Chapter7
16. Normal, reverse, and thrust are all examples of _________ faults.
dip-slip
31. The balance between the weight of a mountain range and the buoyancy provided by the underlying mantle is termed
isostasy.
9. How does the rate at which a body of rock is deformed affect its behavior?
A rock deformed quickly is likely to exhibit brittle behavior.
18. A fold shaped like an elongated arch is a(n)
anticline.
The formation of joints in a rock in response to tension is an example of
brittle deformation.
32. Mountain ranges formed along subduction zones are formed, in part, by ___________ in the crust.
compression
20. Folds are most often associated with _________ stress.
compressional
36. The formation of the Basin and Range Province, a fault-blocked mountain range in Utah, Nevada, and Arizona, is associated with which of the following processes?
continental rifting
41. The outer portion of a craton, where deformed rocks are covered by sediments, is termed the
cratonic platform.
42. Regions of continents that have NOT been subjected to mountain-building events during the past 1 billion years are termed
cratons.
43. Metamorphic rocks found in cratons are exposed during orogenesis by
erosion.
27. The distinction between joints and faults is that
faults are fractures along which displacement has occurred; displacement does not occur along joints.
22. Regularly spaced joints in an outcrop may indicate that an area
has experienced compressional stress.
12. Under which of the following conditions would a body of rock be more likely to exhibit plastic behavior?
high temperature
14. Under which condition would a body of rock be most likely to exhibit brittle behavior?
low temperature
Which of the following is a change in the shape of a rock induced by stress?
Strain
15. How is stress different from strain?
Strain is the change in shape of a rock as a result of applied stress.
38. The Himalayan mountain range was formed at which tectonic setting?
a convergent plate boundary
21. Tectonic foliation is most likely to occur as a result of
metamorphism.
24. On a geologic map, if the contacts between sedimentary rock units form a series of parallel lines, with the youngest unit in the center, the underlying structure is a
non-plunging syncline.
45. What do strike and dip describe?
orientation of planar features
29. An episode of mountain building is termed a(n)
orogeny.
39. As the mountains in a mountain range are slowly eroded, the crustal root
rises out of the mantle.
48. Erosional processes work to remove material from mountains; thus, over time the topography will become less
rugged.
40. Regions where Precambrian metamorphic rocks are exposed at the surface are termed
shields.
8. A body of rock affected by compression will likely undergo
shortening
Force-per-unit area is termed
stress.
10. A body of rock affected by tension will likely undergo
stretching.
17. Right-lateral and left-lateral are both examples of _________ faults.
strike-slip
Which of the following occurs when rocks are pulled apart?
tension
19. Normal faults are generally the result of _________ stress.
tensional
6. What kind of stress results in the lengthening of rock?
tensional
49. Mount Marshak towers above the landscape at 5.3 km tall. The rate of uplift at Mount Marshak is 1.3 mm/yr and the rate of erosion is 1.5 mm/yr. How tall will Mount Marshak be after a million years, assuming everything remains constant?
5.1 km
30. Continental crust is typically 35 km thick but may be up to __________ thick under mountain ranges.
70 km
37. During the formation of Pangea, Africa collided with North America and created the Appalachian Mountains. Which of the following mountain ranges is a modern analogue to the ancient Appalachian Mountains?
Italian Alps
34. Which of these properly illustrates the principle of isostasy?
Mountains stand high because they are gravitationally balanced by their deep crustal roots.
50. What can be said about a mountain range that is being uplifted at 2 cm/yr but is not growing any taller?
The rate of erosion is the same as the rate of uplift.
Which of the following occurs when rocks bend, break, or flow during mountain building?
deformation
7 Which of these is NOT one of the components of deformation?
dissolution
33. Normal faulting is most often associated with mountain building along ___________ boundaries, whereas reverse faulting is generally observed at ___________ boundaries.
divergent; convergent
28. Which of the following is the process whereby rocks from depth are exposed at the surface during mountain building?
uplift
11. Which type of situation would be more likely to produce folds?
warm, ductile crust under compression
35. Mountains forming would be most likely found at the
western South American plate boundary.
