.

PTS: 1 REF: LO8 The Three Types of Plate Boundaries

15. Draw a cross-section of a continental-continental convergent plate boundary. Show the directions of relative plate motion. Put stars for the locations of earthquakes. Show the location of the mountain range. Label the subduction complex.

ANS:

See Figure 2.19c.

PTS: 1 REF: LO8 The Three Types of Plate Boundaries

16. How are hot spots used for determining the absolute motions of plates?

ANS:

Hot spots appear to be fixed in the mantle relative to each other, so they can be used as a reference frame. If the age of a basalt and its distance from the hot spot is determined, then the rate of movement of that rock can be calculated. If a number of these samples are taken from various distances from the hot spot, the calculation can be quite accurate.

PTS: 1 REF: LO9 Hot Spots and Mantle Plumes

17. What is a method by which the present rate of motion between two plates can be measured accurately?

ANS:

The travel of a laser beam can be timed from one plate to another by bouncing it from a satellite and by calculating the difference in arrival times of a quasar signal at two plates over a period of time.

PTS: 1 REF: LO10 Plate Movement and Motion

18. Briefly explain why there is so much oil in the Persian Gulf region.

ANS:

During the Mesozoic, the Persian Gulf was a broad, stable marine shelf. Countless microorganisms lived in the surface water and their remains accumulated in the bottom sediments and were buried. The collision between Arabia and Iran has tilted the Arabian plate and crumpled rocks on the edges of both plates. The tilting of Arabia allows oil to migrate upslope to accumulate in traps created by folding.

PTS: 1 REF: LO12 Plate Tectonics and the Distribution of Natural Resources

19. Briefly explain the roles of magma and hydrothermal activity in forming ore deposits along convergent and divergent plate boundaries.

ANS:

Magma contains valuable elements, some of which leave the magma in gases and fluids. These substances transport the elements and facilitate their exchange for other elements in the surrounding rock. The surrounding rock may then have enough of the valuable elements to become an ore deposit. At convergent plate boundaries, partial melting at the subducting plate allows magma and valuable minerals to rise up in fluids and erupt at volcanoes or cool beneath the surface as plutons. At divergent plate boundaries, hydrothermal vents form. In these locations, seawater filters past hot magma, picks up valuable elements, and then the hot fluids flow onto the seafloor and drop their valuable elements.

PTS: 1 REF: LO12 Plate Tectonics and the Distribution of Natural Resources

20. How does the introduction of a geographic barrier encourage the evolution of species?

ANS:

A population that is not separated will interbreed, so there will be little opportunity for different species to form. If a barrier separates that population and if conditions are different on either side of the barrier, natural selection will favor certain traits over others, and over time the two different populations of organisms may evolve to become different species.

PTS: 1 REF: LO13 Plate Tectonics and the Distribution of Life

SHORT ANSWER

1. Who was the first person to suggest that all of the continents had been once joined together as a supercontinent called Pangaea and when was that idea proposed?

ANS:

The German meteorologist Alfred Wegener proposed the existence of Pangaea in 1915.

PTS: 1 REF: LO1 Early Ideas About Continental Drift

2. What do glacial striations indicate?

ANS:

Glacial striations indicate the general direction that a glacier was moving.

PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

3. Where is the best place to try to fit the continents together?

ANS:

Along the continental slope at a depth of 2000 m.

PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

4. List two ways that glacial deposits give strong evidence of the existence of Gondwana.

ANS:

Without Gondwana, the glaciers would have been at a much lower latitude than glaciers are found today, and the glacial striations indicated that the ice flowed from a central location rather than from a separate glacier on each continent.

PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

5. Why were glacially deposited strata important in the development of the continental drift hypothesis?

ANS:

The glacial deposits indicated that all of the southern continents were once closer to the south pole and were contiguous.

PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

6. The Appalachian Mountains of the eastern United States are thought to have once been joined with mountains located in which other continental regions?

ANS:

Canada, eastern Greenland, Ireland, Great Britain, and Norway.

PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

7. What is the reason that the presence of Glossopteris flora fossils was strong evidence for the existence of Gondwana?

ANS:

The seeds of the Glossopteris ferns could not have been carried long distances by wind or water, so the plants must have lived on adjacent lands.

PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

8. What is the principal reason why Wegener's hypothesis of continental drift was rejected?

ANS:

Wegener lacked a plausible mechanism to explain how continental crust could move through the sea floor.

PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

9. What other geological processes could have resulted in the configuration of coastlines so that South America and Africa appeared to fit together?

ANS:

Wegener's critics pointed out that erosional and depositional processes could have created that configuration of the coastlines.

PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

10. What are the three possible explanations for the distribution of paleomagnetic data?

ANS:

(1) The continent remained fixed, and the north magnetic pole moved; (2) the north magnetic pole stayed still, and the continent moved; (3) both the continent and north magnetic pole moved.

PTS: 1 REF: LO5 Paleomagnetism and Polar Wandering

11. What is it about a cooling lava that allows geologists to determine the location of past magnetic poles?

ANS:

Iron-bearing minerals in a cooling lava align themselves in the direction of the current magnetic field as they cool below the Curie Point.

PTS: 1 REF: LO5 Paleomagnetism and Polar Wandering

12. What two features of the magnetic field do magnetic iron-bearing minerals that crystallize out of magma record?

ANS:

The minerals record the strength and direction of the Earth's magnetic field at the time of crystallization.

PTS: 1 REF: LO5 Paleomagnetism and Polar Wandering

13. What evidence is there that ocean basins are young and old oceanic crust must be destroyed?

ANS:

The maximum age for oceanic crust is 180 million years, but the continents contain rocks both younger and much older than 180 million years. The older oceanic crust must go somewhere.

PTS: 1 REF: LO6 Magnetic Reversals and Seafloor Spreading

14. Where in the ocean basins is ocean crust youngest?

ANS:

At the crests of the mid-oceanic ridges.

PTS: 1 REF: LO6 Magnetic Reversals and Seafloor Spreading

15. Why is plate tectonic theory so widely accepted?

ANS:

Plate tectonic theory is supported by diverse lines of evidence from many scientific disciplines, such as geology and biology, and it explains many seemingly unrelated geological phenomena.

PTS: 1 REF: LO7 Plate Tectonics: A Unifying Theory

16. What type of motion is found at a transform plate boundary? What physical feature marks the boundary between the two plates?

ANS:

At a transform plate boundary two plates slide laterally past each other. A transform plate boundary is the site of a transform fault.

PTS: 1 REF: LO8 The Three Types of Plate Boundaries

17. What is a hot spot relative to a mantle plume? What is often found there?

ANS:

A hot spot is the location where a mantle plume rises to Earth’s surface. A volcano often forms above a hot spot.

PTS: 1 REF: LO9 Hot Spots and Mantle Plumes

18. What is the driving mechanism for plate tectonics?

ANS:

Thermal convection cells.

PTS: 1 REF: LO11 The Driving Mechanism of Plate Tectonics

19. Briefly explain how convection transfers heat.

ANS:

When a material is heated, it expands. Its density decreases, so it rises. After having risen some distance, it begins to cool, contract, and become denser. Thus, the material sinks and returns to the original level, where it will eventually be heated and rise again.

PTS: 1 REF: LO11 The Driving Mechanism of Plate Tectonics

20. In what ways does plate tectonics theory have economic applications?

ANS:

By understanding the geologic history of a region, geologists can predict whether it will be a worthwhile place to search for petroleum or ore deposits.

PTS: 1 REF: LO12 Plate Tectonics and the Distribution of Natural Resources

COMPLETION

1. Wegener proposed that the continents were once all together as a supercontinent he named ____________________, which then split into a northern supercontinent called ____________________ and a southern supercontinent called ____________________.

ANS: Pangaea, Laurasia, Gondwana

PTS: 1 REF: LO1 Early Ideas About Continental Drift

2. The group of plant fossils that provides important evidence for the existence of Gondwana is ____________________.

ANS: Glossopteris

PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

3. At deep-sea trenches, ____________________ is subducted back into the ____________________.

ANS: lithosphere, mantle

PTS: 1 REF: LO3 Features of the Seafloor

4. The physical phenomenon that results from the spin of electrons that is found in some solids, particularly iron, and moving electricity is known as ____________________. The zone around substances with this property is called a ____________________.

ANS: magnetism, magnetic field

PTS: 1 REF: LO4 Earth's Magnetic Field

5. Paleomagnetism is the study of the ____________________ magnetism in rocks. When magma cools, the magnetic iron-bearing minerals align themselves with the Earth's magnetic field and record ____________________ and ____________________.

ANS:

remnant, strength, direction

remnant, strength, direction f the north pole

remnant, direction, strength

remnant, direction of the north pole, strength

PTS: 1 REF: LO5 Paleomagnetism and Polar Wandering

6. The temperature at which iron-bearing minerals gain their magnetic property is the ____________________.

ANS: Curie point

PTS: 1 REF: LO5 Paleomagnetism and Polar Wandering

7. Paleomagnetic data plotted on a map suggested that the magnetic pole had moved over time; this phenomenon was called ____________________.

ANS: polar wandering

PTS: 1 REF: LO5 Paleomagnetism and Polar Wandering

8. At mid-oceanic ridges, hot magma rises from the ____________________ and forms new ____________________.

ANS: mantle, seafloor

PTS: 1 REF: LO6 Magnetic Reversals and Seafloor Spreading

9. Magnetic stripes in oceanic basalts are ____________________ and ____________________ around ocean ridges.

ANS:

parallel, symmetrical

symmetrical, parallel

PTS: 1 REF: LO6 Magnetic Reversals and Seafloor Spreading

10. Radiometric dating shows that the oldest ocean crust is ____________________ years old and the oldest continental crust is ____________________ years old.

ANS: 180 million, 3.96 billion

PTS: 1 REF: LO6 Magnetic Reversals and Seafloor Spreading

11. Deviations from the average strength of Earth’s present-day magnetic field are called ____________________.

ANS: magnetic anomalies

PTS: 1 REF: LO6 Magnetic Reversals and Seafloor Spreading

12. At divergent plate boundaries, plates are moving ____________________. At these locations, new ____________________ forms.

ANS: apart, lithosphere

PTS: 1 REF: LO8 The Three Types of Plate Boundaries

13. Where divergent plate boundaries form beneath continental masses, low areas known as ____________________ form.

ANS: rift valleys

PTS: 1 REF: LO8 The Three Types of Plate Boundaries

14. At a convergent plate boundary, oceanic crust is ____________________.

ANS: destroyed

PTS: 1 REF: LO8 The Three Types of Plate Boundaries

15. Volcanoes are found at these two types of plate boundaries: ____________________ and ____________________.

ANS:

divergent, convergent

convergent, divergent

PTS: 1 REF: LO8 The Three Types of Plate Boundaries

16. The type of plate boundary that runs through California is called ____________________, and the name of this plate boundary is the ____________________.

ANS: transform, San Andreas Fault

PTS: 1 REF: LO8 The Three Types of Plate Boundaries

17. Rock sequences found on land that consist of deep-sea sediment, oceanic crust, and upper mantle are called ____________________. These sequences are used to identify ____________________ plate boundaries.

ANS: ophiolites, convergent

PTS: 1 REF: LO8 The Three Types of Plate Boundaries

18. The process that continues to move Africa and South America apart from each other is ____________________.

ANS: seafloor spreading

PTS: 1 REF: LO10 Plate Movement and Motion

19. The heat that drives thermal convection cells comes primarily from ____________________ and is supplemented by ____________________.

ANS: the core, radioactive decay

PTS: 1 REF: LO11 The Driving Mechanism of Plate Tectonics

20. Most of the petroleum found in the Persian Gulf area formed at a ____________________ continental margin where the remains of ____________________ were buried and converted to petroleum.

ANS: passive, microorganims

PTS: 1 REF: LO12 Plate Tectonics and the Distribution of Natural Resources

MULTIPLE CHOICE

1. Plate tectonic processes have influenced:

a.	the distribution of earthquakes and volcanoes.
b.	the locations of ore deposits and mountain systems.
c.	climatic patterns and ocean circulation.
d.	the geographic distribution, evolution, and extinction of life forms.
e.	all of these

ANS: E PTS: 1 REF: various

2. That the northern continents were once joined and located along the equator was shown by the:

a.	coal-age plant fossils of North America and Europe.
b.	Glossopteris flora.
c.	distribution of mountain ranges.
d.	distributions of Permian and Triassic reptiles.
e.	distributions of northern hemisphere glacial tillites.

ANS: A PTS: 1 REF: LO1 Early Ideas About Continental Drift

3. The northern supercontinent consisted of:

a.	North America, Europe, Asia, India, and Greenland.
b.	North America, Greenland, and Europe.
c.	North America, Europe, Asia, and India.
d.	North America, Greenland, Asia, and India.
e.	North America, Europe, Asia, and Greenland.

ANS: E PTS: 1 REF: LO1 Early Ideas About Continental Drift

4. Fossil evidence linking the Gondwana continents includes the:

a.	lake-dwelling Mesosaurus and large land-dwelling reptile Lystrosaurus and Cynognathus.
b.	freshwater Mesosaurus and dinosaurs Brontosaurus and Tyrannosaurus.
c.	freshwater crocodiles and the large amphibian Eryops.
d.	reptile Dimetrodon and the first bird Archaeopteryx.
e.	lake-dwelling Mesosaurus and the large land-dwelling reptiles Dimetrodon and Edaphosaurus.

ANS: A PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

5. Fossil evidence of the links among Gondwana continents was compelling because the species should have:

a.	been found over wide regions if they were able to migrate among continents.
b.	exhibited evidence of tolerance for climatic extremes.
c.	shown a mechanism for widespread dispersal.
d.	been found over wide regions and shown a mechanism for widespread dispersal.
e.	been found over wide regions, exhibited evidence of tolerance for climatic extremes and shown a mechanism for widespread dispersal.

ANS: E PTS: 1 REF: LO2 What is the Evidence for Continental Drift?

6. Studies of paleomagnetism document:

a.	changes in the Earth's gravitational field.
b.	how the inner/outer core boundary has evolved.
c.	how the mineral magnetite has varied through time.
d.	how the Earth's magnetic poles have varied through time.
e.	none of these

ANS: D PTS: 1 REF: LO5 Paleomagnetism and Polar Wandering

7. The study of paleomagnetism is possible because:

a.	the magnetic minerals in rocks create the Earth's magnetic field.
b.	most rocks contain no magnetic minerals.
c.	the magnetic minerals in rocks disrupt the Earth's magnetic field.
d.	the magnetic minerals in a cooling lava point toward the north magnetic pole.
e.	none of these

ANS: D PTS: 1 REF: LO5 Paleomagnetism and Polar Wandering

8. The differing paleomagnetic records for each continent showed:

a.	each continent had its own magnetic pole during successive geological periods.
b.	that the magnetic poles for each continent had moved over geological time.
c.	that the magnetic poles have remained in one location and each of the continents has moved.
d.	that both the poles and the continents have moved over time.
e.	none of these

ANS: C PTS: 1 REF: LO5 Paleomagnetism and Polar Wandering

9. The symmetrical pattern of magnetic polarities about spreading ridges in oceanic crust basalts indicates that:

a.	each plate has had an independent set of magnetic reversals.
b.	basalt retains its magnetic signature for only a few million years.
c.	new ocean crust is created by volcanism at oceanic ridges and old crust moves laterally away from the ridge.
d.	the oceanic crust is geologically young.
e.	magnetic polarity reverses but northern and southern hemispheres do not.

ANS: C PTS: 1 REF: LO6 Magnetic Reversals and Seafloor Spreading

10. At divergent plate boundaries, the operating forces are:

a.	compressional.
b.	lateral shearing.
c.	tensional.
d.	thrusting.
e.	normal.

ANS: C PTS: 1 REF: LO8 The Three Types of Plate Boundaries

11. At a mid-oceanic ridge spreading center:

a.	the plates are moving past each other.
b.	the plates are moving away from each other.
c.	the plates are moving toward each other.
d.	one plate is being subducted beneath another.
e.	both plates are being subducted.

ANS: B PTS: 1 REF: LO8 The Three Types of Plate Boundaries

12. Which are not associated with a mid-oceanic ridge?

a.	old ocean crust
b.	shallow-depth earthquakes
c.	volcanic eruptions
d.	transform faults
e.	hot water

ANS: A PTS: 1 REF: LO8 The Three Types of Plate Boundaries

13. Large, high mountain ranges without volcanoes are built at which type of plate boundary?

a.	divergent: oceanic-oceanic
b.	convergent: oceanic-continental
c.	convergent: continental-continental
d.	transform: continental-continental
e.	divergent: oceanic-oceanic AND convergent: continental-continental

ANS: C PTS: 1 REF: LO8 The Three Types of Plate Boundaries

14. A transform plate boundary may connect:

a.	a spreading ridge and subduction zone.
b.	two spreading ridges.
c.	two subduction zones.
d.	a spreading ridge and a subduction zone or two subduction zones.
e.	a spreading ridge and a subduction zone, two spreading ridges, or two subduction zones.

ANS: E PTS: 1 REF: LO8 The Three Types of Plate Boundaries

15. The mechanism for plate movement is:

a.	conduction of heat from the core.
b.	friction created by tidal forces generated by the Moon.
c.	conduction of heat within the mantle.
d.	convection of heat within the mantle.
e.	convection of heat within the core.

ANS: D PTS: 1 REF: LO11 The Driving Mechanism of Plate Tectonics

TRUE/FALSE

1. The 2005 Indian Ocean tsunami, the eruption of Mount Merapi in 2010 and the 9.0 magnitude earthquake that struck Japan in 2011 occurred at the same type of plate boundary.

ANS: T PTS: 1 REF: Introduction

2. Around most of the Atlantic the continental slope descends into an oceanic trench but around the Pacific the continental slope merges with a more gently sloping continental rise.

ANS: F PTS: 1 REF: LO3 Features of the Seafloor

3. Aseismic ridges have that name because they do not have earthquakes.

ANS: T PTS: 1 REF: LO3 Features of the Seafloor

4. Earth’s magnetic field is dipolar, meaning that it has two similar magnetic poles one at the north pole and one at the south pole.

ANS: F PTS: 1 REF: LO4 Earth's Magnetic Field

5. A rock will preserve its remnant magnetism as long as it is not heated above the Curie point.

ANS: T PTS: 1 REF: LO5 Paleomagnetism and Polar Wandering

6. Changes in the Earth's magnetic field have occurred throughout geologic time, and these are called magnetic reversals.

ANS: T PTS: 1 REF: LO6 Magnetic Reversals and Seafloor Spreading

7. The cause of magnetic reversals is a change in the structure of the Earth's inner core.

ANS: F PTS: 1 REF: LO6 Magnetic Reversals and Seafloor Spreading

8. Paleomagnetic studies show that the ocean basins are older than the continents.

ANS: F PTS: 1 REF: LO6 Magnetic Reversals and Seafloor Spreading

9. Features associated with ancient continental rift zones include andesite volcanoes and strike slip faulting.

ANS: F PTS: 1 REF: LO8 The Three Types of Plate Boundaries

10. During the Triassic, a number of rift related fault basins formed along the eastern margin of North America.

ANS: T PTS: 1 REF: LO8 The Three Types of Plate Boundaries

11. There is a divergent plate boundary within the region of east Africa.

ANS: T PTS: 1 REF: LO8 The Three Types of Plate Boundaries

12. Hot spots move with continental plates.

ANS: F PTS: 1 REF: LO9 Hot Spots and Mantle Plumes

13. The subduction of cold, dense oceanic lithosphere into the mantle facilitates teh movement of plates by slab pull.

ANS: T PTS: 1 REF: LO11 The Driving Mechanism of Plate Tectonics

14. Copper deposits are most commonly found at transform plate boundaries.

ANS: F PTS: 1

REF: LO12 Plate Tectonics and the Distribution of Natural Resources

15. The diversity of organisms is highest where large continents are found stradding a latitude zone.

ANS: F PTS: 1 REF: LO13 Plate Tectonics and the Distribution of Life