Chapter 18 Glaciers and Glaciation
Earth: An Introduction to Physical Geology, 9e (Tarbuck/Lutgens)
18.1 Multiple-Choice Questions
1) The ________ is not the name of a Pleistocene glacial episode in North America.
A) Dakotan
B) Kansan
C) Illinoian
D) Nebraskan
Answer: A
Diff: 1
2) The ________ was the most recent Pleistocene glacial episode in North America.
A) Dakotan
B) Kansan
C) Indianan
D) Wisconsinan
Answer: D
Diff: 1
3) ________ is one of the two, major flow mechanism in a glacier.
A) Basal slip
B) Crevassal slip
C) Frost heaving
D) Morainal sliding
Answer: A
Diff: 1
4) Where is the world's largest ice sheet located today?
A) Greenland
B) Russia, Siberia
C) Iceland
D) Antarctica
Answer: D
Diff: 1
5) Approximately how long ago did the last of the great North American ice sheets melt?
A) 1500 yrs
B) 1.5 million yrs
C) 15,000 yrs
D) 150,000 yrs
Answer: C
Diff: 1
1
6) ________ has/have speeds comparable to those of a flowing alpine glacier.
A) Soil creep
B) Streams
C) Mudflows
D) Basaltic lava flows
Answer: A
Diff: 1
7) The bottom or downward tip of a crevasse marks the ________.
A) boundary between parts of the glacier moving by basal sliding and crevassal slip
B) boundary between the basal sliding and external flowage zones
C) bottom of the basal sliding zone
D) top of the internal deformation and flowage zone
Answer: D
Diff: 1
8) Which one of the following applies to a valley glacier that lengthens (extends its terminus
downslope) over a period of many years?
A) Wastage exceeds accumulation.
B) Accumulation exceeds wastage.
C) Accumulation and wastage are about equal.
D) none of the above
Answer: B
Diff: 1
9) Abrasion and plucking generally involve what part of a glacier?
A) the internal, flowage zone
B) the snout zone
C) the surface, brittle zone
D) the basal, sliding zone
Answer: D
Diff: 1
10) A ________ cross-valley profile is typical of canyons and valleys eroded and deepened by
alpine or valley glaciers.
A) U
B) Y
C) V
D) S
Answer: A
Diff: 1
11) ________ are erosional features produced by valley/alpine glaciers.
A) Moraines
B) Cirques
C) Eskers
D) Drumlins
Answer: B
Diff: 1
2
12) A(n) ________ is a depositional feature composed of till and only associated with continental
glaciation, not with alpine glaciers.
A) till
B) outwash
C) solid rock
D) outwash deposit
Answer: C
Diff: 1
Match the feature with the appropriate material.
A. till
B. outwash
C. solid rock
13) ________ moraine
Answer: A
Diff: 1
14) ________ erratic
Answer: C
Diff: 1
15) ________ cirque
Answer: C
Diff: 1
16) ________ esker
Answer: B
Diff: 1
17) ________ horn
Answer: C
Diff: 1
18) ________ drumlin
Answer: A
Diff: 1
19) ________ first developed the theory that small variations in the Earth-Sun distance were
responsible for short term, climatic oscillations (1000 to 100,000 years).
A) H. Goering
B) H. Marcee
C) G. Zukhov
D) M. Milankovitch
Answer: D
Diff: 1
3
20) The great, Southern Hemisphere glaciation that affected parts of Africa, South America,
India, Australia, and Antarctica occurred ________.
A) in late Paleozoic time
B) in late Proterozoic time
C) in early Cenozoic time
D) in middle Mesozoic time
Answer: A
Diff: 1
21) Which of the following glacial features would typically be found in close proximity?
A) cirque and terminal moraine
B) outwash plain and horn
C) hanging valley and truncated spur
D) drumlin and fiord
Answer: C
Diff: 1
22) A(n) ________ represents a former meltwater channel or tunnel in glacial ice that was filled
with sand and gravel.
A) esker
B) yazoo ridge
C) valley plain
D) kettle
Answer: A
Diff: 1
23) What type of moraine would be most useful for tracing diamond-bearing kimberlite
fragments directly to their bedrock source area?
A) terminal, valley or alpine glacier
B) terminal, continental ice sheet
C) recessional, continental ice sheet
D) lateral, valley or alpine glacier
Answer: D
Diff: 1
24) Which one of the following samples and experimental measurements would provide the
most information about the Earth's climate over the last 100,000 years or so?
A) cores from sea ice in the Arctic Ocean; NaCl content
B) sediment cores from a terminal moraine in Ohio; sand-to-clay ratio
C) sediment cores from a Pleistocene loess deposit in the state of Mississippi; Si
content
D) cores from the Greenland ice sheet; ratios of the oxygen isotopes (0-18/0-16)
Answer: D
Diff: 1
4
25) ________ is the best explanation for a glacial surge.
A) The climate cools suddenly and a retreating glacier begins to advance
B) Heavy snowfalls resulting in avalanches in the zone of accumulation
C) Melting at the base of the glacier resulting in increased rates of basal slip
D) Crevasses opening suddenly near the snout of a glacier
Answer: C
Diff: 1
26) All of the following descriptions apply to stratified drift (not glacial till) except for ________.
A) deposited directly from melting ice
B) sand and gravel beds
C) deposits are often layered and well-sorted
D) deposited by glacial meltwater streams
Answer: B
Diff: 1
27) A(n) ________ is similar in appearance to a sinkhole of a karst area.
A) moraine
B) esker
C) cirque
D) kettle
Answer: D
Diff: 1
28) Which one of the following prominent landforms, located from the Wasatch Range, UT,
westward to the Sierra Nevada, CA, formed during the Pleistocene glacial episodes?
A) terminal moraines of continental ice sheets that moved south from Canada
B) old shorelines of large, pluvial lakes
C) erosional features produced by continental glaciation
D) subaerial deltas submerged by the post-glacial rise in sea level
Answer: B
Diff: 1
29) A fiord is ________.
A) a stream valley, deepened by glacial erosion, that floods as sea level rises
B) a glacier-cut valley that is dammed by an end moraine and a large lake is formed
C) a glacier-cut valley which sinks below sea level due to glacial rebound after the ice
melts
D) a large, kettle-pocked moraine left as an island when sea level rises following melting
of the ice
Answer: A
Diff: 1
5
30) Which process occurs where a glacier enters the sea?
A) kaming
B) calving
C) surging
D) drowning
Answer: B
Diff: 1
31) The ________ of the geologic time scale represents the time of the most recent "Ice Age."
A) Pleistocene era
B) Pliocene epoch
C) Pleistocene epoch
D) Pliocene era
Answer: C
Diff: 1
32) Which of the following is the correct listing of the North American glacial stages from older
to younger?
A) Indianan, Kansan, Nebraskan, Ohioan
B) Kansan, Illinoian, Iowan, Dakotan
C) Nebraskan, Indianan, Illinoian, Wisconsinan
D) Nebraskan, Kansan, Illinoian, Wisconsinan
Answer: D
Diff: 1
33) Which one of the following statements concerning glaciers is not true?
A) Ice sheets are larger than ice caps.
B) Piedmont glaciers form on lowlands at the base of mountainous terrain.
C) The volume of water tied up in the Antarctic ice sheet is about the same as the total
discharge of the Amazon River in one year.
D) Long, extended, alpine glaciers occupied valleys in most high, mountainous areas in
the United States, Canada, and Europe at one or more times during the past two
million years.
Answer: D
Diff: 1
34) A ________ is an erosional feature specifically produced by alpine glaciation.
A) lateral moraine
B) drumlin
C) crevasse spur
D) U-shaped valley
Answer: D
Diff: 1
6
35) A(n) ________ is likely to host a waterfall or steep rapids today.
A) outwash plain
B) hanging valley
C) striated drumlin
D) horn peak
Answer: B
Diff: 1
36) A ________ is a glacier-cut valley that partly flooded as sea level rose.
A) till crevasse
B) fiord
C) hanging cirque
D) kettle trough
Answer: B
Diff: 1
37) A drumlin is a ________.
A) smooth, tapering ridge of till; formed and shaped beneath a continental ice sheet
B) bowl-shaped depression eroded largely by frost action and glacial plucking
C) till mound of outwash deposited by meltwater streams at the snout of a glacier
D) smooth, striated, bedrock ridge shaped and polished by a glacier
Answer: A
Diff: 1
38) ________ are both deposited by meltwater streams.
A) Terminal moraines and cirques
B) Outwash plains and valley trains
C) Valley moraines and ice sheet trains
D) Recessional kettles and erratics
Answer: B
Diff: 1
39) Where is the world's second largest continental ice sheet?
A) Iceland
B) Greenland
C) Antarctica
D) Siberian Russia
Answer: B
Diff: 1
40) How do icebergs in the North Atlantic Ocean originate?
A) by calving of large piedmont glaciers in Greenland
B) as large masses of sea ice that float northward from Antarctica
C) as masses of sea ice that float southward from the Arctic Ocean
D) as calved blocks of glacial ice that float northward from Antarctica
Answer: A
Diff: 1
7
41) Which of the following best describes the term glacial drift?
A) floating of icebergs southward from the north polar seas
B) slow, plastic flow movement in the brittle zone of a glacier
C) the sedimentary materials outwash and till
D) the slow, southward advance of the continental ice sheets over Canada and North
America during the Pleistocene
Answer: C
Diff: 1
42) Which one of the following statements concerning glacial deposits is not true?
A) Till is deposited directly from the ice; outwash is deposited by meltwater streams.
B) Glacial erratics are blocks of rock that are too large for the glacier to move.
C) Tills are poorly sorted and the fragments are mostly angular.
D) Outwash is mainly stratified sand and gravel.
Answer: B
Diff: 1
43) What type of moraine is formed by the merging of two lateral moraines at a junction of two
valley glaciers?
A) medial
B) recessional
C) ground
D) kettle
Answer: A
Diff: 1
44) A ________ forms when stagnant, glacial ice melts after being buried by drift.
A) tarn
B) kettle
C) drumlin
D) pluvial delta
Answer: B
Diff: 1
45) Which one of the following could not have significantly affected climatic variations and
advances and retreats of ice sheets during the Pleistocene epoch?
A) movements of Earth's tectonic plates
B) variations in the Sun's energy output
C) precession of Earth's orbit
D) wobbling of Earth's rotational axis
Answer: A
Diff: 1
8
46) ________ was a very large, pluvial lake in Utah during the Pleistocene Epoch.
A) Lake Caspian
B) Lake Aral
C) Lake Mead
D) Lake Bonneville
Answer: D
Diff: 1
47) A ________ would logically be situated next to a large end moraine or terminal moraine.
A) cirque
B) fiord
C) pluvial lake
D) outwash plain
Answer: D
Diff: 1
48) Which of the following is often associated with a cirque basin in high, mountainous terrain?
A) loon lake
B) kettle pond
C) tarn lake
D) arête pond
Answer: C
Diff: 1
49) ________ is an irregular, usually thin till layer laid down by a retreating glacier.
A) Terminal moraine
B) Outwash blanket
C) Kame sheet
D) Ground moraine
Answer: D
Diff: 1
50) All of the following are thought to possibly contribute to the formation of glaciers except for
________.
A) eccentricity
B) precession
C) comets
D) plate tectonics
Answer: C
Diff: 1
9
18.2 Word Analysis Questions
Examine the words and/or phrases for each question below and determine the relationship among the
majority of words/phrases. Choose the option which does not fit the pattern.
1) A) drumlin
B) cirque
C) esker
D) moraine
Answer: cirque
Diff: 1
2) A) horn
Answer: drumlin
B) arête
C) lateral moraine
D) drumlin
C) melting
D) zone of wastage
Diff: 1
3) A) calving
B) zone of accumulation
Answer: zone of accumulation
Diff: 1
4) A) truncated spur
B) glacial trough
lake
Answer: pater noster lake
C) hanging valley D) pater noster
Diff: 2
5) A) drumlin
Answer: drumlin
B) kame
C) kettle
D) esker
Diff: 2
18.3 True/False Questions
1) When a glacier is retreating, the upstream ice is still moving forward toward the
downstream terminus of the glacier.
Answer: TRUE
Diff: 1
2) Crevasses are short, narrow cracks in the plastic flow zone of a glacier that alternately open
and close as the ice flows along.
Answer: FALSE
Diff: 1
3) The downstream end or snout of a glacier advances over periods of time during which
ablation exceeds accumulation.
Answer: FALSE
Diff: 1
4) Till is an unsorted sediment deposited directly from the melting glacial ice; stream action is
not involved.
Answer: TRUE
Diff: 1
10
5) The recessional moraine is the largest of many terminal moraines laid down by a retreating
glacier.
Answer: FALSE
Diff: 1
6) Melting and evaporation are two forms of ablative calving.
Answer: FALSE
Diff: 1
7) Fiords are glacier-cut valleys that flooded as sea level rose in post-glacial times.
Answer: TRUE
Diff: 1
8) A cirque represents an erosional feature formed in what was an important accumulation
zone for snow and ice at the upstream head of a glacier.
Answer: TRUE
Diff: 1
9) The volume of the Antarctic ice sheet is about equal to the total volume of ice in all alpine
glaciers of the world.
Answer: FALSE
Diff: 1
10) The Pleistocene epoch of geological time began about 6 million years ago.
Answer: FALSE
Diff: 1
11) Because ice floats on seawater, coastal piedmont glaciers seldom erode much below the
elevation of sea level at the times the glaciers are active.
Answer: TRUE
Diff: 1
12) The great, Southern Hemisphere glaciation left Jurassic tills on parts of South America,
India, and South Africa.
Answer: FALSE
Diff: 1
13) Rapid surge movements of the Earth's tectonic plates offer a convincing explanation for the
advances and retreats of the Pleistocene ice sheets.
Answer: FALSE
Diff: 1
14) Great Salt Lake in Utah is the shrunken, salty remnant of a much larger, Pleistocene, pluvial
lake called Lake Bonneville.
Answer: TRUE
Diff: 1
15) Arête, horns, and U-shaped valleys are erosional features carved from bedrock by glaciers.
Answer: TRUE
Diff: 1
11
16) Sand and gravel deposited by glacial meltwater streams are known as outwash till or
stratified till.
Answer: FALSE
Diff: 1
17) In the north-central United States, much of the land north of the Ohio and Missouri Rivers
was covered by one or more of the Pleistocene ice sheets.
Answer: TRUE
Diff: 1
18) Surges in glacial movement are probably related to unusually fast rates of basal sliding.
Answer: TRUE
Diff: 1
19) Rock flour consists of silt-sized, rock and mineral particles produced by glacial abrasion.
Answer: TRUE
Diff: 1
20) Eskers and kames are deposited by meltwater streams; they are composed of stratified sand
and gravel.
Answer: TRUE
Diff: 1
21) Drumlins are believed to represent deltas built into pluvial lakes by meltwater streams.
Answer: FALSE
Diff: 1
22) Eccentricity, obliquity, and precession are three factors involved in the Milankovitch
astronomical explanation of why the Pleistocene continental ice sheets alternately grew and
shrank in size.
Answer: TRUE
Diff: 1
18.4 Short Answer Questions
1) The upper 40 meters or so of a glacier is known as the zone of ________.
Answer: fracture
Diff: 1
2) Unusually rapid, forward movements of glaciers are called ________.
Answer: surges
Diff: 1
3) List the two, major mechanisms of glacial flow.
Answer: plastic flow; basal slip
Diff: 1
4) What term describes open fissures in the brittle, surface ice of a glacier?
Answer: crevasse
Diff: 1
12
5) What general term denotes wastage of a glacier?
Answer: ablation
Diff: 1
6) Bridal Veil Falls in Yosemite National Park is an example of a ________.
Answer: hanging valley
Diff: 1
7) Bowl-shaped depressions in bedrock at upstream ends of alpine glacial valleys are called
________.
Answer: cirque
Diff: 1
8) The wobbling motion of a spinning object is known as ________.
Answer: precession
Diff: 1
9) During the Pleistocene glacial epoch, pluvial lakes were common in valley regions of what
part of the United States?
Answer: Basin & Range
Diff: 1
10) What is the name for the very large, pluvial lake that once existed in northwestern Utah?
Answer: Lake Bonneville
Diff: 1
11) ________ are smoothly tapered, elongated hills of till shaped by an overriding, continental
ice sheet.
Answer: Drumlins
Diff: 1
12) What is the oldest, Pleistocene, glacial stage in North America?
Answer: Nebraskan
Diff: 1
13) A(n) ________ is a closed depression formed by melting of an ice block buried in a moraine
or outwash plain.
Answer: kettle
Diff: 1
14) A(n) ________ is a narrow, winding ridge composed of outwash deposited in a tunnel or
channel cut into stagnant, glacial ice.
Answer: esker
Diff: 1
15) Valleys deeply eroded by alpine glaciers have what characteristic, cross-valley profile?
Answer: U-shaped
Diff: 1
13
16) What term denotes a glacial valley that was partly flooded as sea level rose?
Answer: fiord
Diff: 1
18.5 Critical Thinking Questions
Use complete sentences, correct spelling, and the information presented in Chapter 18 to answer the
questions below
1) Would most features of alpine glaciation be preserved in the geologic record? Why or why
not? What about continental glaciation?
Diff: 3
2) Glacial ice is very effective as an agent of erosion. How would you identify glacial sediments
from alluvial (stream) sediments? Also, could certain glacial sediments be mistaken for
alluvium?
Diff: 3
3) Briefly discuss the indirect effects of glaciation. Indicate whether such changes would occur
in conjunction with glaciation or at some time later?
Diff: 3
18.6 Visualization Questions
1) Label the zones of ice movement on the glacier in the diagram below.
Answer: See figure 18.8 in chapter 18 of Earth, 9e
Diff: 1
14
2) Label the zone of accumulation and the zone of wastage on the diagram below.
Answer: See figure 18.11 in chapter 18 of Earth, 9e
Diff: 1
3) On the blanks provided below, fill in the name of the labeled features that formed as a
product of alpine glaciation.
Answer: a) hanging valley b) arête c) horn d) tarn e) pater noster lake f) cirques
Diff: 2
15
4) Match the features on the illustration below to the correct answer for each one.
Answer: a) C b) E c) D d) A e) F f) B
Diff: 2
16