chap10

Elemental Geosystems, 5e (Christopherson)Chapter 10 Weathering, Karst Landscapes, and Mass Movement

1)

The science that specifically studies the origin, evolution, form, and spatial distribution of landforms is A)

geology. B)

geography. C)

geomorphology. D)

environmental chemistry. Answer:

C

2)

All processes that cause the wearing away or rearrangement of landforms are included in the term A)

mass movement. B)

mass wasting. C)

weathering. D)

denudation. Answer:

D

3)

The uplift of mountains is caused by A)

endogenic processes. B)

aggradation. C)

denudation. D)

exogenic forces. Answer:

A

4)

If the earth did not experience endogenic processes, the landscape would A)

be rugged and of great relief as a result of uplift in the absence of weathering and erosion. B)

consist of high mountains and hills with smooth, gentle slopes. C)

be of very low relief as a result of weathering and erosion in the absence of uplift. Answer:

C

5)

Which of the following is not exogenic in nature? A)

weathering B)

erosion C)

denudation D)

batholith formation E)

mass wasting Answer:

D

6)

Which of the following was not suggested by William Morris Davis in his model of landscape evolution? A)

Uplift is followed by erosion. B)

Streams initially erode rapidly both in the headward direction and downward due to the high relief of the initial landscape.

C)

Slope angles and divides become steeper through time. D)

All of these were suggested by Davis. Answer:

C

7)

The form that a landscape exhibits results from a balance between A)

forces acting on the landscape. B)

endogenic and exogenic processes. C)

inputs and outputs of matter and energy. D)

all of the above Answer:

D

8)

The dynamic equilibrium model refers to A)

a balancing act between tectonic uplift and rates of reduction by weathering and erosion in a given landscape.

B)

a theory involving the cyclic or evolutionary development of a landscape. C)

a sequential development of landforms. D)

an important concept first stated by William Morris Davis. Answer:

A

9)

In reality, a landscape behaves as A)

a closed system. B)

an open system. C)

an evolutionary model changing in a sequence of stages that is the same everywhere on the earth. D)

a closed system in terms of energy and an open system in terms of matter. Answer:

A

10)

If material is to move downslope, it must overcome the force of A)

friction. B)

the cohesion of particles to each other. C)

inertial resistance of the material. D)

all of these Answer:

D

11)

Uplift of the landscape creates ________ energy which is converted to ________ energy when materials begin to move downslope.

A)

kinetic; potential B)

potential; kinetic C)

potential; chemical D)

kinetic; chemical Answer:

B

12)

After a threshold is crossed, the landscape A)

remains unstable thereafter. B)

adjusts to a new equilibrium condition. C)

looks identical to the landscape that existed prior to the crossing of the threshold. D)

Any of these are equally likely to occur. Answer:

B

13)

Conflicting forces work to establish an optimum incline on a slope. When any of these conditions are disturbed or altered, the materials on the slope reach a

A)

condition of static equilibrium. B)

condition of metastable equilibrium at the time of disturbance. C)

geomorphic cycle. D)

geomorphic threshold, or change point. Answer:

D

14)

Movement at the geomorphic threshold signals A)

a conversion of potential energy to kinetic energy. B)

a conversion of kinetic energy to chemical energy. C)

frictional resistance overcoming the degree of cohesion. D)

a lack of change. Answer:

A

15)

The convex upper portion of a typical slope is called a A)

pediment. B)

debris slope. C)

waxing slope. D)

free face. Answer:

C

16)

On which part of a slope would rocks tend to fall at the highest speeds? A)

waning slope B)

waxing slope C)

debris slope D)

free face Answer:

D

17)

The disintegration and dissolving of surface and subsurface rock is called A)

erosion. B)

mass wasting. C)

landmass denudation. D)

weathering. Answer:

D

18)

Which of the following is false regarding joints? A)

Joints are small, localized fault planes along which movement occurs. B)

Joints enable more water to move through the ground.

C)

Joints enhance the rate of weathering. D)

All of these are true. Answer:

A

19)

In the Northern hemisphere mid-latitudes, slopes that face ________ have more trees on them because ________.

A)

south; they receive more direct sunshine for photosynthesis B)

south; they receive more rainfall C)

north; they are more moist D)

north; they receive more direct sunshine Answer:

C

20)

Chemical weathering is greatest under conditions of A)

higher mean annual rainfall and temperatures. B)

lower mean annual rainfall and temperatures. C)

temperatures below freezing. D)

rainfall of less than 25 cm (10 in) per year. Answer:

A

21)

In which of the following climates would the subsurface line of contact between weathered and unweathered materials be at the greatest depth?

A)

cold and wet B)

cold and dry C)

hot and wet D)

hot and dry Answer:

C

22)

The rate at which rocks weather depends upon A)

the climate of an area. B)

the type of rock. C)

the amount of vegetation in an area. D)

all of the above E)

the climate of an area and the type of rock only. Answer:

D

23)

Physical weathering is greatest under conditions of A)

lower temperatures and higher precipitation.

B)

higher temperatures and precipitation, wetter, warmer climates. C)

a lack of moisture at the surface. D)

temperatures that reach below freezing. Answer:

D

24)

Other than the rock itself, the most important chemical substance needed for the majority of weathering processes is

A)

oxygen. B)

nitrogen. C)

water. D)

carbon dioxide. Answer:

C

25)

In most areas, the upper surface of bedrock is partially weathered to broken-up rock called A)

parent rock. B)

bedrock. C)

sediment. D)

regolith.

Answer:

D

26)

When rock is broken and disintegrated without dissolving, the process in operation is A)

physical weathering. B)

chemical weathering. C)

hydrolysis. D)

carbonation. Answer:

A

27)

Which of the following is not a type of physical weathering process? A)

exfoliation B)

hydrolysis C)

salt crystal growth D)

frost wedging Answer:

B

28)

The fact that water expands as much as 9 percent of its volume as it freezes is the basis of A)

chemical weathering processes.

B)

pressure-release jointing. C)

crystallization. D)

frost wedging. Answer:

D

29)

The dramatic domes and arch-shaped features found in granitic mountain masses result from A)

solution processes. B)

frost-wedging. C)

pressure-release jointing, exfoliation, and sheeting. D)

spheroidal weathering. Answer:

C

30)

The large sheets of rock that break off batholiths, such as Half Dome in Yosemite National Park, develop as a result of

A)

exfoliation. B)

mineral expansion. C)

salt crystal growth. D)

frost wedging. Answer:

A

31)

Exfoliation occurs because A)

water combines with minerals and increases their size, thereby causing surrounding minerals to pop out of the rock matrix.

B)

water freezes in joints and expands.

C)

overlying rock is removed, thereby allowing the underlying rock mass to expand. D)

All of the above are possible causes of exfoliation. Answer:

C

32)

Hydration involves A)

a chemical weathering process. B)

swelling and stress within a rock with the addition of water. C)

frost action. D)

the action of wind. Answer:

B

33)

Which type of weathering is limited to arid environments? A)

exfoliation B)

frost wedging C)

hydrolysis D)

salt crystal growth E)

carbonic acid solution

Answer:

D

34)

Which of the following is true of spheroidal weathering? A)

It is a physical weathering process. B)

It is a type of exfoliation associated with pressure release. C)

It attacks the corners and edges of rocks. D)

All of these are true. Answer:

C

35)

Which of the following are the principal active agents involved in chemical weathering? A)

oxygen, silicon, aluminum B)

magnesium, water, limestone C)

water, oxygen, carbon dioxide D)

nitrogen, oxygen, argon Answer:

C

36)

An example of chemical weathering is A)

exfoliation.

B)

the breakdown of rocks by freezing and thawing. C)

the wearing away of a stream bank by a river. D)

the limestone formations of Carlsbad Caverns in New Mexico. Answer:

D

37)

Hydrolysis involves A)

no actual chemical change in minerals. B)

water being added to a mineral leading to swelling and stress in rock. C)

water chemically combining with minerals. D)

hydraulic action of water between rocks. Answer:

C

38)

Which is true of hydrolysis? A)

It involves silicate minerals. B)

It involves the chemical reaction of water with a mineral. C)

It produces clays D)

All of the above are true.

E)

Only A and B are true. Answer:

D

39)

The yellow-red stains that occur on some rock surfaces are the result of ________, which is a form of ________ weathering.

A)

hydration; physical B)

hydration; chemical C)

solution; chemical D)

oxidation; physical E)

oxidation; chemical Answer:

E

40)

Karst topography is formed primarily by A)

carbonic acid solution. B)

mass wasting processes. C)

oxidation and hydrolysis. D)

exfoliation and hydration. Answer:

A

41)

Concrete that is buried below the ground will usually weather faster than that above ground. This is because

A)

carbonic acid solution attacks the concrete. B)

water is more abundant in the soil. C)

exfoliation is more likely to occur below ground level. D)

carbonic acid solution attacks the concrete and water is more abundant in the soil only. E)

all of these Answer:

D

42)

Which of the following is not necessary for well-developed karst to develop? A)

high proportion of calcium carbonate in the rock B)

joints in rock of low permeability C)

vegetation D)

arid conditions Answer:

D

43)

The weathering of limestone can create circular depressions known as A)

uvalas.

B)

stalactites. C)

sinkholes. D)

caverns. Answer:

C

44)

Cave formations develop from the precipitation of A)

calcite. B)

halite. C)

phosphate. D)

sulfate. Answer:

A

45)

Which of the following countries is noted for its spectacular tower karst? A)

Russia B)

the U.S. C)

China D)

France

Answer:

C

46)

Which of the following is incorrectly matched? A)

stalagmite formation built up from a cave floor B)

sinkhole doline C)

karst towers formations created by the merging of stalactites and stalagmites D)

complex landscape of intersecting dolines cockpit karst Answer:

C

47)

All unit movement of materials propelled and controlled by gravity are referred to as A)

lahars. B)

downslope flows. C)

mass movements or mass wasting. D)

slides. Answer:

C

48)

The steepness of a slope of loose material at rest is the A)

height of the slope.

B)

angle of repose. C)

mass movement gradient. D)

the speed of the particles. Answer:

B

49)

One side of a sand dune is typically steeper than the other side. The slope of the steepest is controlled by the angle of repose for sandwhich has a value that is typical for most materials. This angle is about ________.

A)

5 degrees B)

15 degrees C)

34 degrees D)

78 degrees Answer:

C

50)

If you have ever played on a beach and made a sand castle, you used wet sand rather than dry sand. You did this because the ________ of wet sand is greater than that of dry sand.

A)

angle of repose B)

cohesiveness C)

gravity D)

cohesiveness and gravity E)

angle of repose and cohesiveness Answer:

E

51)

Landslides occur when A)

a threshold is reached. B)

the internal friction is overcome by the force of gravity. C)

when driving forces exceed resisting forces. D)

all of the above E)

B and C only Answer:

D

52)

In the Andes Mountains of South America, entire towns of thousands of people have been buried suddenly when snow fell from high on a mountain side, melted on impact, and then mixed with loose

materials that traveled downhill as a viscous fluid. This type of catastrophic event is known as a A)

lahar. B)

slump. C)

rock fall. D)

slide. E)

debris avalanche. Answer:

E

53)

Which of the following might be expected to occur in an ash-covered, mountainous volcanic region following a heavy rain?

A)

lahar B)

slump C)

rockslide D)

creep E)

debris avalanche Answer:

A

54)

A landslide differs from a debris avalanche in that A)

the materials in a landslide are not saturated with water. B)

the materials in a debris avalanche are not saturated with water. C)

a land slide moves much more slowly than a debris avalanche. D)

a land slide moves much more quickly than a debris avalanche. Answer:

A

55)

A translational slide involves A)

rotational movement of surface material. B)

movement of surface material along a planar surface. C)

unconsolidated flow of material. D)

mudflow. Answer:

B

56)

The engineers who built the Vaiont Reservoir in Italy should have anticipated the possibility of a ________ because the valley in which the dam was located had hillsides made of sedimentary rock that tilted downslope toward the reservoir.

A)

translational slide B)

rotational slide C)

lahar D)

debris avalanche Answer:

A

57)

A persistent mass movement of surface soil is called a A)

debris avalanche. B)

soil creep. C)

soil slide. D)

rockfall. Answer:

B

58)

In 1973, part of the flat ground on which a subdivision was located became saturated and began to flow toward the Saint Lawrence River at speeds of up to 26 kmph (16 mph). The ground that flowed consisted of silts and claysnot large, rocky regolith. What type of mass wasting event was this?

A)

debris avalanche B)

soil creep C)

Earth flow D)

lahar Answer:

C

59)

Which of the following can initiate hillslope failure? A)

making a roadcut in the side of a hill B)

increasing the slope angle C)

excessively watering a slope D)

all of these Answer:

D

60)

Human-induced mass movements produce a category of processes known as A)

debris flows. B)

mass wasting. C)

scarification. D)

translational slides. Answer:

C

61)

The balancing act between tectonic uplift and reduction of the landscape by weathering and erosion, between the resistance of crust materials and the attack of denudation processes, is summarized in the dynamic equilibrium model.

Answer:

True

False

62)

The model of landscape evolution developed by William Morris Davis is still widely regarded as the most accurate model of landscape evolution yet developed.

Answer:

True

False

63)

The dynamic equilibrium model of landscape evolution emphasizes a balance among forces, form and processrather than cyclical stages of development.

Answer:

True

False

64)

If a landscape is evolving toward a threshold condition, this means that it is approaching a condition of stability.

Answer:

True

False

65)

A landscape in a state of dynamic equilibrium experiences no change. Answer:

True

False

66)

Iron oxidation produces red and yellow stains on rocks. Answer:

True

False

67)

Mass wasting occurs when gravity overcomes friction. Answer:

True

False

68)

Physical and chemical weathering processes are not separatethey often operate in concert to decompose and dissolve rock.

Answer:

True

False

69)

Physical weathering dominates in warm, wet climates. Answer:

True

False

70)

Karst topography involves the chemical weathering of granite landscapes. Answer:

True

False

71)

All karst landscapes go through the same stages of development. Answer:

True

False

72)

The radio telescope in Arecibo is set in a landscape formed by chemical weathering processes. Answer:

True

False

73)

Dripstone formations in caves develop while the caves are full of groundwater. Answer:

True

False

74)

A landslide designation is used when substantial amounts of water are saturated in the mass of materials. Answer:

True

False

75)

Soil creep is a natural process sometimes related to a freeze-thaw cycle of soil moisture. Answer:

True

False

76)

Carlsbad Caverns was produced by exogenic processes. Answer:

True

False

77)

Soil thickness will decrease when soil production rates are greater than soil erosion rates. Answer:

True

False

78)

The angle of repose of snow avalanche slopes is typically higher than that for soil or rock. Answer:

True

False