Geology 101
Exam #5
Spring 2001
Short Answer

1. What factors, other than magnitude, determine whether an earthquake will cause lots of damage or kill many people?
2. Why are the major mountain belts mostly found around the margins of continents?
3. What evidence is there to suggest that the Earth has a metallic core? And, what evidence is there to suggest that the outer part of that core is liquid?
4. How are mid-ocean ridges related to seafloor spreading?
5. What is an outcrop?

Multiple Choice Questions

1. If compressional forces are applied to a layer of rock, it can produce
a. folds or normal faults
b. folds or reverse faults
c. folds but not faults
d. normal faults but not folds
e. reverse faults but not folds

2. If extensional forces are applied to a layer of rock, it can produce
a. folds or normal faults
b. folds or reverse faults
c. folds but not faults
d. normal faults but not folds
e. reverse faults but not folds

3. "...the change in the shape and/or volume of a rock unit caused by forces acting on the rock unit."
a. stress
b. strain
c. compression
d. tension
e. fold

4. The difference between elastic deformation and plastic deformation is that
a. elastic deformation is not reversible
b. plastic deformation is not reversible
c. elastic deformation is brittle
d. plastic deformation never occurs
e. elastic deformation never occurs

5. __________ is the compass direction of a line produced by the intersection of an inclined rock layer or fault, with a horizontal plane.
a. plunge
b. dip
c. strike
d. trend
e. anticline

6. The center of the Black Hills has been uplifted, so the rocks sort of form a dome over the top. This sort of structure is a kind of
a. thrust fault
b. reverse fault
c. normal fault
d. anticline
e. syncline

7. Fault block mountains and horst & graben structures are characterized by __________.
a. thrust faults
b. reverse faults
c. normal faults
d. strike-slip faults
e. detachment faults

8. The San Andreas Fault is a classic example of a ______________.
a. thrust fault
b. reverse fault
c. normal fault
d. strike-slip fault
e. detachment fault

9. When we say an earthquake is "magnitude 7" we are using the
a. bathroom scale
b. Mercalli scale
c. Richter scale
d. Wadati-Benioff scale
e. fish scale

10. Which type of seismic wave moves fastest?
a. P-wave
b. S-wave
c. surface wave
d. ocean wave
e. secondary wave

11. What factor contributed to the extensive damage that occurred in the central portion of Mexico City during the 1985 earthquake?
a. tsunami
b. poverty
c. the ground was soft sediment
d. the ground was mostly granite
e. the ground underwent liquefaction

12. What is a tsunami?
a. an especially strong earthquake
b. a landslide triggered by an earthquake
c. a tidal wave triggered by an earthquake
d. a strong but unfelt earthquake
e. a not very strong earthquake that is easily felt

13. Around 1960, there was lots of money available so seismologists could set up seismographs. Why?
a. the economy was booming
b. John F. Kennedy was President
c. the National Science Foundation was created
d. Vine and Matthews confirmed seafloor spreading
e. the cold war

14. Many earthquakes take place around the margin of the Pacific Ocean because
a. the rocks are brittle
b. subduction takes place there
c. ocean water is interacting with continents
d. the Pacific Ocean is surrounded by the San Andreas Fault
e. that is the only place where continental plates are diverging rapidly

15. The boundary between the crust and the mantle is the
a. P wave shadow zone
b. inner core
c. outer core
d. Benioff zone
e. Moho

16. How thick is the crust of the earth?
a. 0-2 km
b. 2-4 km
c. 0-10 km
d. 2-10 km
e. 0-70 km

17. The asthenosphere is part of the Earth's
a. crust
b. mantle
c. outer core
d. inner core
e. lithosphere

18. The outer layer of the Earth, consisting of the crust and outermost mantle, is called the
a. crust
b. mantle
c. outer core
d. inner core
e. lithosphere

19. Which type of seismic wave does not travel through liquid?
a. P-wave
b. S-wave
c. surface wave
d. ocean wave
e. primary wave

20. Geologists and physicists believe the core of the Earth is mostly
a. quartz
b. nickel
c. carbon
d. magnesium
e. iron

21. What ocean floor features are associated with the oldest rocks?
a. subduction zones
b. transform faults
c. reverse faults
d. mid-ocean ridges
e. guyots

22. Where is new lithosphere being formed?
a. subduction zones
b. transform faults
c. reverse faults
d. mid-ocean ridges
e. guyots

23. The ocean floor contains magnetic stripes caused by ________________.
a. volcanoes
b. earthquakes
c. subduction
d. the coincidence of transform faults and arc volcanism
e. reversal of the Earth's magnetic field

24. Pangaea is
a. a type of fold-belt mountain
b. a type of igneous rock associated with transform faults
c. the name of a supercontinent that once existed
d. the theory that explains why earthquakes and volcanoes occur around the Pacific Ocean
e. all of the above

25. What type of plate boundary is most directly associated with mountain building?
a. transform fault
b. divergent margin
c. convergent margin
d. spreading center
e. basin and range

26. Which of the following is a passive continental margin?
a. the west coast of South America
b. the Aleutian Islands
c. Hawaii
d. the Rocky Mountains
e. the east coast of the United States

27. The Earth's crust is extremely thin or nonexistent
a. in the center of old continents
b. at active continental margins
c. at transform faults
d. at subduction zones
e. at mid ocean ridges

28. The type of stress that normally occurs at converging plate boundaries is:
a. compression
b. tension
c. strain
d. shearing
e. any of the above

29. A normal fault occurs as a result of:
a. tensional stress, and the hanging wall moves down relative to the footwall.
b. tensional stress, and the hanging wall moves up relative to the footwall.
c. compressional stress, and the hanging wall moves down relative to the footwall.
d. compressional stress, and the hanging wall moves up relative to the footwall.
e. shear stress, and the hanging wall moves down relative to the footwall

30. Earthquakes measuring 5 and 7 on the Richter scale differ in wave amplitude by:
a. 2 times
b. 10 times
c. 100 times
d. 7/5 = 1.4 times
e. 5/7 = 0.7 times