Deck 10: Weathering, Karst Landscapes, and Mass Movement

Question 1

Which of the following is not exogenic in nature?

A) weathering
B) erosion
C) denudation
D) batholith formation
E) mass wasting

Answer 1

D

Question 2

The uplift of mountains is caused by

A) endogenic processes.
B) aggradation.
C) denudation.
D) exogenic forces.

Answer 2

A

Question 3

If 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 3

C

Question 4

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

Question 5

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.

Question 6

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

A) geology.
B) geography.
C) geomorphology.
D) environmental chemistry.

Question 7

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 Earth.
D) a closed system in terms of energy and an open system in terms of matter.

Question 8

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

Question 9

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

Question 10

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.

Question 11

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.

Question 12

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.

Question 13

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.

Question 14

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

Question 15

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

Question 16

The disintegration and dissolving of surface and subsurface rock is called

A) erosion.
B) mass wasting.
C) landmass denudation.
D) weathering.

Question 17

The dynamic equilibrium model refers to

A) a balancing act between tectonic uplift and rates of reduction 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 John Powell.

Question 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.

Question 19

The convex upper portion of a typical slope is called a

A) pediment.
B) debris slope.
C) waxing slope.
D) free face.

Question 20

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

Question 21

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.

Question 22

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.

Question 23

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.

Question 24

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.

Question 25

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.

Question 26

Karst topography is formed primarily by

A) carbonic acid solution.
B) mass wasting processes.
C) oxidation and hydrolysis.
D) exfoliation and hydration.

Question 27

Which of the following is a type of chemical weathering process?

A) exfoliation
B) hydrolysis
C) salt crystal growth
D) frost wedging

Question 28

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.

Question 29

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.

Question 30

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.

Question 31

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.

Question 32

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.

Question 33

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) A and B only
E) all of these

Question 34

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

Question 35

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

A) physical weathering.
B) chemical weathering.
C) hydrolysis.
D) carbonation.

Question 36

Which type of weathering is limited to arid environments?

A) exfoliation
B) frost wedging
C) hydrolysis
D) salt-crystal growth
E) carbonic acid solution

Question 37

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

Question 38

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.

Question 39

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.

Question 40

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.

Question 41

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.

Question 42

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

Question 43

Which of the following is $\underline {\text { not } }$ 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

Question 44

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.

Question 45

A persistent mass movement of surface soil is called a

A) debris avalanche.
B) soil creep.
C) soil slide.
D) rockfall.

Question 46

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.

Question 47

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

Question 48

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

A) Russia
B) the U.S.
C) China
D) France

Question 49

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

A) debris flows.
B) mass wasting.
C) scarification.
D) translational slides.

Question 50

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

Question 51

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

Question 52

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

Question 53

Cave formations develop from the precipitation of

A) calcite.
B) halite.
C) phosphate.
D) sulfate.

Question 54

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.

Question 55

The weathering of limestone can create circular depressions known as

A) uvalas.
B) stalactites.
C) sinkholes.
D) caverns.

Question 56

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 sand-which 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

Question 57

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.

Question 58

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

Question 59

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 clays-not large, rocky regolith. What type of mass wasting event was this?

A) debris avalanche
B) soil creep
C) Earth flow
D) lahar

Question 60

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.

Question 61

Mass wasting occurs when gravity overcomes friction.

Question 62

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

Question 63

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

Question 64

Of the world's largest rivers, which has the greatest discharge?

A) Zaire (Congo) River
B) Amazon River
C) Missouri-Ohio-Mississippi river system
D) Chang Chiang (Yangtze) of Asia

Question 65

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

Question 66

All karst landscapes go through the same stages of development.

Question 67

Iron oxidation produces red and yellow stains on rocks.

Question 68

Physical weathering dominates in warm, wet climates.

Question 69

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

Question 70

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

Question 71

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

Question 72

Karst topography involves the chemical weathering of granite landscapes.

Question 73

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

Question 74

A $\underline {\text { landslide } }$ designation is used when substantial amounts of water are saturated in the mass of materials.

Question 75

Carlsbad Caverns was produced by exogenic processes.

Question 76

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

Question 77

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

Question 78

C840(11)
Chapter 11 River Systems and Landforms

Question 79

At any one moment, approximately ________ of fresh water flows through Earth's rivers and streams.

A) 1,250 km³ (300 mi³)
B) 13,000 km³ (3,100 mi³)
C) 104,000 km³ (25,000 mi³)
D) 22 percent (an amount equal to that in groundwater)

Question 80

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