Ch.15 Weathering, Soil, And Unstable Slopes Full Test Bank

Exploring Geology, 5e (Reynolds)

Chapter 15 Weathering, Soil, and Unstable Slopes

1) What events caused so much damage along the north coast of Venezuela in 1999?

A) A landslide shook loose a large piece of the mountains that caused the water in the reservoir to flood local towns.

B) Torrential rains caused debris flows and flash floods that raced through cities.

C) The slow movement of slopes downhill broke apart houses but did not kill any people.

D) Overgrazing caused a loss of grass cover and resulted in severe soil erosion.

2) What should have warned the people of coastal Venezuela that they were in a hazardous zone?

A) The cities were built upon alluvial fans.

B) The houses had been built on debris flow deposits.

C) The areas above the city had steep unstable slopes.

D) All of these choices are correct.

3) The joints in the photograph mimic topography, indicating that they formed

A) while the granite was still molten.

B) while the rocks were still buried at great depth.

C) when the weight of overlying rocks was unloaded, allowing expansion along the joints.

D) along a subduction zone.

4) What is the dominant type of weathering shown in this photograph?

A) dissolution

B) chemical weathering

C) debris flow

D) hydrolysis

E) physical weathering

5) Which of the following does NOT physically loosen rocks on the surface?

A) water contracting as it freezes

B) crystals of salt and other minerals that exert an outward force on fractures

C) roots that pry apart fractures as the root grows in size

D) joints that form when rock pressures are released

E) rodents and other burrowing organisms

6) What happens to the surface area of exposed rock if a rock is fractured?

A) There are more pieces, but the surface area does not change.

B) The surface area does not change because the volume does not change.

C) The surface area increases as the rock is fractured.

D) The surface area decreases as the rock is fractured.

7) What is the main reason why the oceans are salty?

A) The early oceans were salty because comets are dirty snowballs.

B) Salt deposits that formed early in Earth's history become dissolved by modern oceans.

C) Weathering of rocks releases chemical elements that make the oceans salty.

D) Blowing salt crystals become incorporated into clouds and fall with the rainfall.

8) Joints in the landscape

A) mostly form at depth and are uplifted to the surface.

B) can detach thin slices of rock parallel to the land surface.

C) are less resistant to weathering when they are highly jointed areas than the less-jointed ones.

D) All of these choices are correct.

9) Some rocks and minerals are not stable at the surface because they

A) are exposed to water.

B) formed in high-temperature environments.

C) formed in high-pressure environments.

D) are exposed to oxygen.

E) All of these choices are correct.

10) What is a common rock that can be dissolved by water and weak acids?

A) Quartzite

B) Quartz-rich sandstone

C) Limestone

D) All of these choices are correct.

11) What happens when rocks oxidize near Earth's surface?

A) Minerals in the rock release oxygen that can break down adjacent rocks.

B) Oxygen combines with water to create weak acids that weather rocks.

C) Minerals, especially those with iron, combine with oxygen.

D) Oxygen combines with silica to make quartz.

12) What concepts can be explained using this diagram?

A) the movement of water between the oceans and the land

B) how precipitation ends up in rivers or groundwater

C) how weathering causes the seas to become saltier

D) All of these choices are correct.

13) What is the main type of weathering illustrated by this weathered limestone?

A) physical weathering

B) dissolution

C) oxidation

D) exfoliation

14) The layer of quartzite in this photograph would mostly weather by

A) dissolution.

B) hydrolysis.

C) physical weathering.

D) spontaneous combustion.

15) Where does the quartz in granite typically end up?

A) As small clay minerals that are deposited in lakes and the sea.

B) Quartz does not weather and so it keeps the granite from weathering.

C) It ends up as sand in rivers, dunes, and beaches.

D) It is converted into feldspar and weathers into clays.

16) Which of the following factors control how minerals weather?

A) whether the mineral has ionic or covalent bonds

B) what type of mineral is present

C) the temperature at which the original minerals formed

D) whether a mineral typically crystallizes early or late in Bowen's Reaction Series

E) All of these choices are correct.

17) Which of the following is valid for how rocks weather?

A) quartz is very soluble during weathering at low temperatures

B) limestone weathers rapidly in wet climates but can form cliffs in dry ones

C) as a granite weathers, quartz rapidly decomposes into clay minerals

D) most minerals in granite weather at nearly the same rate and so granite has smooth surfaces

18) How does the character of a rock influence weathering?

A) Fractures and other discontinuities block the entry of water into a rock and so make the rock more resistant to weathering.

B) Minerals that are soluble can be dissolved and reprecipitated and so are resistant to weathering.

C) Rocks that are broken have more surface area and so weather faster.

D) Rocks that are easily weathered and eroded generally form steep cliffs.

E) None of these choices are correct.

19) Which of the following is true about how weathering affects fractured rocks?

A) Weathering affects rocks from the outside in, forming an outer weathered zone or rind.

B) Weathering attacks corners from three sides and so these are preferentially removed.

C) Preferential weathering along fractures can cause blocks to become rounded.

D) All of these choices are correct.

20) Which of the following are true about factors that influence weathering?

A) Chemical weathering occurs fastest in cold or dry climates.

B) Whether a slope faces toward or away from the sun is not an important factor influencing weathering.

C) Soil and other weathering products tend to accumulate more on gentle slopes than on steep slopes.

D) Time is not a critical factor in weathering because physical and chemical processes have not changed much through time.

21) All other factors being equal, a slope facing away from the Sun will tend to have

A) faster soil formation than the slope in direct sunlight, primarily because chemical weathering processes will be accelerated.

B) faster soil formation than the slope in direct sunlight, primarily because physical weathering processes will be accelerated.

C) slower soil formation than the slope in direct sunlight, primarily because chemical weathering processes will be slower.

D) slower soil formation than the slope in direct sunlight, primarily because physical weathering processes will be slower.

22) Compared to a gentle slope, a steep slope will have a

A) faster rate of soil formation and less soil.

B) slower rate of soil formation and less soil.

C) faster rate of soil formation and more soil.

D) slower rate of soil formation and more soil.

23) Lichens play a special role in chemical weathering by

A) weakening the hydrogen bond in water, making it more effective at dissolving rocks with high quartz concentrations.

B) slowing the rate of jointing in rocks.

C) acting as a catalyst for dissolution of minerals that crystallize at the highest temperatures.

D) secreting oxalic acid, which dissolves carbonates particularly well.

24) Why does weathering of granite bedrock produce rounded shapes?

A) The rounded shapes are pillows formed at depth in the granitic magma.

B) Weathering removes corners and edges, as in spheroidal weathering.

C) Burrowing animals eat away parts of the granite.

D) Roots rub against the edges of the granite.

25) Which of the following weathering processes results in the reddish orange coating on rocks, in soils, and on metal (rust)?

A) oxidation

B) salt crystallization

C) freeze thaw

D) differential weathering

26) Which of these four numbered features on the surface or in a cave are formed by the precipitation of calcium carbonate, due to the evaporation of water?

A) 1 and 2

B) 2 and 3

C) 3 and 4

D) 1 and 3

E) 1 and 4

27) Which of these four numbered features on the surface or in a cave can be formed by the dissolution or collapse of limestone?

A) 1 and 2

B) 2 and 3

C) 3 and 4

D) 1 and 3

E) 1 and 4

28) Which of these four numbered features on the surface or in a cave is a stalagmite?

A) 1

B) 2

C) 3

D) 4

E) None of these choices are correct.

29) Which of these four numbered features on the surface or in a cave is a stalactite?

A) 1

B) 2

C) 3

D) 4

E) None of these choices are correct.

30) What rock type is the most common setting for caves formed by dissolution of a rock?

A) well-sorted sandstone

B) gray limestone

C) dark porous lava flows

D) gray granite

E) slate

31) Which of the following features is composed of calcium carbonate?

A) limestone

B) travertine

C) cave formations like stalagmites

D) All of these choices are correct.

32) Which of the following features is NOT formed by precipitation of calcite from water?

A) travertine

B) stalagmite

C) stalactite

D) sinkhole

E) flowstone

33) Which of the following generally is true about caves formed by dissolution?

A) acidic waters dissolve feldspar in granite, producing clay

B) groundwater removed material from limestone

C) hot geothermal waters introduce acids into shallow rocks

D) carbon dioxide rises from depth and dissolves calcite and clay

34) Which of the following is a feature that commonly forms where limestone has been dissolved?

A) sinkhole

B) karst topography

C) cave

D) All of these choices are correct.

35) Which sequence of events is required to form a limestone cave where you can walk around and observe cave formations, such as stalactites?

A) Limestone is below the water table, then lowering of the water table, then water dripping from the ceiling.

B) Lowering of the water table, then water dripping from the ceiling, then limestone is below the water table.

C) Water dripping from the ceiling, then lowering of the water table, then limestone is below the water table.

D) None of these choices are correct.

36) What is the most common way in which sinkholes form?

A) a small explosion of methane gas from coal beds

B) a small explosion of CO2 gas from dissolving limestone

C) a rising dome of salt finally reaches the surface

D) the roof of a cave collapses

37) Which of the following is the best indication that limestone caves could be present at depth?

A) springs

B) cliffs and overhangs along rivers

C) large quartz crystals laying on the surface

D) gently sloping hills

E) limestone pillars and sinkholes

38) Which of the following features is formed by the collapse of caves?

A) travertine

B) stalagmite

C) stalactite

D) sinkhole

E) flowstone

39) In which setting is karst topography most likely to feature steep pillars, knobs, and oddly shaped rocks?

A) tropical

B) arid

C) mid-latitude

D) polar

40) Aside from limestone, which other kinds of rock types produce karst terrain?

A) evaporite rocks such as salt and gypsum

B) granite

C) sandstone

D) shale

41) The largest area of karst in the United States is included in

A) Florida.

B) Mississippi.

C) Minnesota.

D) Texas.

42) Which of the numbered soil horizons are most likely to represent an accumulation of organic debris?

A) 1 and 2

B) 2 and 3

C) 3 and 4

D) 4 and 5

E) All of these choices are correct.

43) Which of the numbered soil horizons is most likely to have remnants of weathered bedrock?

A) 1

B) 2

C) 3

D) 4

E) 5

44) Which of the numbered soil horizons is most likely to have clay or calcium carbonate?

A) 1

B) 2

C) 3

D) 4

E) 5

45) Which of the following is NOT a source of material for soil?

A) weathered rock and sediment

B) leaves and other plant debris

C) CO2 gas from roots

D) water from precipitation and snowmelt

E) All of these are a source of material in soil.

46) How does material in soil move?

A) The upper part of soil loses material downward.

B) Clay minerals and other fine particles are carried downward.

C) Chemical ions leached from above can accumulate in the underlying zone.

D) Calcium carbonate can accumulate in the soil, especially in dry environments.

E) All of these choices are correct.

47) A soil that has little or no O-horizon but a thick accumulation of calcium carbonate (caliche) most likely forms in

A) a tropical climate.

B) a temperate climate.

C) an arid climate.

D) an area with abundant rainfall.

E) a short amount of time.

48) Soil that is reddish, intensely leached, and rich in iron and aluminum minerals most likely forms in

A) tropical climate.

B) temperate climate.

C) arid climate.

D) an area with only minor soil development.

E) a short amount of time.

49) What is the main process by which soils form?

A) deposition of silt on a floodplain

B) deposition of silt by the wind

C) weathering

D) erosion

50) People reshape steep slopes, a practice called terracing, in order to

A) help capture and retain rainfall.

B) provide a level place on which to farm.

C) promote soil formation.

D) protect soil from erosion.

E) All of these choices are correct.

51) Which of the following are problems related to soil?

A) individual grains lose contact with one another as water squeezes between them

B) certain clay minerals increase in volume when they become wet

C) soils that do not compact uniformly because of varying amounts of clay

D) erosion due to loss of plant cover, such as from overgrazing

E) All of these choices are correct.

52) How can weathering form a mineral deposit?

A) Extreme leaching can leave behind elements, such as aluminum, that are valuable.

B) Weathering can dissolve copper from the top of a mineral deposit and reprecipitate it at depth.

C) Heavier materials, such as gold and diamond, accumulate near the base of river gravels.

D) All of these choices are correct.

53) The main feature shown in this photograph illustrates

A) weathering.

B) flooding.

C) permafrost.

D) slope failure.

54) As illustrated in this figure, which of the following is NOT a potential trigger for slope failure?

A) precipitation that can saturate and weaken sediment

B) undercutting of steep slopes by roads and rivers

C) shaking during an earthquake

D) shaking of slopes and melting of snow during volcanic eruptions

E) All of these are potential triggers for slope failure.

55) What is the main force involved in the stability of slopes?

A) water pressure

B) sunlight

C) wind

D) gravity

E) radioactivity decay

56) What is the angle of repose?

A) The angle of bedding on hills where layers dip parallel to the slope.

B) The angle of fractures on hills where fractures dip parallel to the slope.

C) The angle at which rainfall strikes an unstable slope.

D) The steepest angle at which loose material remains stable.

57) Which of the following is NOT a common trigger for slope failure?

A) adding water to a slope

B) volcanic eruption

C) shaking during an earthquake

D) oversteepening of cliffs or hillslopes during road construction

E) All of these are common triggers for slope failure.

58) Which of the following is an expression of the angle of repose?

A) talus slope

B) some slopes of sand dunes

C) angle of slopes on scoria cones

D) All of these choices are correct.

59) Which of the following factors does NOT control the stability of a slope?

A) the angle of repose for intact bedrock

B) whether the slope is rock or soil

C) the amount of water in the soil

D) the orientation of fractures, cleavage, and bedding

60) Which of the following factors is typically NOT used to classify slope failures?

A) whether the material involved is rock or is unconsolidated

B) the rate of movement

C) the climate in which the failure occurs

D) the mechanism by which material moves

61) Which of the following is a way that slopes fail?

A) Large blocks fall from cliffs.

B) Rocks, soil, sediment, and ice slides down steep hillsides.

C) Pieces of loose rock accumulate on talus slopes until the angle becomes too steep.

D) Soil and other loose material can flow rapidly down slopes, forming debris flows.

E) All of these choices are correct.

62) What type of slope failure is shown in this figure?

A) debris avalanche

B) creep

C) rock slide

D) debris flow

E) rock fall

63) Which of the following factors favors movement of a rock slide?

A) layers that are inclined opposite to the slope of the hill

B) solid rock with few preexisting joints or faults

C) a massive rock with no bedding or other through-going discontinuities

D) a valley or other open space downslope from the rock slide

64) Which numbered feature on this figure is a scarp?

A) 1, a linear or curved scar marking where the slide pulled away from the hill

B) 2, small fractures within the sliding block

C) 3, the intact layers below the rock slide

D) 4, the front of the slide, where it overruns the land surface

E) 5, a valley or other open space in front of the slide

65) Which numbered feature on this figure is critical to enable a rock slide to start?

A) 1, a linear or curved scar marking where the slide pulled away from the hill

B) 2, small fractures within the sliding block

C) 3, layers, fractures, or some other discontinuity inclined downslope

D) 4, the front of the slide, where it overruns the land surface

E) 5, a valley or other open space in front of the slide

66) What factors lead to the Viaont landslide disaster?

A) A volcanic eruption shook the ground.

B) A major earthquake shook the ground.

C) The sedimentary layers dipped downslope toward the reservoir.

D) All of these choices are correct.

67) What type of slope failure is shown in this figure?

A) rotational slide

B) creep

C) earth flow

D) debris flow

E) rock fall

68) What type of slope failure is shown in this figure?

A) rotational slide

B) creep

C) rock avalanche

D) debris flow

E) rock fall

69) The main feature shown in this photograph illustrates?

A) weathering

B) flooding

C) permafrost

D) slope failure

70) The type of slope failure shown in this photograph is

A) creep.

B) a rock slide.

C) a debris avalanche.

D) a debris flow.

E) All of these choices are correct.

71) What type of slope failure is shown in this figure?

A) rotational slide

B) creep

C) earth flow

D) debris flow

E) rock slide

72) What type of slope failure is shown in this figure?

A) rotational slide

B) creep

C) debris slide

D) debris flow

E) rock fall

73) What type of slope failure is shown in this figure?

A) rotational slide

B) creep

C) earth flow

D) debris flow

E) rock avalanche

74) Which of the following slope failures is least likely to cause casualties?

A) rock avalanche

B) debris flow

C) creep

D) rock slide

E) rock fall

75) Which of the following slope failures moves at the slowest rate?

A) earth flow

B) rock avalanche

C) debris flow

D) rock fall

E) debris avalanche

76) Which of the following slope failures is most likely to cause large numbers of casualties?

A) creep

B) debris slide

C) earth flow

D) rotational slide

E) rock avalanche

77) What type of slope failure is shown in this figure?

A) creep

B) debris flow

C) rock fall

D) rock slide

E) rotational slide

78) What type of slope failure is depicted in this photograph?

A) creep

B) rock fall

C) debris avalanche

D) permafrost

79) Which of the following has the lowest potential for landslides?

A) Pacific Northwest

B) Southern California

C) bluffs along rivers in the central U.S.

D) Florida

E) Appalachian Mountains

80) Which of the following factors caused some high peaks of the Cascade Mountains of the Pacific Northwest to have high potential for slope failure?

A) They are volcanoes with steep slopes.

B) They experience heavy rainfall.

C) They may contain loose volcanic ash and other volcanic materials.

D) All of these choices are correct.

81) The landslide that destroyed La Conchita, as shown in this photograph, is probably

A) an example of creep.

B) an earth flow.

C) a rock fall.

D) a rock avalanche.

82) For La Conchita, California, what type of slope failure occurred?

A) rock avalanche

B) debris flow

C) creep

D) rock fall

E) earth flow

83) Which of the following might indicate that slopes adjacent to this landslide might fail?

A) They have the same steepness as the slope that failed.

B) They appear to have a similar geology setting.

C) One part of the slope has already failed.

D) All of these choices are correct.

84) Which of the following can we use to recognize prehistoric slope failures?

A) sedimentary deposits

B) orientation of beds and other geologic structures

C) masses of rock fragments that are unusual for an area

D) hummocky topography

E) All of these choices are correct.

85) Which of the following is probably NOT important in assessing an area's potential for slope failure?

A) comparing the geologic setting to adjacent areas that have or have not failed

B) whether the material is loose sediment or solid bedrock

C) recent changes in slope

D) the orientation of layering and fractures

E) All of these are important.

86) What type of slope failure has occurred in the Slumgullion area of Colorado?

A) a huge rock fall that formed Colorado's second largest lake

B) a debris flow that came down Big Thompson Canyon

C) a debris avalanche that raced downhill at breathtaking speeds

D) a slow-moving earth flow

87) The USGS evaluated the age of different parts of the Slumgullion feature by

A) measuring the size of trees incorporated into the material.

B) measuring the temperature of rocks soon after the feature had moved.

C) examining the development of soil.

D) measuring the content of moisture during different seasons.

E) None of these choices are correct.

88) What did the USGS discover when they studied the Slumgullion feature?

A) There were different parts with different ages.

B) Movement formed folds, faults, fissures, and zones of shearing.

C) Some parts of the material moved faster than other parts.

D) All of these choices are correct.

89) Which of the following areas in the investigation terrain is least likely to cause casualties in the event of a slope failure?

A) Bent Fence Hills with the leaning trees

B) flanks of Flattop Hill

C) Rock Valley

D) the area below Tilted Mountain

90) Which area would most likely cause the least problems with keeping roads in good shape?

A) Bent Fence Hills

B) Wild Ride Valley

C) the flat area above the river terraces

D) a road built directly below the cliffs of Flattop Mountain

91) Which of the following is the main hazard for areas along the river terrace?

A) shrinking and swelling of clays

B) slow movement of material downslope

C) rock falls

D) debris flows that carry large blocks from the volcano

92) On this image are 5 houses. Their roofs are labeled A through E. Choose the house that has the smallest hazard of being damaged by slope failure.

A) A

B) B

C) C

D) D

E) E