Physical Geology - Chapter 5 Test Bank

54. At what temperature does organic matter begin to convert to oil and gas? A) 90°C B) 50°C C) 190°C D) 150°C

A) 90°C

67. Today reefs constructed mostly by corals. Which organisms made reefs before corals? A) forams B) rudists C) oysters D) armoured fish

B) rudists

18. Which of the following processes occurs during lithification? A) recrystallization of unstable minerals B) compaction C) cementation D) All of these may occur during lithification.

D) All of these may occur during lithification.

14. Which of the following is not a sedimentary structure? A) bioturbation B) cross-bedding C) vesicles D) ripples

C) vesicles

23. Which of the following is an example of a clastic sedimentary rock? A) chert B) dolostone C) evaporite D) shale

D) shale

21. Which of the following statements is true? A) Cementation and compaction both decrease porosity. B) Cementation increases porosity, whereas compaction decreases porosity. C) Cementation decreases porosity, whereas compaction increases porosity. D) Cementation and compaction both increase porosity.

A) Cementation and compaction both decrease porosity.

6. Which of the following statements about transportation of sediment is false? A) Smaller particles settle faster than larger particles. B) As a current slows, the largest particles start to settle. C) Faster currents carry larger particles than slower currents. D) Rivers and ocean currents move much more material than do air currents.

A) Smaller particles settle faster than larger particles.

29. Which of the following types of sandstones is most likely to form by the rapid mechanical weathering of a granite? A) arkose B) graywacke C) quartz arenite D) shale

A) arkose

16. In what type of environment did the ripples depicted below most likely form? A) beach (waves) B) alluvial (stream) C) desert (wind) D) delta (river plus tides)

A) beach (waves)

34. What is the most abundant nonclastic sediment? A) carbonate B) chert C) coal D) halite

A) carbonate

32. The most abundant chemical/biochemical sedimentary rocks are A) carbonates. B) cherts. C) sandstones. D) shales.

A) carbonates.

49. The type of weathering whereby rocks may be dissolved is called A) chemical weathering. B) mechanical weathering. C) physical weathering. D) diagenetic weathering.

A) chemical weathering.

42. Which of the following sedimentary rocks is composed of biochemically precipitated silica? A) chert B) evaporite C) limestone D) quartz arenite

A) chert

22. Which of the following lists is written in order of decreasing particle size? A) conglomerate, sandstone, siltstone B) sandstone, siltstone, conglomerate C) sandstone, conglomerate, siltstone D) siltstone, sandstone, conglomerate

A) conglomerate, sandstone, siltstone

28. In which of the following sedimentary rocks would it be easiest to determine the type of rocks from which the sediment was derived? A) conglomerates B) sandstones C) shales D) siltstones

A) conglomerates

13. In which of the following environments are siliceous sediments deposited? A) deep-sea B) reef C) evaporite D) swamp

A) deep-sea

2. Which of the following terms describes the alteration of sediments to sedimentary rocks after deposition? A) diagenesis B) crystallization C) precipitation D) metamorphism

A) diagenesis

51. The three main types of sediment are A) siliciclastic, biological, chemical. B) bioclastic, chemical, granitic. C) clastic, fossiliferous, bioclastic. D) siliciclastic, erosional, ionic.

A) siliciclastic, biological, chemical.

17. What is the approximate temperature of sediment that is buried to a depth of 4 km? A) 0°C B) 120°C C) 200°C D) 250°C

B) 120°C

45. Coral reefs are generally limited to waters approximately ________ deep or less. A) 5 m B) 20 m C) 100 m D) 20 km

B) 20 m

35. The Bahamas are an example of a(n) A) alluvial environment. B) carbonate platform. C) deltaic deposit. D) rift valley.

B) carbonate platform.

3. What type of sediments are accumulations of solid fragments produced by weathering? A) biochemical sediments B) clastic sediments C) chemical sediments D) all of the above

B) clastic sediments

37. Which of the following minerals does not precipitate directly from seawater? A) calcite B) dolomite C) gypsum D) halite

B) dolomite

44. Which of the following processes is not an important cause of subsidence during the development of a sedimentary basin? A) cooling and contraction of the crust B) erosion of sediments C) deposition of sediments D) tectonic downfaulting

B) erosion of sediments

68. A sedimentary environment contains sand, mud, and gravel and shows little biological activity. Which of the following environments fits this description best? A) desert B) glacial C) lake D) continental slope

B) glacial

31. Which of the following kinds of sandstone is the most poorly sorted? A) arkose B) greywacke C) lithic sandstone D) quartz arenite

B) greywacke

38. The conversion of limestone to dolostone involves the replacement of calcium ions with A) carbonate ions. B) magnesium ions. C) silica ions. D) sodium ions.

B) magnesium ions.

36. Where do atolls form? A) on beaches along active continental margins B) on subsiding volcanic islands C) on tidal flats in humid environments D) on wave-dominated deltas

B) on subsiding volcanic islands

8. The salinity of the ocean A) increases by approximately 1% each year. B) remains approximately constant. C) decreases by approximately 1% each year. D) fluctuates by up to 10% depending on the annual rainfall.

B) remains approximately constant.

46. Which of the following types of sedimentary basins is most likely to develop where two plates pull apart? A) flexural basins B) rift basins C) thermal sag basins D) All of the above are equally likely to develop.

B) rift basins

26. A clastic sedimentary rock composed of medium-grained (1-mm diameter) particles is called a A) conglomerate. B) sandstone. C) shale. D) siltstone.

B) sandstone.

64. Sedimentary particles that are abraded will become A) smaller and more angular. B) smaller and more rounded. C) larger and heavier. D) larger and more angular.

B) smaller and more rounded.

55. Coal is produced from the diagenesis of A) foraminifera. B) swamp vegetation. C) dinosaur bones. D) algae.

B) swamp vegetation.

76. Research on marine evaporates indicates that bulk seawater chemistry has not changed much over approximately the last _______ years? A) 2 million B) 100,000 C) 2 billion D) 4.6 billion

C) 2 billion

5. How fast are moderate-strength river currents that carry and deposit sand? A) 2 to 5 cm/s B) 5 to 20 cm/s C) 20 to 50 cm/s D) 50 to 200 cm/s

C) 20 to 50 cm/s

47. Sedimentary processes take place A) within Earth's interior. B) within Earth's atmosphere. C) at or near Earth's surface. D) within Earth's interior or atmosphere, or near Earth's surface.

C) at or near Earth's surface.

15. What is the term for the process by which organisms burrow through muds and disrupt the sedimentary bedding? A) biochemical precipitation B) cementation C) bioturbation D) cross-bedding

C) bioturbation

62. The major environments for sedimentary deposition are often grouped into A) land and sea. B) terrestrial and marine. C) continental, shoreline, and marine. D) continental, transitional, and marine.

C) continental, shoreline, and marine.

11. In which of the following environments would gravel least likely be deposited? A) alluvial B) beach C) deep-sea D) glacial

C) deep-sea

63. Which of the following is not a clastic sedimentary environment? A) alluvial B) beach C) delta D) evaporate

C) delta

9. Which of the following environments is an example of a shoreline environment? A) alluvial B) continental shelf C) delta D) organic reef

C) delta

12. Which of the following sedimentary environments is dominated by river currents and waves? A) alluvial B) deep-sea C) deltaic D) desert

C) deltaic

73. Which of the following sedimentary rocks' formation does not involve a primary sediment? A) mudstone B) conglomerate C) dolostone D) sandstone

C) dolostone

58. A clastic sedimentary rock contains pieces of coarse-grained quartz. What rock is most likely in the source? A) rhyolite B) andesite C) granite D) gabbro

C) granite

41. Which of the following minerals precipitates directly from water in evaporite deposits? A) dolomite B) feldspar C) gypsum D) quartz

C) gypsum

40. Which of the following is deposited only by nonbiological, chemical precipitation? A) chert B) coal C) halite D) limestone

C) halite

30. What type of sandstone contains abundant rock fragments? A) arkose B) graywacke C) lithic sandstone D) quartz arenite

C) lithic sandstone

72. Which of the following sediment sequences shows increasing grain size (left to right)? A) sand, silt, clay B) silt, sand, mud C) mud, sand, pebble D) gravel, sand, silt

C) mud, sand, pebble

25. Which of the following fine-grained sedimentary rocks is clastic and displays blocky fracture and little or no bedding? A) chert B) coal C) mudstone D) shale

C) mudstone

1. Which of the following sets of processes is written in order of increasing temperature? A) sedimentation, metamorphism, diagenesis B) diagenesis, sedimentation, metamorphism C) sedimentation, diagenesis, metamorphism D) metamorphism, diagenesis, sedimentation

C) sedimentation, diagenesis, metamorphism

52. Sedimentary basins are formed by a process called A) diagenesis. B) subduction. C) subsidence. D) lithification

C) subsidence.

56. If coins represent sediment grains, then which of the following collections of coins would be best sorted? A) 5 pennies and 5 quarters B) 5 pennies, 5 dimes, and 5 quarters C) 8 pennies and 2 quarters D) 10 pennies

D) 10 pennies

69. What sort of sedimentary environments are floodplains? A) desert B) glacial C) lake D) alluvial

D) alluvial

50. The study of sedimentary rocks helps geoscientists determine A) ancient ocean environments. B) former plate tectonic events. C) history of climate change. D) ancient ocean environments, former plate tectonic events, and history of climate change.

D) ancient ocean environments, former plate tectonic events, and history of climate change.

57. A clastic sedimentary rock contains pieces of olivine. What rock is most likely in the source? A) granite B) rhyolite C) andesite D) basalt

D) basalt

59. Two common types of cements in sedimentary rocks are A) calcium and chert. B) quartz and chert. C) quartz and silica. D) calcite and quartz.

D) calcite and quartz.

66. As seawater evaporates the following sequence of minerals/compounds forms (in the order of first to last): A) halite, gypsum, carbonates, Mg- and K-chlorides. B) gypsum, carbonates, halite, Mg- and K-chlorides. C) Mg- and K-chlorides, halite, gypsum, carbonates. D) carbonates, gypsum, halite, Mg- and K-chlorides.

D) carbonates, gypsum, halite, Mg- and K-chlorides.

74. Which sedimentary rock is makes up flint? A) sandstone B) limestone C) gypsum D) chert

D) chert

61. Which of the following sedimentary rocks would be classified as biochemical? A) shale B) siltstone C) sandstone D) coal

D) coal

75. Research suggests that bulk seawater chemistry has not changed much over the last 1.8 billion years. This observation is supported by the study of what kind of sedimentary rock? A) sandstone B) limestone C) chert D) evaporites

D) evaporites

53. The type of sedimentary basin that forms as a result of one tectonic plate overriding another, causing the plate to bend downward, is called a A) thermal subsidence basin. B) tectonic basin. C) rift basin. D) flexural basin.

D) flexural basin.

33. Most of the carbonate sediments of the ocean are derived from A) coral. B) crustaceans. C) fish. D) foraminifera.

D) foraminifera.

20. What is the porosity of newly deposited mud? A) less than 5% B) between 5% and 20% C) between 20% and 50% D) greater than 50%

D) greater than 50%

19. Burial of sediments results in A) decreasing pressure and decreasing temperature. B) decreasing pressure and increasing temperature. C) increasing pressure and decreasing temperature. D) increasing pressure and increasing temperature.

D) increasing pressure and increasing temperature.

48. Physical weathering involves the breakdown of rocks at the Earth's surface through A) chemical reactions. B) diagenesis. C) erosion. D) mechanical processes.

D) mechanical processes.

70. Turbidites are sedimentary deposits that are characterized by A) ripple marks. B) cross-bedding. C) graded bedding. D) poor sorting.

D) poor sorting.

39. Which of the following minerals is least likely to occur in a marine evaporite environment? A) borates B) gypsum C) halite D) quartz

D) quartz

4. Which of the following minerals would be most concentrated at a site containing heavily weathered sediments? A) amphibole B) feldspar C) mica D) quartz

D) quartz

65. If a sediment started out with equal proportion of quartz and feldspar, then which of the following sediment compositions will have been transported the furthest? A) quartz/feldspar = 1 B) quartz/feldspar = 1/2 C) quartz/feldspar = 2/1 D) quartz/feldspar = 3/1

D) quartz/feldspar = 3/1

43. Oil and gas are found mainly in A) chert and gypsum. B) quartzite and dolomite. C) mudstone and siltstone. D) sandstone and limestone.

D) sandstone and limestone.

24. Which of the following rocks is composed of clay-sized clastic sediment? A) conglomerate B) dolostone C) sandstone D) shale

D) shale

27. Which of the following sedimentary rock groups are most abundant? A) cherts and evaporites B) sandstones and conglomerates C) limestones and dolostones D) siltstones, mudstones, and shales

D) siltstones, mudstones, and shales

7. The tendency for variations in current velocity to segregate sediments on the basis of particle size is called A) compaction. B) lithification. C) metamorphism. D) sorting.

D) sorting.

71. Which of the following sedimentary structures suggests the presence of a back-and-forth current? A) asymmetric ripple marks B) cross-bedding C) graded bedding D) symmetric ripple marks

D) symmetric ripple marks

60. A sediment composed of roughly equal amounts of quartz and feldspar grains is transported over a long distance. What will the sediment end up looking like? A) well-sorted and rounded grains consisting of mostly of feldspar B) well-sorted and rounded grains consisting mostly of quartz C) well-sorted and rounded grains consisting entirely of felspar D) well-sorted and rounded grains consisting entirely of quartz

D) well-sorted and rounded grains consisting entirely of quartz