Geology 101
Exam #5
Fall 2003

Multiple Choice


1. What was Pangaea?
a. a fern-like plant with large seeds
b. an ocean that existed between Africa and Europe prior to the present day Mediterranean Sea
c. a supercontinent that consisted of South America, Africa, Australia, India and Antarctica
d. an aquatic snaggle-toothed reptile
e. a supercontinent that began to break apart about 200 mya leading to present day continents

2. Which of the following is a passive continental margin?
a. west coast of Europe
b. west coast of South America
c. west coast of the United States
d. east coast of Japan
e. all of the above

3. Which of these is/are associated with a subduction zone?
a. Columbia River flood basalts
b. Mt. Rushmore
c. Sierra Nevada batholith
d. Hawaiian islands
e. volcanic island arcs

4. Prior to plate tectonics being an accepted theory, how did geoscientists and others believe that land animals migrated across vast areas of ocean?
a. they believed that continents were once all connected in a supercontinent
b. most animals swam but some were blown across the ocean by strong winds
c. the animals were blown across the oceans in hot air balloons
d. they believed that a few animals drifted across oceans on logs and other floating objects and then reproduced to produce new viable populations
e. they believe that continents were connected by land bridges

5. What information is key to identifying the locations of lithospheric plate boundaries?
a. location of earthquakes
b. location of granites
c. location of passive margins
d. variations in igneous rock types
e. all of the above

6. What are the three basic types of plate boundaries
a. subduction, reduction, deduction
b. rifts, seams, valleys
c. mid ocean ridges, spreading centers, subduction zones
d. volcanic arcs, transform faults, subduction zones
e. divergent, convergent, transform fault

7. Gondwanaland continents all show evidence of glaciation. Why?
a. the northern continents were all connected and located near the north pole at one time
b. there have been long term climate changes
c. those continents have always been located at very high or very low latitudes
d. during periods of magnetic reversals, the coriolis force means that temperatures are low
e. at one time Gondwanaland was located near the South Pole

8. Which of the following is/are involved in the formation of new crust at mid ocean ridges?
a. hot asthenosphere rises
b. magma reaches the surface
c. pillow basalts may form
d. crust moves away from ridges
e. all of the above

9. If new crust is being created at mid ocean ridges, we might think that means that the Earth is getting larger. But, it isnt. Why doesnt the Earth get larger?
a. transform faults take up some of the slack
b. island arcs are also sites of new crustal formation
c. continents drift apart making more room for the new crust
d. old crust is subducted in subduction zones
e. all of the above

10. Who is credited with formulating the modern idea of seafloor spreading?
a. James T. Wilson
b. Linus Pauling
c. Alfred Wegener
d. Vine and Matthews
e. Harry Hess

11. When geophysicists study the magnetism of the ocean floors, they find marine magnetic anomalies. These anomalies are due to
a. the rotation of the earth is sometimes faster than at other times
b. volcanoes are most common along continental margins
c. continents have drifted around the globe over time
d. the earths magnetic poles have not always been in the same places
e. at various times in Earths history, the north and south magnetic poles have switched

12. When Wegener first proposed the idea of continental drift, many scientists were skeptical because:
a. he could not explain the mechanism or why it was happening
b. he said continental crust plowed through oceanic crust
c. gravity studies suggested the crust was partially melted
d. seismologists showed that the crust could not move
e. both answers (a) and (b) above are correct

13. Where is new lithosphere being formed?
a. mostly at island arcs and subduction zones
b. island arcs and tectonic belts
c. transform zones and tectonic belts
d. subduction zones and tectonic belts
e. mid-ocean rifts primarily

14. At which of these places is subduction occurring?
a. east coast of the U.S.
b. east coast of Africa
c. east coast of S. America
d. west coast of S. America
e. west coast of Europe

15. The outer (tectonic) layer of the Earth, consisting of the crust and outermost mantle, is called the
a. crust
b. mantle
c. outer core
d. asthenosphere
e. lithosphere

16. Why is oceanic lithosphere subducted while continental lithosphere is not?
a. oceanic lithosphere is not moving relative to the mantle
b. continental lithosphere is not moving relative to the mantle
c. subduction does not take place in continental areas
d. oceanic lithosphere is too dense
e. continental lithosphere is too buoyant

17. 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

18. The Hawaiian Islands are located over a
a. subduction zone
b. mid-ocean ridge
c. guyot
d. transform fault
e. hot spot

19. What do the Japanese Islands have in common with the Andes?
a. both are in the Atlantic
b. both formed by continental collision
c. both are back arc basins
d. both are at diverging margins
e. both are associated with subduction zones

20. The Earths crust is old and extremely thick
a. in the center of continents
b. at continental margins
c. at transform faults
d. at subduction zones
e. at mid ocean ridges

21. Which event formed the Rocky Mountains?
a. Alpine Orogeny
b. Sevier Orogeny
c. Taconic Orogeny
d. Grenville Orogeny
e. Laramide Orogeny

22. The Aleutian Islands are
a. along a mid ocean ridge
b. located above hot spots
c. along a divergent boundary
d. no longer volcanically active
e. very young volcanic islands

23. The Hadean Eon
a. includes the most recent 6-7 million years
b. includes most of the Cenozoic and some of the Paleozoic
c. includes all time since the end of the Precambrian
d. includes all the various parts of the Precambrian
e. includes the earliest time in Earth history

24. Which of the following is the youngest North American mountain building event?
a. Alpine Orogeny
b. Himalayan Orogeny
c. Taconic Orogeny
d. Grenville Orogeny
e. Laramide Orogeny

25. Brunhes, Matuyama, Gauss and Gilbert are
a. the creators of plate tectonics
b. the first people to map the ocean floor
c. the name of the first submersibles that went down to the deepest parts of the ocean
d. the name of the first ocean going ships that drilled holes in the ocean floor
e. names of time periods associated with changes in the Earths magnetic field

26. When did the modern day Atlantic Ocean form?
a. about 4.0 bya
b. about 2.7 bya
c. about 600 mya
d. 200-160 mya
e. 55-60 mya

27. The earliest Earth crust formed
a. about 4.0 bya
b. about 2.7 bya
c. about 600 mya
d. 200-160 mya
e. 55-60 mya

28. Geologists determine polar wander paths primarily by
a. looking at fossils
b. correlating rocks across oceans
c. examining the fit of continents
d. looking at the age of the oceanic crust
e. measuring the magnetic field in rocks

29. What is was Glossopteris ?
a. a fern-like plant with large seeds
b. an ocean that existed between Africa and Europe prior to the present day Mediterranean Sea
c. a supercontinent that consisted of South America, Africa, Australia, India and Antarctica
d. an aquatic snaggle-toothed reptile
e. a supercontinent that began to break apart about 200 mya leading to present day continents

30. Crust that has not been affected by orogeny for a very long time is called a
a. craton
b. fault-block mountain
c. anticline
d. exotic terrane
e. mylonite

31. the Basin and Range province
a. is centered on Nevada
b. has many horst and graben structures
c. formed just a few 10s of million years ago
d. formed during crustal extension
e. all of the above

32. The mountains along some continental margins contain accreted terranes. What sorts of margins?
a. transform faults
b. convergent
c. divergent
d. mid ocean ridges
e. suture zones

33. The Canadian Shield contains many old metamorphic and igneous rocks that formed deep in the earth. Why do we see them at the surface today?
a. there used to be mountain ranges there
b. due to uplift and erosion
c. most old basement rocks are igneous and metamorphic
d. these are tough rocks that resist weathering and erosion
e. all of the above

34. The nearest craton to Grand Forks is
a. in California
b. in Canada, just north of the Minnesota border
c. in the Appalachian Mountains
d. in the Grenville belt, located mostly in Ontario but also in parts of New York state
e. right here, we are on one

35. What types of mountains are found in much of Nevada?
a. anticlines
b. synclines
c. fault-block mountains
d. slickensides
e. shields

36. Todays Himalayan Mountains are a product of what sort of collision?
a. ocean-ocean
b. ocean-continent
c. continent-continent
d. dont choose this answer
e. dont choose this answer

37. The average composition of the asthenosphere is
a. granite
b. limestone
c. sandstone
d. basalt
e. peridotite

38. More than 70% of present day coal usage is for what purpose?
a. driving cars and trucks
b. heating buildings
c. making geothermal energy
d. making synfuels
e. generating electricity

39. Placers are formed
a. at mid ocean ridges
b. by hydrothermal solutions
c. at contacts between igneous and sedimentary rock, generally near subduction zones
d. by gravity settling of heavy minerals
e. from the alteration of igneous rocks

40. Most commercial nuclear reactors
a. use plutonium instead of uranium as fuel
b. use thorium-232, cesium-239 or lead-204 as fuel
c. rely on coal to keep temperatures hot enough for fission
d. pollute less than conventional reactors because they consume many of their daughter products
e. use a minor isotope of uranium as the principle energy source

41. Oil traps:
a. can stop upward migration of oil
b. can stop upward migration of gas
c. must include a good reservoir rock
d. must include a good cap rock
e. all of the above are correct

42. Bauxite
a. comes from roasting limestone
b. can be mixed with other ingredients to produce Portland cement
c. can be mixed with other ingredients to produce concrete
d. contains aluminum
e. all of the above

43. Which of the following processes may account for the formation of an ore deposit?
a. circulation of hydrothermal fluids
b. gravity settling associated with a magma
c. gravity settling associated with a river
d. weathering and leaching
e. all of the above

44. Most of the worlds major economic mineral deposits are in
a. shield areas
b. subduction zones
c. the deepest parts of the ocean
d. the shallowest parts of the ocean
e. depositional basins

45. Which of the following are considered nonmetallic mineral resources?
a. garnets
b. aggregate
c. fertilizer
d. sulfur
e. all of the above

46. Which of the following are reasons that the nuclear energy industry is not doing too well?
a. nuclear energy is expensive compared to other energy sources
b. people are concerned about a serious accident
c. we know of no good way to get rid of nuclear waste
d. no one wants a nuclear plant in their backyard
e. all of the above

47. Which of the following is a problem with coal as an energy source?
a. it produces CO₂ when burned
b. mining it can sometimes turn surface areas into scarred wastelands
c. underground coal mining is a very hazardous occupation
d. it often produces sulfur and other pollutants when burned
e. all of the above

48. In the carbon cycle, where can carbon be stored?
a. in underground coal
b. in limestone
c. in the oceans
d. in underground oil
e. all of the above

49. The most significant urban air pollutant in most big cities is
a. sulfur
b. coal
c. ozone
d. CO₂
e. carbon monoxide

50. Since the industrial revolution, the concentration of CO₂ in Earths atmosphere has ______________ and the average Earth temperature has _____________.
a. gone down; gone down
b. gone down; gone up
c. gone up; gone down
d. gone up; gone up
e. all of the above


Short Answer


Note: You may want to refer to the attached sheet (time scale listing geological events) for information.


51. What is geothermal power and how is it used? What is the ultimate origin of the energy that we tap when we use geothermal power? What do we use geothermal power for today? Is geothermal power considered an inexhaustible energy source? Explain why or why not.


52. Compare the mountain building events that created the Andes with those that created the Himalayas. How are they the same? How are they different?


53. Describe the events that led to the formation of the Appalachian Mountains. Be specific about what events happened, when and where.