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