1. What force drives plate motion?

A. Mantle convection.

B. Tidal forces.

C. Centrifugal force.

D. Coriolis force.

E. Gravity.

2. Magnetic anomalies

A. form at the ridge crest.

B. have a mirror symmetry about the ridge crest.

C. match the pattern of magnetic reversals.

D. all of the preceding.

E. none of the preceding.

3. The Vine-Matthews hypothesis of magnetic anomaly origin

A. suggests that magnetic anomalies cause magnetic reversals.

B. requires the collision of an asteroid with Earth every 500,000 years.

C. can be used to predict the age of the sea floor.

D. suggests that the rift valley of the mid-oceanic ridge is caused by an expanding Earth.

E. explains how mantle plumes can break a continent in two.

4. The oldest rocks on the sea floor are about

A. 20 million years old.

B. 200 million years old.

C. 600 million years old.

D. 3 billion years old.

E. 4.5 billion years old.

5. The Emperor seamounts and the Hawaiian Islands appear to have formed as the Pacific floor passed over

A. an oceanic rise.

B. the core.

C. a trench.

D. a hot spot.

6. Beneath an oceanic trench, deep earthquake foci follow an inclined planar zone called

A. a Bearing zone.

B. a tsunami zone.

C. a Benioff zone.

D. an isostasy zone.

E. a Berghoff zone.

7. Horizontal movements of the Earth's crustal plates occurs at rates of

A. 0.01 to 0.1 cm/year.

B. 0.1 to 1.0 cm/year.

C. 1.0 to 20 cm/year.

D. 20 to 100 cm/year.

8. Lack of active volcanoes in the Himalayas today is consistent with

A. the observed lack of a Benioff Zone.

B. evidence for great crustal compression.

C. the presence of an active orogenic system.

D. the observed absence of an active spreading center near the mountains.

9. Island arc systems like the Aleutian arc are generally associated with __________ in plate tectonic theory

A. subduction.

B. reduction.

C. spreading.

D. transform slippage.

10. Along the San Andreas fault, plates are

A. separating.

B. slipping past each other.

C. colliding.

D. remaining stationary.

11. An example of the collision of two continental plates is the

A. Himalaya Range.

B. islands of Japan.

C. Mid-Atlantic Ridge.

D. Peru-Chile coast.

12. Andesitic volcanoes are found at

A. converging plate boundaries.

B. diverging plate boundaries.

C. the mid-oceanic ridge crest.

D. transform boundaries.

E. along fracture zones.

13. San Diego, California, and Baja California are part of which plate?

A. Pacific plate.

B. North American plate.

C. Southern California plate.

14. Most of the ground water pumped from water wells comes from

A. precipitation that soaks into the ground.

B. water that has been transpired by plants.

C. water released by nearby sources of magma.

D. the decomposition of organic debris in the ground.

15. What happens to the porosity as the grain size gets smaller?

A. It increases.

B. It remains unchanged.

C. It decreases.

16. Sinkholes are usually formed in areas

A. with limestone caverns.

B. where ground water is being pumped out of the ground too quickly.

C. underlain by shale.

D. with extensive irrigation systems.

17. Which of the following factors tends to delay the build up of the discharge of surface streams after a storm?

A. Extensive heavy vegetation.

B. Low permeability of surface rocks.

C. High topographic relief.

D. Extensive urban development.

18. An artesian well will flow if the

A. top of the well is at a lower elevation than that of the water table in the recharge area.

B. top of the well is at a higher elevation than that of the water table in the recharge area.

C. bottom of the well is at a lower elevation than that of the land surface in the recharge area.

D. bottom of the well is at a lower elevation than that of the water table in the recharge area.

19. A well is most likely to encounter a good supply of water at shallow depth in which situation?

A. In shale on a ridge top.

B. In shale on a valley bottom.

C. In granite on a ridge top.

D. In sandstone on a ridge top.

E. In sandstone on a valley bottom.

20. Where do rivers obtain their energy?

A. Heat.

B. Gravity.

C. Electricity.

D. Friction.

E. Radioactivity.

21. Building a dam on a river will probably result in

A. erosion upstream and downstream of the dam.

B. deposition upstream and downstream of the dam.

C. erosion upstream, deposition downstream.

D. deposition upstream, erosion downstream.

22. If a landslide partially dams a stream valley, the stream would

A. probably start to erode upstream of the landslide.

D. start to erode downstream to produce a steeper gradient so it could carry the extra load.

23. A stream running over which rock type would probably contain the greatest dissolved load?

A. Granite.

B. Basalt.

C. Marble.

D. Sandstone.

E. Shale.

24. Clay particles tend to be carried by a stream as part of the

A. dissolved load.

B. suspended load.

C. bed load.

D. none of these.

25. The entrenched meanders of a river, like the Colorado River through the Grand Canyon, are evidence for

A. an increase in stream velocity due to uplift of the land or increased rainfall.

B. a decrease in stream gradient.

C. a decrease in discharge.

D. an increase in load due to a large landslide somewhere upstream.

26. A meander cutoff increases a stream's

A. length.

B. discharge.

C. gradient.

D. width.

E. dissolved load.

27. Regional uplift and erosion may lead to the development of

A. stream terraces.

B. incised meanders.

C. accelerated downcutting in steams.

D. all of the above.

E. none of the above.

28. If the discharge of a stream increases (for example, during a flood), the capacity of the stream

A. decreases, but the competence increases.

B. stays the same, but the competence increases.

C. increases, but the competence decreases.

D. increases, and the competence increases.

29. If the base level of a stream is lowered

A. the stream will deposit to raise the base level to its former position.

B. the stream will begin to downcut at its headwaters.

D. a change in base level will have no effect on the stream.

30. The bending of waves as they approach shore is called

A. wave reflection.

B. wave erosion.

C. a longshore current.

D. coastal straightening.

E. wave refraction.

31. Points and headlands are eroded faster than inlets and bays along a coast because of

A. the more resistant rock in the headland.

B. wave refraction.

C. longshore drift.

D. wave reflection.

E. none of the above.

32. Longshore drift occurs because

A. people have built homes along most shorelines.

B. waves move faster as they get near the shore -- this is called refraction.

C. waves commonly approach the shoreline at an angle.

D. rivers carry sediment from the shoreline to greater water depths offshore.

E. tides tend to move sediments parallel to shorelines.

33. If a breakwater is built offshore from a sandy beach beyond the surf zone to provide safe harbor for boats, the

1. Ground water table / Spring

2. Ground water table / Perennial stream

3. Limestone / Caves / Karst topography

4. Meander bend / Bank erosion

5. Stream velocity / Stream discharge

6. Base level / Entrenchment

7. Urbanization / Stream entrenchment

1. Briefly explain the factors that can cause a river to deposit sediment.

2. Twenty years ago a family built a home adjacent to a small desert wash. In fact, they used the sandy bottom as a driveway and enjoyed the lush vegetation along its banks. Last year a large shopping center with many acres of paved parking lot was built upstream from this family's home. Exploring their wash, the kids walked right into the parking lot. What impact might this recent development have on their home? Discuss at least TWO.

3. Your parents have just purchased a summer home on the narrow floodplain of a small dry wash in the bottom of a beautiful canyon in northern Arizona. The sedimentary rocks in the canyon walls are all horizontal. In a neat, well-labeled diagram illustrating the setting described above, also show the following:

4. In his keynote address, "A Reverence for Rivers," Luna Leopold characterized a river as being "like an organism; it is internally self-adjusting." Explain what Leopold meant. Illustrate your discussion with an example, flow chart or diagram.

5. A beach can be characterized as a "river of sand." Discuss the following:

A. How is sand transported along the shoreline? Illustrate with a diagram.

B. What is the source of sand making beaches?

C. What happens to the beaches if the supply of sand is cut off?

6. A very large dam is built across a river a few miles from the Pacific Coast. Within a few years after the reservoir, the sandy beaches for many miles along the coast had changed to a rocky shoreline. Discuss why the coastline became rocky after the closure of the dam.

7. Draw a diagram that explains why a lake behind a dam fills in with sediment. Use terms such as velocity, capacity, load, erosion, and deposition.

8. Explain briefly the difference between porosity and permeability in connection with ground water in rocks. Your answer should include at least one example of each of (1) a porous but non-permeable rock, and (2) a rock that is both porous and permeable. What kind would be the good aquifer?

9. Historically in Tucson landfills for waste were located near the rivers, especially the Santa Cruz where land was cheap and the dump was close to major roads and the city. Discuss why this location may not be a good idea. Use a diagram to illustrate your answer.

10. Characterize one type of active crustal plate boundary. For full credit your answer must include the following:

11. Discuss three lines of evidence supporting the concept of subduction. Be sure you clearly indicate how the evidence supports subduction!

12. Discuss three independent lines of evidence for the process of seafloor spreading. Be sure you indicate how each line of evidence supports the idea of seafloor spreading. Use diagrams to illustrate your answer.