Exam 15: The Work of Wind and Deserts

Briefly explain why sand is moved by wind before clay and silt during wind erosion.

What is an isolated mountain that rises from the flat plain of a desert called?

Explain the ways in which alluvial fans and deltas are similar.

Although loess may originate in deserts,it is not deposited in them.

The size of material that is frequently carried as suspended load by wind is ____________________ and ____________________.

Air flows from ____________________ pressure regions to ____________________ pressure regions.

Loess

Deserts receive less than ______ centimeters of rain per year,on average.

How does the topography of the water table in deserts with through-flowing streams result in the restriction of much of the vegetation to the stream banks?

How is rock/desert varnish produced?

Sand covers approximately 75 percent of the world's deserts.

A broad alluvial apron formed by the coalescence of alluvial fans is called a(n)____.

How much land area is converted to deserts globally each year?

Briefly explain how the geological conditions that produced and deposited loess have determined the sites of the world's major grain belts.

The most effective agent of erosion in the deserts is ____________________.

Why are large alluvial fan deposits of importance to human residents of deserts?

What are deflation hollows?

The water table in deserts with through-flowing streams slopes toward the streams.

Alluvial fans are composed of sediment that is ______-sorted and ____________________ stratified.

Briefly explain how mesas and buttes form.