Deck 17: Cenozoic Earth History the Quaternary Period

Question 1

Mountain valleys that are U-shaped are most likely the result of erosion by a valley glacier.

Answer 1

True

Question 2

During the Pleistocene, Earth's temperature was relatively static although it was cooler than today.

Answer 2

False

Question 3

According to the Milankovitch theory, the amount of heat received by Earth greatly varies and glaciation occurs when solar input is at a low.

Answer 3

False

Question 4

During the Pleistocene glaciation, temperatures fluctuated by as much as 10^o C.

Question 5

Interglacial periods are commonly periods of regression.

Question 6

The higher abundance of O¹⁶ in glacial ice occurs because it is the lighter oxygen isotope; it evaporates more easily than O¹⁸ and then is precipitated as snow.

Question 7

The Earth is presently experiencing a glacial period.

Question 8

Most Pleistocene mineral deposits are directly or indirectly related to glaciation.

Question 9

The Milankovitch theory explains the onset of glacial epochs as a result of major plate tectonic activity.

Question 10

Areas of Scandinavia are rising as a result of isostatic rebound.

Question 11

Evaporite deposits such as borates formed as a result of the drying up of large pluvial lakes in the western United States.

Question 12

A geologist can recognize deposits made directly by a glacier, because the deposits tend to be poorly sorted with angular sediments.

Question 13

Increased glaciation is commonly associated with higher sea levels.

Question 14

Prior to the Ice Age, the Great Lakes were nonexistent.

Question 15

Pollen analysis is a useful tool to describe how climate and vegetation types have changed in a region.

Question 16

Although the last major ice sheets receded 10,000 years ago, pollen and tree ring data exist to indicate that since 6,000 years ago, there have been small glacial advances and retreats.

Question 17

One of the effects of the disappearance of pluvial lakes was the formation of thick sequences of evaporites.

Question 18

Increased volcanic activity may raise the temperature of Earth enough to make the climate warmer and more tropical.

Question 19

Plate tectonic activity is an important factor in global climate change because atmospheric and oceanic circulation patterns may be greatly affected by the location of landmasses.

Question 20

According to the Milankovitch theory, the total heat received from the sun varies very little, but there is enough interaction of orbit and tilt changes to cause climate changes.

Question 21

The person who contributed the most to the understanding and final acceptance of the theory of glaciation was ____.

A) Hutton
B) Agassiz
C) Smith
D) Lyell
E) Darwin

Question 22

The increased elevation of some areas of Scandinavia is the result of ____.

A) outwash
B) glacial rebound
C) the Milankovitch Theory
D) the Little Ice Age
E) varve development

Question 23

Any lake that formed in nonglaciated areas during the Pleistocene, as a result of increased precipitation and reduced evaporation rates during that time, is a(n) ____.

A) moraine
B) isostatic lake
C) proglacial lake
D) cirque
E) pluvial lake

Question 24

On which landmass does a continental glacier exist?

A) Europe
B) North America
C) South America
D) Greenland
E) Eurasia

Question 25

At their maximum extent, how much land did glaciers cover?

A) 10%
B) 20%
C) 30%
D) 50%
E) 75%

Question 26

A glacier covering at least 50,000 km² and unconfined by topography is classified as a(n) ____.

A) ice cap
B) continental glacier
C) moraine
D) cirque
E) valley glacier

Question 27

All sediment deposited by streams that issue from glaciers is called ____.

A) outwash
B) pluvial lake
C) varve
D) moraine
E) cirque

Question 28

In addition to being colder, glacial climates tend to be rather humid and moist.

Question 29

Several species of planktonic foraminifera are sensitive to climate change.

Question 30

Which method of movement is most important to glaciers?

A) glacial retreat
B) plastic flow
C) isostatic rebound
D) incremental advancement
E) creep

Question 31

The melting of continental glaciers will not affect sea level.

Question 32

Glaciers form where ____.

A) temperatures never dip below 32 degrees Celsius
B) temperatures never rise above 0 degrees Celsius
C) melting does not occur in the summer
D) melting does not occur in any season
E) snowfall in the winter exceeds melting in the summer

Question 33

The periods between glaciations are separated by warmer ____ stages.

A) endothermic
B) intercyclic
C) interglacial
D) thermostatic
E) intermontaine

Question 34

What concept describes Earth's crust as "floating" on denser underlying mantle?

A) outwash
B) accretion
C) isostasy
D) cyclothem
E) interglacial stage

Question 35

A glacier is retreating when ____.

A) accumulation exceeds ablation
B) snow changes into firn
C) accumulation and ablation are equal
D) ablation exceeds accumulation
E) basal slip exceeds plastic flow

Question 36

The zone of a glacier in which additions of ice exceed losses is called ____.

A) the zone of ablation
B) the zone of accumulation
C) the zone of wastage
D) the snowline
E) isostatic rebound

Question 37

Thick bars of gravel and large boulders provide evidence for massive flooding cause by the failure of large pluvial and proglacial lakes.

Question 38

The two most recent epochs of the Neogene Period, from oldest to youngest, are the ____.

A) Pleistocene and Pliocene
B) Holocene and Pleistocene
C) Holocene and Pliocene
D) Pleistocene and Holocene
E) Holocene and Paleocene

Question 39

How does glaciation affect volcanism?

A) Volcanoes become less active during glacial times, because temperatures are cooler.
B) Volcanoes become less active during glacial times, because they are covered with ice.
C) Volcanism and glaciation have not been shown to have a causal relationship to each other.
D) Volcanoes become more active as heat is trapped in Earth.
E) Volcanoes become more active in order to end the glaciation.

Question 40

Volcanoes in the Cascade Range and Yellowstone have remained active during the Pleistocene glaciations.

Question 41

During the Wisconsinan, Death Valley contained a(n) ____________________.

Question 42

A dome-shaped mass of glacial ice covering less than 50,000 km² is a(n) ____________________ ____________________.

Question 43

During a glacial period, ice contains ____ than seawater, while seawater has ____ than ice.

A) less oxygen 16; more oxygen 16
B) more oxygen 16; more oxygen 18
C) less oxygen 16; less oxygen 18
D) more oxygen 18; less oxygen 18
E) more oxygen 18, more oxygen 16

Question 44

Parts of Scandinavia are presently increasing in elevation because of ____________________.

Question 45

Dark-light couplets of sedimentary laminations representing an annual deposit in a glacial lake are ____________________.

Question 46

Any lake formed of meltwater accumulating along the margin of a glacier is classified as a(n) ____________________ lake

Question 47

Isotopes of the element ____________________ are used to reconstruct past glacial and interglacial stages.

Question 48

____________________ glaciers produced bowl-shaped depressions on mountains called cirques.

Question 49

Salt deposits from glacial times formed via ____.

A) advancing sea levels
B) retreating sea levels
C) evaporation of pluvial lakes
D) deposition of carbonates in pluvial lakes
E) deposition of carbonates in proglacial lakes

Question 50

Planktonic foraminifera provide evidence for glaciation based on ____.

A) shell size
B) shell striations
C) carbon isotope ratios
D) coiling direction
E) number of offspring

Question 51

____ moraines allow geologists to determine the farthermost advance of Pleistocene glaciers.

A) Lateral
B) Recessional
C) Medial
D) Terminal
E) Finial

Question 52

During a glacial period, sea level would be expected to be ____.

A) higher than average, because more ice is in the water
B) lower than average, because sea water has been used to make ice
C) unaffected by changes in sea water and ice
D) higher than average, because land surfaces are subsiding
E) higher at the poles, but lower at the equator

Question 53

Global warming is causing most glaciers to ____.

A) advance
B) retreat
C) surge
D) stabilize
E) have positive budgets

Question 54

It is predicted that as carbon dioxide levels rise, Earth will ____.

A) become more sensitive to Milankovitch cycles
B) experience an increase in the rate of plate movement
C) likely experience more glacial periods
D) become cooler
E) become warmer

Question 55

A glacier forms when ____.

A) snow moves downslope under the influence of gravity
B) ice is present year-round at a mountain top
C) temperatures stay below freezing year-round
D) ice reaches a thickness of 10 meters
E) an ice mass begins to flow under its own weight

Question 56

The scablands of Washington and large ripple marks in Montana and Idaho were formed when the ____.

A) proglacial Lake Missoula flooded
B) pluvial Lake Missoula flooded
C) proglacial Lake Bonneville flooded
D) pluvial Lake Bonneville flooded
E) Wisconsinan glacier experienced a catastrophic failure

Question 57

The glaciers in Glacier National Park are examples of ____________________ glaciers.

Question 58

____________________are ridges or mounds of unsorted, unstratified debris deposited by a glacier along its margins or at its terminus.

Question 59

A steep-walled, bowl-shaped depression formed on a mountainside by glacial erosion is called a(n) ____________________.

Question 60

Short-term climatic changes may be caused by ____.

A) orbital eccentricity
B) axial tilt
C) precession of the equinoxes
D) volcanic activity
E) a combination of orbital eccentricity and axial tilt

Question 61

Discuss three lines of evidence that provide paleoclimatic data showing when glaciations started and ended.

Question 62

Explain the concept of isostatic rebound, and cite evidence for rebound that has occurred since the end of the Pleistocene.

Question 63

Discuss the concept of isostasy. Provide evidence that it occurs and examples of its effects.

Question 64

Compare and contrast pluvial and proglacial lakes.

Question 65

How did continental glaciations affect areas far away from ice sheets? What were some of these effects?

Question 66

Discuss the causes of large-scale glaciation and the controls on ice advances and retreats within ice ages.

Question 67

Describe the Little Ice Age. What geographic areas were affected, and what consequences did the Little Ice Age have on them?

Question 68

Explain the Milankovitch Theory.

Question 69

What is the "precession of the equinoxes," and how does it affect glaciation?

Question 70

Compare and contrast erosional and depositional glacial landforms. How do they form? Provide examples.