Physical Geology Learning Objectives and Study Questions
Chapter 16: Tarbuck and Lutgens, 12th ed.
1. Use data on a region's long-term evapotranspiration and precipitation to infer whether or not it is a
desert.
2. Briefly explain how the processes that create subtropical deserts are similar to and different from
those which create rainshadow deserts.
3. Identify several common desert landforms that are formed primarily by water (arroyos, alluvial fans,
bajadas, playas, inselbergs) on a map or relief model.
4. Briefly contrast desert pavement, blowouts, yardangs, and ventrifacts in terms of the wind-driven
erosional processes that produce them.
5. Determine the direction of the prevailing wind in a desert region based on the orientation of barchan
dunes shown on a map, photograph, or relief model.
6. Briefly contrast sand dunes and loess in terms of the types of sediment load they represent for wind.
1. Deserts are characterized by arid climates in which, over the long-term, evapotranspiration _____
precipitation.
A. correlates perfectly with
B. exactly equals
C. happens more slowly than
D. is greater than
E. is less than
2. Subtropical or “planetary wind system” deserts are located _____.
A. far inland
B. leeward of mountains
C. near the poles
D. near cold ocean currents
E. 20°-30° N and S
3. As streams exit the mouths of desert canyons their capacities drop due to lower gradients and
infiltration, causing them to build _____.
A. alluvial fans
B. playas
C. pediments
D. inselbergs
E. arroyos
4. In arid regions, ephemeral lakes that form in closed basins—as well as the dry beds left behind when
they evaporate—are known as _____.
A. floodplains
B. sinks
C. sumps
D. oases
E. playas
5. Winds erode landscapes by a combination of abrasion and _____.
A. corrosion
B. deflation
C. plucking
D. quarrying
E. suspension
6. Traditionally, we think of desert pavement as being produced in arid regions by the process of
_____.
A. abrasion
B. corrosion
C. deflation
D. dispersion
E. plucking
7. The wind that produced the dunes shown at right was
blowing _____.
A. away from us
B. from the left
C. from the right
D. towards us
E. indeterminate, we cannot tell
8. Deposits of wind-blown silt (especially from ancient glacial
deposits) are called _____.
A. blowouts
B. desert pavement
C. dunes
D. loess
E. playas