Chapter 13 Flashcards
What is a desert?
Any region with low rainfall. Usually less than 25 centimeters of rain per year.
What is rain shadow?
When a mountain causes a dessert on one side and an owasses on the other.
What are monoclines?
Step like folds or bends in rock layers.
What is a playa lake?
A shallow temporary lake on a flat valley floor in a dry region.
What is a playa
A very flat surface underlain by hard, mud-cracked clay.
What is a bajada?
A broad, gently sloping, depositional surface formed at the base of a mountain range in a dry region by the coalescing of individual alluvial fans.
What is a pediment?
A gently sloping erosional surface cut into the solid rock of a mountain range in a dry region; usually covered with a thin veneer of gravel.
What is a ventifacts?
Rocks with flat, wind-abraded surfaces.
What is deflation?
The removal of cla, silt, and sand particles from the land surface by wind.
What is a blowout?
A depression on the land surface caused by wind erosion.
What is Loess?
A fine grained deposit of wind blown dust.
What is a slip face?
The steep, downwind slope of a dune; formed from loose, cascading sand that generally keeps the slope at the angle of repose.
What is a barchan dune?
A crescent shaped dune with the horns of the crescent pointing downwind.
What is a transverse dune?
A relatively straight, elongate dune oriented perpendicular to the wind.
What is a parabolic dune?
A deeply curbed dune in a region of abundant sand. The horns point upwind and are often anchored by vegetation. The difference between this and a barchan dune is the vegetation.
What are longitudinal dunes?
Large, symmetrical ridge of sand parallel to the wind direction.
What is the least resistant rock to erosion in the desert?
Shale.
