GEOS 301 Exam 2 - Chap 6 Test Bank
80. At temperatures of approximately 600˚C and pressure of approximately 5 kbar, the minerals muscovite and quartz react with each other and produce orthoclase feldspar, sillimanite, and water. Which mineral is the source of the water? A) orthoclase feldspar B) muscovite C) sillimanite D) quartz
muscovite
61. Metamorphism happens when rocks are subjected to A) new temperatures and pressures. B) fluids. C) whole-scale melting. D) atmospheric gases.
new temperatures and pressures (also hydrothermal FLUIDS. this question is dumb)
60. Which of the following metamorphic rocks is most likely to contain visible fossils? A) gneiss B) hornfels C) marble D) quartzite
not marble probably gneiss because it's the most coarse
85. Differences in the P-T paths experienced by metamorphic rocks in ocean-continent collision zones versus continent-continent collision zones are mainly due to differences in A) pressure. B) rock composition. C) temperature gradients. D) plate subduction rates.
plate subduction rates (but temperature gradients matter too)
82. Metamorphic geologists often refer to the "P-T path" of a particular rock. What does the "P-T" stand for? A) plate-tectonic B) phorphyroblastic-texture C) pressure-temperature D) part-time
pressure-temperature
25. Which of the following metamorphic rocks is incorrectly paired with its parent rock? A) greenstone - basalt B) quartzite - granite C) marble - limestone D) schist - shale
quartzite - granite
12. What type of metamorphism is caused by high temperature and high pressure imposed over a large volume of crust? A) burial B) contact C) regional D) shock
regional
40. Under what conditions does zeolite-facies metamorphism occur? A) relatively low pressure and low temperature B) relatively low pressure and high temperature C) relatively high pressure and low temperature D) relatively high pressure and high temperature
relatively low pressure and low temperature
56. The flow of metamorphic rocks back to Earth's surface is controlled by tectonics and A) erosion. B) hydrothermal circulation. C) magmatism. D) retrograde metamorphism.
retrograde metamorphism
62. Metasomatism does not involve a change in A) bulk rock chemistry. B) mineral composition. C) fluid composition. D) rock texture.
rock texture
49. The parent rock of quartzite is A) granite. B) limestone. C) shale. D) sandstone.
sandstone
26. Which of the following metamorphic rocks is always foliated? A) hornfels B) marbles C) quartzites D) schists
schists
11. What is the primary source of the carbon dioxide in metamorphic fluids? A) atmospheric carbon B) carbon dioxide released from Earth's core C) sedimentary carbonates D) weathered cement and other man-made materials
sedimentary carbonates
38. What is the most likely parent rock of a metamorphic rock containing muscovite, biotite, garnet, and quartz? A) basalt B) limestone C) sandstone D) shale
shale
50. The parent rock(s) of granofels is(are) A) shale. B) impure sandstone. C) granite. D) shale, impure sandstone, and granite.
shale, impure sandstone, and granite
69. In a thickened lithosphere you expect to see A) thinner crust. B) shallower geothermal gradients. C) steeper geothermal gradients. D) constant temperature increase with depth
shallower geothermal gradients
47. What kind of metamorphism would you expect to see in the rocks at a meteorite impact site? A) shock B) burial C) regional D) contact
shock
63. What kind of metamorphism would you expect to be pervasive on the lunar surface? A) regional metamorphism B) burial metamorphism C) contact metamorphism D) shock metamorphism
shock metamorphism
18. What type of metamorphic rock was once used to make blackboards because of its ability to split easily into thin sheets along smooth, parallel surfaces? A) hornfels B) quartzite C) schist D) slate
slate
23. Which of the following sequences describes the metamorphic changes in a shale with increasing metamorphic grade? A) schist, gneiss, slate B) slate, schist, gneiss C) gneiss, slate, schist D) gneiss, schist, slate
slate, schist, gneiss
2. Which of the following tectonic settings will be coolest at 30 km depth? A) regions of continental extension B) stable continental lithosphere C) volcanic arcs D) The temperature in all three tectonic settings above will be the same at 30 km depth
stable continental lithosphere
71. In which of the following tectonic settings is the depth to the 1300˚C isotherm greatest? A) volcanic mountain belt B) subduction zone C) zone of plate extension D) stable continental lithosphere
stable continental lithosphere
3. Which of the following minerals is diagnostic of metamorphism? A) calcite B) feldspar C) staurolite D) quartz
staurolite
58. Which mineral is commonly found as a porphyroblast? A) quartz B) biotite C) mica D) staurolite
staurolite
43. Mélanges and blueschists are characteristic of which tectonic setting? A) continent collisions B) subduction zones C) mid-ocean ridges D) transform faults
subduction zones
66. Geologists have recently linked rapid rates of uplift and exhumantion to A) tectonic setting. B) rock type. C) climate. D) isograds.
tectonic settings
75. During metamorphism, the process called metasomatism does not change the ______ of the affected rock. A) chemical composition B) mineral chemistry C) mineral content D) texture
texture
5. A geothermometer is A) a device that measures current rock temperatures. B) a device that measures temperature when lowered into deep drill holes. C) a mineral assemblage that reveals the maximum temperature attained by a rock. D) the range of temperatures encountered by a rock in its geologic history
the range of temperatures encountered by a rock in its geologic history
70. Which of the following factors remains constant and does not vary depending on tectonic setting? A) the geothermal gradient B) the thickness of the lithosphere C) the rate of pressure increase with depth D) the depth to the 1300˚C isotherm
the rate of pressure increase with depth
20. Which of the following is not used to classify foliated rocks? A) the metamorphic grade B) the size of the crystals C) the nature of the foliation D) the texture of the parent rock
the texture of the parent rock
35. What is a porphyroblast? A) a common type of copper ore deposit B) an igneous rock with two distinct crystal sizes C) a relatively large metamorphic mineral D) a strongly foliated metamorphic rock
this is a dumb question with no right answer (maybe B but it's not igneous)
48. Eclogite rocks form during ___________ metamorphism. A) high-pressure B) ultra-high-pressure C) burial D) seafloor
ultra-high-pressure
78. One would expect shock metamorphism to be less common on Earth than on the Moon. This is because the moon has A) a smaller diameter. B) lower gravity. C) softer crust. D) virtually no atmosphere.
virtually no atmosphere
74. During metamorphism, hydrothermal fluids can remove all _____ from an affected rock. A) solids B) minerals C) water-soluble chemical elements D) chemical elements
water-soluble chemical elements
67. Which metamorphic facies would be highly unlikely to occur in a subduction zone? A) zeolite B) blueschist C) eclogite D) granulite
zeolite
6. What is the average rate at which temperature increases with depth in Earth's crust? A) 10°C/km B) 30°C/km C) 100°C/km D) 300°C/km
30 C/km
4. Approximately what is the pressure on a rock at 15 km depth in Earth's crust? (Note: 1 bar is approximately 1 atmosphere and 1000 bars equals 1 kbar.) A) 4 bars B) 40 bars C) 400 bars D) 4 kbars
4 kbars
14. At what depth does low-grade metamorphism begin? A) 1 to 2 km B) 6 to 10 km C) 20 to 50 km D) 100 to 200 km
6 to 10 km
73. Directed pressure is also sometimes called A) confining pressure. B) differential stress. C) differential pressure. D) confining stress.
differential stress
15. Where does seafloor metamorphism take place? A) continent collision zones B) subduction zones C) divergent plate boundaries D) transform plate boundaries
divergent plate boundaries (mid ocean ridges)
30. Granoblastic metamorphic rocks generally contain minerals that are _______ in shape. A) linear B) platy C) equant D) bladed
equant
55. The process whereby metamorphic rocks rise to Earth's surface is called A) exhumation. B) orogeny. C) subduction. D) progradation.
exhumation
72. During metamorphism pressure will ____ the rocks in the direction a force is applied and ____ in the direction perpendicular to that same force. A) elongate; flatten B) elongate; elongate C) flatten; elongate D) flatten; flatten
flatten; elongate
17. The parallel alignment of mica in a metamorphic rock is an example of A) bedding. B) foliation. C) metasomatism. D) porphyroblasts.
foliation
34. Which metamorphic mineral commonly forms porphyroblasts? A) amphibole B) calcite C) chlorite D) garnet
garnet
41. Which mineral is commonly used to determine a metamorphic P-T path? A) calcite B) garnet C) muscovite D) quartz
garnet
46. Metamorphic mineral assemblages that can be used as pressure gauges are referred to as A) kilobarometers. B) geothermometers. C) geobarometers. D) kilothermometers.
geobarometers
79. Which of the following metamorphic rocks can be either foliated or phorphyroblatstic, but not granoblastic? A) hornfels B) marble C) granulite D) gneis
gneis
19. Which of the following rocks represents the highest metamorphic grade? A) gneiss B) phyllite C) schist D) slate
gneiss
24. Light-colored rocks with coarse bands of segregated light and dark minerals are called A) gneisses. B) quartzites. C) schists. D) slates.
gneisses
39. Which of the following metamorphic facies represents the highest temperature? A) amphibolite B) blueschist C) granulite D) greenschist
granulite
57. What type of metamorphic rock is granofels? A) a granulite B) a schist C) a gneiss D) a marble
granulite
36. Which of the following rocks represents the highest grade of metamorphosed mafic volcanic rocks? A) amphibolite B) blueschist C) greenschist D) granulite
greenschist
37. What metamorphic facies occurs at temperatures of 400°C and pressures of 6 kilobars? A) granulite B) greenschist C) hornfels D) zeolite
greenschist
28. Which of the following metamorphic rocks forms from mafic volcanic rocks? A) greenstone B) marble C) quartzite D) all of the above
greenstone
84. For any given depth along the P-T path of a metamorphic rock the retrograde path is always at a A) lower pressure. B) higher pressure. C) lower temperature. D) higher temperature.
higher pressure.
27. Which of the following rocks has a granular texture? A) gneiss B) hornfels C) schist D) slate
hornfels
29. A nonfoliated contact metamorphic rock is called a A) gneiss. B) hornfels. C) phyllite. D) schist.
hornfels
8. During metamorphism, changes in the bulk composition of a rock occur primarily as a result of A) increases in pressure. B) reaction with hydrothermal fluids. C) increases in temperature. D) decreases in temperature
increases in temperature
52. Different pressure-temperature zones within a belt of regionally metamorphosed rock are defined by the presence of A) porphyroblasts. B) index minerals. C) migmatite. D) sillimanite.
index minerals.
51. A metamorphic rock that is described as porphyroblastic has A) original igneous rock textures. B) abundant equant minerals. C) large crystals in a fine-grained matrix. D) no preferred alignment of minerals.
large crystals in a fine-grained matrix.
64. Under what P and T conditions does zeolite-facies metamorphism occur? A) less than 5 kbars and 200°C B) 5 to 10 kbars and 200 to 400°C C) less than 5 kbars and greater than 400°C D) greater than 5 kbars and less than 400°C
less than 5 kbars and 200 C
1. Marble is a metamorphic rock that forms from A) granite. B) limestone. C) sandstone. D) shale
limestone
68. During metamorphism a rock will not A) loose its solid form. B) change shape. C) change its texture. D) experience metasomatism.
loose its solid form
83. For any given depth along the P-T path of a metamorphic rock the prograde path is always at a A) lower pressure. B) higher pressure. C) lower temperature. D) higher temperature.
lower pressure
31. Which of the following metamorphic rocks cannot form from a shale? A) hornfels B) marble C) schist D) slate
marble
32. What type of metamorphic rock has undergone partial melting? A) hornfels B) migmatite C) schist D) slate
migmatite
33. Which of the following rocks can be considered gradational between an igneous and a metamorphic rock? A) amphibolite B) gneiss C) migmatite D) zeolite
migmatite
45. What metamorphic rock could also be considered a transitional rock between igneous and metamorphic? A) schist B) hornfels C) gneiss D) migmatite
migmatite
16. What is the relationship between metamorphic foliation and sedimentary bedding? A) Sedimentary bedding is generally perpendicular to metamorphic foliation. B) Sedimentary bedding is generally at a 45° angle to metamorphic foliation. C) Sedimentary bedding is generally parallel to metamorphic foliation. D) There is no general angular relationship between sedimentary bedding and metamorphic foliation.
There is no general angular relationship between sedimentary bedding and metamorphic foliation
54. What kind of metamorphism(s) would you expect to find at a convergent plate margin? A) regional B) high-pressure C) contact D) all of the above
all of the above
7. Which of the following processes will cause metamorphism? A) an increase in pressure B) interaction with hydrothermal fluids C) an increase in temperature D) all of the above
all of the above
59. Metamorphic rocks may form from A) igneous rocks. B) sedimentary rocks. C) other metamorphic rocks. D) any of the major rock types.
any of the major rock types
53. Epidote is a common metamorphic mineral found in metamorphosed A) shale. B) limestone. C) basalt. D) sandstone.
basalt
44. Which metamorphic rock forms in the forearc of a subduction zone? A) amphibolite B) blueschist C) hornfels D) granulite
blueschist
42. The prograde part of a metamorphic P-T path occurs during A) burial and cooling. B) exhumation and cooling. C) burial and heating. D) exhumation and heating.
burial and heating
76. Carbon dioxide is one of the fluids consumed during metasomatism. What is the likely source of this fluid? A) silicate minerals B) the atmosphere C) the core D) carbonate rocks
carbonate rocks (limestones and dolostones)
77. Oil companies rarely drill deeper than the _____ isotherm. A) 100˚C B) 150˚C C) 200˚C D) 250˚C
150 C
22. Which of the following statements about the metamorphism of a shale is false? A) With increasing metamorphism, clay minerals break down to form micas. B) With increasing metamorphism, the grain size of the rock gets smaller. C) With increasing metamorphism, foliation develops. D) With increasing metamorphism, the amount of water in the rock decreases.
With increasing metamorphism, the grain size of the rock gets smaller
10. What is metasomatism? A) a change in the bulk composition of a rock during metamorphism B) metamorphism caused by nearby magmatic intrusions C) metamorphism caused by tectonic movements along faults D) the parallel alignment of minerals in a metamorphic rock
a change in the bulk composition of a rock during metamorphism
65. One might expect shock metamorphism to be more common on the lunar than terrestrial surface because the Moon has __________ than Earth. A) a thicker atmosphere B) a denser atmosphere C) a less dense atmosphere D) higher atmospheric pressures
a less dense atmosphere (so more things make it through the atmosphere and hit the surface)
9. Which of the following is a general pressure in all directions, such as the pressure that the atmosphere exerts? A) confining pressure B) pore pressure C) directional pressure D) stress pressure
confining pressure
13. What type of metamorphism is caused by igneous intrusions? A) burial metamorphism B) regional metamorphism C) contact metamorphism D) shock metamorphism
contact
81. In which plate tectonic setting is evidence of shock metamorphism most likely to be preserved? A) convergent plate boundaries B) transform faults C) divergent plate boundaries D) continental interiors
continental interiors
21. Which of the following tectonic settings may be characterized by regional, high-pressure, and ultra-high-pressure metamorphism? A) convergent plate boundaries B) plate interiors C) divergent plate boundaries D) transform plate boundaries
convergent plate boundaries