Deck 6: Weathering, Erosion, and Soil

Question 1

List some ways in which organisms contribute to mechanical weathering.

Answer 1

burrowing/particle mixing/root wedging/reduction of particle size

Question 2

Name an important physical property about water that makes it unique among liquids,and why is this property important in the weathering of rocks?

Answer 2

It increases in volume when it freezes (changes from a liquid to a solid state).The expanding volume creates pressures which may break rocks and minerals into smaller pieces.

Question 3

Define weathering.

Answer 3

Weathering is the physical disintegration and/or chemical decomposition of rocks at or near Earth's surface as they are exposed to the atmosphere,hydrosphere,and/or biosphere.

Question 4

Briefly explain how exfoliation domes form.

Question 5

How does mechanical weathering differ from chemical weathering?

Question 6

List the agricultural practices which reduce the rate of soil erosion and explain why each does so.

Question 7

What factors and sequence of events commonly lead to soil erosion in rainforests?

Question 8

How can organisms contribute to chemical weathering?

Question 9

In what climatic conditions is frost action most effective?

Question 10

Explain why the ferromagnesian minerals most susceptible to chemical weathering are those formed early in the continuous branch of Bowen's reaction series.

Question 11

How does loss of soil fertility exacerbate soil erosion?

Question 12

Explain why,and give two examples of how,climate is more effective in determining soil type than parent rock type.

Question 13

Briefly explain why water is such an important agent in chemical weathering.

Question 14

How do soils that form in semi-arid to arid regions differ in their basic characteristics from soils that form in humid regions?

Question 15

What processes lead to soil degradation?

Question 16

How does weathering differ from erosion?

Question 17

Briefly explain the sequence in which a soil develops.

Question 18

What environmental effects are being seen that result from acid rain? In which environments are these effects lessened? Where are they most seen?

Question 19

List some examples of mechanical weathering processes.

Question 20

Describe the human activities that produce acid rain.

Question 21

Any process that removes soil or makes it less productive is called _______ _______.

Question 22

Three important chemical processes involved in chemical weathering are ____________________,____________________,and ____________________.

Question 23

Weathering is an essential part of the _______ _______ because parent material must break down into smaller pieces or perhaps dissolve to become sediment.

Question 24

What factors lead to the development of the "Dust Bowl" during the 1930s in the United States?

Question 25

A(n)____________________ soil forms where the parent material has weathered,whereas ____________________ soil develops from eroded material that was weathered at another location.

Question 26

What are the principle controls on soil formation?

Question 27

Briefly explain how hydrolysis results in the weathering of some minerals.

Question 28

The process that decomposes rocks and minerals by altering the makeup of the parent material is called _______ _______.

Question 29

How does mechanical weathering aid chemical weathering?

Question 30

How does regolith differ from soil?

Question 31

Carbon dioxide levels in the atmosphere are rising due to the burning of fossil fuels.How might this increased level of carbon dioxide affect rates of weathering?

Question 32

Why do small particles weather more rapidly than large particles?

Question 33

The chemical weathering process that produces most of the red,yellow,and brown colors seen in soils and many sedimentary rocks is called ____________________.

Question 34

____________________ is an essential component of soil as it provides nutrients to plants and increases the ability of the soil to retain ____________________.

Question 35

Soils that are a result of intense weathering and are typically found in the tropics are ____________________.

Question 36

Large,rounded masses of rock from which joint-bounded slabs of rock have slipped off are _______ _______.

Question 37

Carbonate minerals,like calcite,dissolve readily in a solution that is _______.

Question 38

What is soil degradation?

Question 39

What three types of soil degradation are recognized?

Question 40

What are the major factors that control the rate of chemical weathering?

Question 41

On a pH scale,the pH value of something neutral is _______; the pH of normal rain is _____ and acid rain is less than _____.

Question 42

The important weathering product(s)of hydrolysis of feldspar is (are)____.

A) ferromagnesian minerals
B) sand minerals
C) dissolved calcium
D) clay minerals
E) accessory minerals

Question 43

The actions of ____________________ and ____________________ are responsible for most soil erosion.

Question 44

Which of the following is a means of mechanical weathering?

A) frost wedging
B) pressure release
C) thermal expansion and contraction
D) burrowing and root wedging
E) all of these

Question 45

Hydrolysis is particularly effective in weathering ____.

A) limestone
B) sandstone
C) quartz
D) calcite
E) feldspar

Question 46

____________________ erosion occurs when water carves small channels into a soil bed.

Question 47

Weathering that takes place at different rates even in the same area is called

A) mechanical weathering.
B) differential weathering.
C) chemical weathering.
D) original weathering.

Question 48

The most important factor controlling soil formation is ____________________.

Question 49

What is erosion?

A) movement of weathered material from its source site
B) decomposition of rock
C) disintegration of rock
D) weathering of rock and transportation of sediment
E) disintegration of soil

Question 50

Frost wedging in the mountains produces which type of material?

A) tailings
B) talus
C) conglomerate
D) exfoliation
E) regolith

Question 51

Which of the following is not a factor influencing the rate of chemical weathering?

A) climate
B) particle size
C) parent material
D) humidity
E) gravity

Question 52

Because quartzite is (more/less)____________________ chemically stable than granite,it will be covered by a (thicker/thinner)____________________ layer of soil than will an adjacent body of granite.

Question 53

Weathering is classified into which of the following categories?

A) mechanistic and compositional
B) mechanical and physical
C) chemical and physical
D) physical and chemical
E) organic and inorganic

Question 54

Under similar climatic conditions,soil will develop (faster/slower)____________________ on solid bedrock than it will on unconsolidated sediment.

Question 55

What does pressure release weathering result in?

A) sheet jointing
B) rock bursts
C) exfoliation
D) exfoliation domes
E) all of these

Question 56

Which of the following contribute to weathering?

A) organisms such as worms, bacteria, and trees
B) oxygen and carbon dioxide in the air
C) rain water
D) organic acids
E) all of these

Question 57

Thermal expansion and contraction occur most commonly in which of the following conditions?

A) cold and hot
B) arid and cold
C) humid and hot
D) arid and hot
E) humid and cold

Question 58

Under which conditions does pressure release occur?

A) humid and seasonal
B) hot and arid
C) cold and humid
D) where there is uplift and erosion
E) where there is faulting and seismic activity

Question 59

The economically valuable mineral resource produced by intense chemical weathering that is found only in laterite soils is called ____________________.

Question 60

What is a source of carbon dioxide for carbonic acid?

A) the atmosphere
B) soil
C) groundwater
D) surface water
E) all of these

Question 61

In soil,the A horizon is

A) low in organic matter.
B) the site of little biological activity.
C) full of sand and gravel.
D) composed mostly of clays and stable minerals.

Question 62

Sheet joints,created by pressure release,form roughly parallel to the rock surface.

Question 63

A rock may be subjected to either mechanical or chemical weathering but never both at the same time.

Question 64

Salt crystals can exert enough force to widen cracks and dislodge particles in some rocks.

Question 65

Laterite soils are not very fertile.

Question 66

Carbonic acid forms from the combination of

A) water and bicarbonate ion.
B) water and carbon dioxide.
C) carbon dioxide and hydrogen ion.
D) calcium ion and bicarbonate ion.

Question 67

Laterite soils are the product of intense leaching.

Question 68

What is caliche?

A) a layer of silica cement within a pedalfer
B) a layer of precipitated calcium carbonate in horizon B
C) a layer of rock between soil layers C and D
D) a deposit formed in alkali soils
E) a light colored layer of unstable minerals

Question 69

Laterite soils can support extended periods of farming.

Question 70

Acid rain is a problem in regions near the source of the emissions but,unlike global warming,it is not a worldwide problem.

Question 71

The most stable shape a stone can form is a rectangle.

Question 72

Hydrolysis is the chemical reaction between a mineral's ions and

A) water molecules.
B) hydrogen and oxygen ions.
C) hydrogen and hydroxyl ions.
D) hydroxide ions.

Question 73

Pressure release is a mechanical weathering process that occurs often in intrusive rocks such as those formed in batholiths.

Question 74

Laterite soils are typical of rainforests.

Question 75

Clay particles in soil are important to soil development because ____.

A) They hold soil particles apart.
B) They allow water and gases to enter soil.
C) They retain water and supply nutrients.
D) They allow the flow of groundwater.
E) They drain poorly.

Question 76

Thermal expansion and contraction occur because rock is an excellent conductor of heat.

Question 77

Mechanical weathering produces no change in the chemical composition of the parent rock.

Question 78

Humus ____.

A) is the material always comprising the topmost soil horizon
B) is dark, organic-rich material formed by bacterial decay
C) is leaf-litter
D) must include sediments
E) none of these

Question 79

Laterite soils are rich in organic matter.

Question 80

The biggest problem areas for acid rain include

A) the eastern United States and much of Europe.
B) China and Australia.
C) western Europe and the western United States.
D) the Amazon, Congo and Pacific rainforests.