Question 1

Which statement about the differences between cold deserts and hot deserts is most accurate?

Accepted Answer

A)  Cold deserts are found only in polar regions, and hot deserts elsewhere. 
B)  Cold deserts are found in polar regions and some high-altitude regions outside the poles, and hot deserts are found only in continental interiors or the subtropics. 
C)  Cold deserts can have precipitation occur as snow, whereas any/all precipitation in hot deserts is rain (or occasionally hail). 
D)  Cold deserts rarely have air temperatures > 20°C, whereas hot deserts often have daytime temperatures > 35° C. 
A)  Cold deserts are found only in polar regions, and hot deserts elsewhere. 
B)  Cold deserts are found in polar regions and some high-altitude regions outside the poles, and hot deserts are found only in continental interiors or the subtropics. 
C)  Cold deserts can have precipitation occur as snow, whereas any/all precipitation in hot deserts is rain (or occasionally hail). 
D)  Cold deserts rarely have air temperatures > 20°C, whereas hot deserts often have daytime temperatures > 35° C.

Question 2

To qualify as a desert,a region must ____________.

Accepted Answer

A)  be hot, with a mean annual temperature greater than 25°C (77°F) 
B)  be arid, with less than 15% of the ground surface vegetated 
C)  have a mean annual temperature greater than 25°C and less than 5 cm annual rainfall 
D)  have no rainfall three out of four seasons 
A)  be hot, with a mean annual temperature greater than 25°C (77°F) 
B)  be arid, with less than 15% of the ground surface vegetated 
C)  have a mean annual temperature greater than 25°C and less than 5 cm annual rainfall 
D)  have no rainfall three out of four seasons

Question 3

The Gobi of Mongolia is a desert primarily because it is located ____________.

Accepted Answer

A)  in the subtropics 
B)  in a polar region 
C)  near the center of a large continent 
D)  next to a cold ocean current 
A)  in the subtropics 
B)  in a polar region 
C)  near the center of a large continent 
D)  next to a cold ocean current

Question 4

Desert areas constitute what percent of the Earth's surface?

Accepted Answer

A)  5% 
B)  15% 
C)  25% 
D)  40% 
A)  5% 
B)  15% 
C)  25% 
D)  40%

Question 5

Desert climate associated with a rain shadow is found ____________.

Accepted Answer

A)  on the windward side of mountain ranges 
B)  on the leeward side of mountain ranges 
C)  in the middle of flat plains 
D)  along continental coastlines 
A)  on the windward side of mountain ranges 
B)  on the leeward side of mountain ranges 
C)  in the middle of flat plains 
D)  along continental coastlines

Question 6

Which of these is NOT necessary for the formation of a bajada?

Accepted Answer

A)  clastic sediment 
B)  an arid environment 
C)  multiple canyon, stream, or other outlets along a mountain front 
D)  shallow groundwater rich in calcium and other ions 
A)  clastic sediment 
B)  an arid environment 
C)  multiple canyon, stream, or other outlets along a mountain front 
D)  shallow groundwater rich in calcium and other ions

Question 7

Which feature in the the photo below would a geologist study to infer that running water was the primary agent to have formed the landscape in the photo?

Accepted Answer

A)  the sand dunes 
B)  the dendritic patterns 
C)  the alluvial fans 
D)  the volcanoes 
A)  the sand dunes 
B)  the dendritic patterns 
C)  the alluvial fans 
D)  the volcanoes

Question 8

Mesas,buttes,and chimneys have which of these in common?

Accepted Answer

A)  They form only in hot deserts. 
B)  They form from basalt flow caps on softer rocks. 
C)  They form in flat-lying rocks. 
D)  They form only in subtropical deserts. 
A)  They form only in hot deserts. 
B)  They form from basalt flow caps on softer rocks. 
C)  They form in flat-lying rocks. 
D)  They form only in subtropical deserts.

Question 9

Cuestas can form when ____________.

Accepted Answer

A)  winds remove certain sizes of sediment from the land surface 
B)  water flows intermittently 
C)  beds or layers are dipping 
D)  the wind blows strongly from two different directions and there is an abundant supply of sand 
A)  winds remove certain sizes of sediment from the land surface 
B)  water flows intermittently 
C)  beds or layers are dipping 
D)  the wind blows strongly from two different directions and there is an abundant supply of sand

Question 10

The dominant process of clast transport in active sand dunes is ____________.

Accepted Answer

A)  saltation 
B)  sliding 
C)  deflation 
D)  suspension 
A)  saltation 
B)  sliding 
C)  deflation 
D)  suspension

Question 11

Two other names for desert washes (dry gullies)are ____________.

Accepted Answer

A)  barchans and wadis 
B)  wadis and arroyos 
C)  arroyos and inselbergs 
D)  inselbergs and wadis 
A)  barchans and wadis 
B)  wadis and arroyos 
C)  arroyos and inselbergs 
D)  inselbergs and wadis

Question 12

During heavy rainstorms,rates of physical weathering and erosion are ____________.

Accepted Answer

A)  greater in humid climates than in deserts because dry desert soils can soak up all of the available moisture 
B)  greater in deserts than in humid climates because soil tends to be more easily eroded in deserts than in humid regions 
C)  greater in humid climates than in deserts because vegetation tends to break up the soil 
D)  about equally fast in deserts and in humid climates 
A)  greater in humid climates than in deserts because dry desert soils can soak up all of the available moisture 
B)  greater in deserts than in humid climates because soil tends to be more easily eroded in deserts than in humid regions 
C)  greater in humid climates than in deserts because vegetation tends to break up the soil 
D)  about equally fast in deserts and in humid climates

Question 13

Which of the following is NOT necessary for the formation of calcrete?

Accepted Answer

A)  leaching of soluble mineral constituents by water 
B)  precipitation of soluble mineral constituents 
C)  the flow or wicking of water within the ground 
D)  warm or hot daytime temperatures 
A)  leaching of soluble mineral constituents by water 
B)  precipitation of soluble mineral constituents 
C)  the flow or wicking of water within the ground 
D)  warm or hot daytime temperatures

Question 14

Coastal region deserts are most likely near ocean currents that flow ____________.

Accepted Answer

A)  west 
B)  east 
C)  away from the equator toward one of the poles 
D)  away from one of the poles toward the equator 
A)  west 
B)  east 
C)  away from the equator toward one of the poles 
D)  away from one of the poles toward the equator

Question 15

If you excavated an exploratory trench from left to right through either of the sand dunes in the figure below,which way would you expect to find the cross-beds dipping?

Accepted Answer

A)  vertically 
B)  to the right 
C)  to the left 
D)  horizontally 
A)  vertically 
B)  to the right 
C)  to the left 
D)  horizontally

Question 16

"Desert pavement" results from ___________.

Accepted Answer

A)  deflation 
B)  saltation 
C)  evaporation 
D)  salt-wedging within cracks, joints, and fractures 
A)  deflation 
B)  saltation 
C)  evaporation 
D)  salt-wedging within cracks, joints, and fractures

Question 17

A newer theory about desert varnish suggests it does not form from chemical constituents of the rocks on which it is found.Which of the following statements about the newer theory of the formation of desert varnish is NOT true?

Accepted Answer

A)  Cosmic rays (which tend to be absorbed by moisture-rich air masses over nondesert areas) reach the desert surfaces in sufficient amounts to trigger an alteration process that forms desert varnish. 
B)  Bacteria are involved in the formation of desert varnish. 
C)  The presence of both dust and dew are necessary for the formation of desert varnish. 
D)  Rainfall disrupts the formation of desert varnish. 
A)  Cosmic rays (which tend to be absorbed by moisture-rich air masses over nondesert areas) reach the desert surfaces in sufficient amounts to trigger an alteration process that forms desert varnish. 
B)  Bacteria are involved in the formation of desert varnish. 
C)  The presence of both dust and dew are necessary for the formation of desert varnish. 
D)  Rainfall disrupts the formation of desert varnish.

Question 18

Because of little rainfall,the majority of physical weathering and transport of sediments in deserts is accomplished by the wind.

Accepted Answer

A) True 
 B)False

Question 19

A vast region of desert sand dunes is called a(n)_________.

Accepted Answer

A)  wadi 
B)  dune field 
C)  erg 
D)  loess region 
A)  wadi 
B)  dune field 
C)  erg 
D)  loess region

Question 20

Native Americans produced petroglyphs by etching into ____________.

Accepted Answer

A)  rocks that had been subjected to case hardening 
B)  rocks that had been coated with desert varnish 
C)  dark basalts 
D)  obsidian 
A)  rocks that had been subjected to case hardening 
B)  rocks that had been coated with desert varnish 
C)  dark basalts 
D)  obsidian

Exam 17: Dry Regions: the Geology of Deserts

Which statement about the differences between cold deserts and hot deserts is most accurate?

To qualify as a desert,a region must ____________.

The Gobi of Mongolia is a desert primarily because it is located ____________.

Desert areas constitute what percent of the Earth's surface?

Desert climate associated with a rain shadow is found ____________.

Which of these is NOT necessary for the formation of a bajada?

Which feature in the the photo below would a geologist study to infer that running water was the primary agent to have formed the landscape in the photo?

Mesas,buttes,and chimneys have which of these in common?

Cuestas can form when ____________.

The dominant process of clast transport in active sand dunes is ____________.

Two other names for desert washes (dry gullies)are ____________.

During heavy rainstorms,rates of physical weathering and erosion are ____________.

Which of the following is NOT necessary for the formation of calcrete?

Coastal region deserts are most likely near ocean currents that flow ____________.

If you excavated an exploratory trench from left to right through either of the sand dunes in the figure below,which way would you expect to find the cross-beds dipping?

"Desert pavement" results from ___________.

A newer theory about desert varnish suggests it does not form from chemical constituents of the rocks on which it is found.Which of the following statements about the newer theory of the formation of desert varnish is NOT true?

Because of little rainfall,the majority of physical weathering and transport of sediments in deserts is accomplished by the wind.

A vast region of desert sand dunes is called a(n)_________.

Native Americans produced petroglyphs by etching into ____________.

The Earth in Context

The Way the Earth Works: Plate Tectonics

Patterns in Nature: Minerals

Up From the Inferno: Magma and Igneous Rocks

The Wrath of Vulcan: Volcanic Eruptions

Pages of Earths Past: Sedimentary Rocks

Metamorphism: a Process of Change

A Violent Pulse: Earthquakes

Crags, cracks, and Crumples: Crustal Deformation and Mountain Building

Deep Time: How Old Is Old

A Biography of Earth

Riches in Rock: Energy and Mineral Resources

Unsafe Ground: Landslides and Other Mass Movements

Streams and Floods: the Geology of Running Water

Restless Realm: Oceans and Coasts

A Hidden Reserve: Groundwater

Amazing Ice: Glaciers and Ice Ages

Global Change in the Earth System

Rock Groups

A Surface Veneer: Sediments and Soils

The Rock Cycle

The Earths Interior Revisited: Insights From Geophysics

Memories of Past Life: Fossils and Evolution

An Introduction to Landscapes and the Hydrologic Cycle

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