Deck 10: Weathering, Soil, and Erosion

Question 1

Soils with B horizons rich in accumulated aluminum, iron, and silicon are called __________.

Answer 1

pedalfers

Question 2

The removal of weathered material is __________.

Answer 2

erosion

Question 3

During __________, water dissolves a mineral to form a solution.

A) dissolution
B) hydrolysis
C) frost wedging
D) salt cracking

Answer 3

A

Question 4

When Mount St. Helens erupted, the meltwater from melting glaciers mixed with soil to form __________.

Question 5

__________ is the orientation of a slope with respect to the Sun.

Question 6

In a moist tropical climate, dissolved ions may be leached out of the soil, forming __________.

Question 7

During __________, rock or soil flows slowly downslope under the influence of gravity.

Question 8

__________ is the only rock-forming silicate mineral that does not weather to clay.

A) Feldspar
B) Quartz
C) Biotite
D) Muscovite

Question 9

Decomposition and disintegration of rocks and minerals at the surface by mechanical and chemical processes is __________.

Question 10

__________ __________ reduces solid rock to small fragments but does not alter the chemical composition of rocks and minerals.

Question 11

Frost wedging is an example of __________ weathering.

Question 12

The process whereby granite fractures in large plates or shells like the layers of an onion is called __________.

Question 13

Feldspar weathers to form clay by the process of __________.

A) dissolution
B) hydrolysis
C) frost wedging
D) salt cracking

Question 14

The combined O and A soil horizons are also called __________.

Question 15

__________ is a hard crust on the soil that forms when calcium carbonate precipitates in soil.

Question 16

A __________ occurs when a block of material slides downhill as a consolidated unit over a gently curved fracture.

Question 17

Alteration of the composition of rocks and minerals by the interaction of air and water at the Earth's surface is __________ __________.

Question 18

A __________ accumulates beneath many cliffs as the result of frost wedging.

A) litter
B) topsoil
C) caliche
D) talus

Question 19

Wind, flowing water, glaciers, and gravity are agents of __________.

A) convection
B) isostasy
C) erosion
D) orogeny

Question 20

A flowing mixture of clay, silt, sand, and rock in which more than half of the particles are larger than sand is called a/an __________ __________.

Question 21

The least soluble major mineral in granite is:

A) calcite.
B) feldspar.
C) quartz.
D) mica.

Question 22

A mixture of sand, clay, silt, and generous amounts of organic matter is called __________.

A) soil
B) bedrock
C) humus
D) litter

Question 23

Granite commonly fractures by __________.

A) salt cracking
B) exfoliation
C) chemical weathering
D) none of these

Question 24

During a __________, a coherent block of material fractures and moves downslope.

A) slide
B) fall
C) flow
D) slump

Question 25

As feldspar weathers to clay, water reacts with the feldspar in a process called:

A) exfoliation.
B) oxidation.
C) hydrolysis.
D) dissolution.

Question 26

In the process of hydrolysis:

A) salts crystallize in cracks, enlarging fractures.
B) minerals weather by incorporating water.
C) bedrock expands and fractures when the overlying rock erodes away.
D) bedrock dissolves and ground water carries the dissolved ions away.

Question 27

The soil layer in which you would find the least organic material is the:

A) B horizon.
B) O horizon.
C) C horizon.
D) A horizon.

Question 28

A type of mass wasting in which a segment of bedrock slides downslope along a fracture is called __________.

A) creep
B) debris flow
C) rockslide
D) fall
Multiple Choice

Question 29

Soil on a hillside is generally __________ and __________ than on the valley floor.

A) thinner, poorer
B) deeper, richer
C) younger, richer
D) deeper, poorer

Question 30

The __________ is the maximum slope or steepness at which loose material remains stable.

A) dip slope
B) mass wasting angle
C) angle of repose
D) slip slope

Question 31

Mechanical weathering:

A) reduces solid rock to small fragments by altering the chemical composition of rocks and minerals.
B) reduces solid rock to small fragments without altering the chemical composition of rocks and minerals.
C) causes iron to rust.
D) picks up and carries off weathered rocks and minerals.

Question 32

Soil is usually only a __________ thick or less in most parts of the world.

A) hundred meters
B) few kilometers
C) few centimeters
D) few meters

Question 33

The soil layer in which you would find the most organic material is the __________ horizon.

A) B
B) O
C) C
D) A

Question 34

Weathering is the decomposition and disintegration of rocks and minerals at the Earth's surface by:

A) both mechanical and chemical processes.
B) chemical processes only.
C) mechanical processes only.
D) internal processes.

Question 35

__________ is a layer of loose rock fragments overlying bedrock.

A) Loam
B) Humus
C) Litter
D) Regolith

Question 36

In the weathering process of pressure-release fracturing:

A) salts crystallize in cracks, enlarging fractures.
B) bedrock minerals decompose to clay.
C) bedrock expands and fractures when the overlying rock erodes away.
D) bedrock dissolves and ground water carries the dissolved ions away.

Question 37

Rust is an example of __________.

A) dissolution
B) hydrolysis
C) frost wedging
D) oxidation

Question 38

Piles of talus found at the base of cliffs in high alpine areas are likely the result of:

A) chemical weathering.
B) pressure-relief fracturing.
C) abrasion.
D) frost wedging.

Question 39

Atmospheric carbon dioxide dissolves in rainwater and reacts to form a:

A) strong acid.
B) weak base.
C) weak acid.
D) strong base.

Question 40

Soil is a mixture of:

A) mineral grains, organic matter, gas, and oil.
B) gold, organic matter, gas, and water.
C) mineral grains, organic matter, oil, and water.
D) mineral grains, organic matter, gas, and water.

Question 41

Acidic and basic solutions have greater abilities to dissolve rocks and minerals than does pure water.

Question 42

Weathering is the decomposition and disintegration of rocks and minerals at the Earth's surface.

Question 43

In soils, leached ions and clay frequently accumulate in the:

A) B horizon.
B) O horizon.
C) A horizon.
D) C horizon.

Question 44

Rainwater is usually strongly acidic.

Question 45

The alternate shrinking and swelling of humus tightens soil and prevents roots from growing easily.

Question 46

Typically, soil creep occurs at a rate of about:

A) 1 centimeter per day.
B) 1 meter per year.
C) 1 centimeter per year.
D) 1 kilometer per year.

Question 47

Vegetation has a great influence on the probability of landslides.

Question 48

Sand can maintain an angle of repose up to 45°.

Question 49

Volcanic activity may initiate slides by melting snow and ice near the tops of volcanoes.

Question 50

Hydrolysis is an example of chemical weathering.

Question 51

Oxidation in rocks occurs when iron in minerals reacts with oxygen.

Question 52

During hydrolysis, water reacts with feldspar to form clay.

Question 53

You can distinguish creep from slump by the presence of pistol-butt trees.

Question 54

A defense against mass-wasting damage on a hillside is to:

A) clear away all the trees and shrubs on upper parts of the hill.
B) saturate the slope with water.
C) bulldoze away lower parts of the slope.
D) study an area's geology to determine if landslides have occurred on similar nearby slopes.
True/False

Question 55

During a rockslide (or rock avalanche), bedrock slides downslope over a fracture plane.

Question 56

Erosion involves little or no movement of the decomposed rocks and minerals.

Question 57

The type of mass wasting known as mudflow occurs when:

A) fine grained particles flow downslope.
B) rocks fall from cliffs.
C) water-saturated soil slides over permafrost.
D) blocks of material slide downhill over curved fractures.

Question 58

Mechanical weathering occurs when air and water react with rock to alter its chemical composition and mineral content.

Question 59

Trees on a hill affected by slump:

A) don't show any changes.
B) grown much faster.
C) tilt uphill.
D) tilt downhill.

Question 60

Fall is the most rapid type of mass wasting.