Aeolian Processes Flashcards
What are aeolian processes?
Processes related to wind action, most pronounced in dry lands
Aeolian processes include erosion, transportation, and deposition by wind.
Define deflation in the context of aeolian erosion.
Wind’s shifting of loose particles in air or along the ground
Deflation can create features like blowouts.
What is a blowout?
A shallow depression from which fine material has been deflated
Blowouts are formed by the process of deflation.
What is abrasion in aeolian erosion?
Airborne sand and dust driven by wind against existing rock and soil surfaces
This process can pit, etch, and polish exposed rock.
What are ventifacts?
Rocks that have been shaped by sandblasting from the wind
Ventifacts are a result of aeolian abrasion.
How does aeolian transportation compare to fluvial transport?
Aeolian transportation is less effective than fluvial transport
Only fine particles of dust are carried in suspension.
What is saltation in aeolian transportation?
The bouncing of particles larger than dust along the ground
Saltation is a key mechanism for moving sand and other materials.
What are sand dunes?
Loose windblown sand piled into a mound or hill
Sand dunes are most notable aeolian deposits found in deserts and coastal areas.
What happens to sand dunes when wind prevails from one direction?
The dune may slowly migrate without changing shape
This migration is due to erosion on the windward slope and deposition on the leeward side.
Describe a barchan dune.
An individual or group of dunes migrating across a nonsandy landscape
Barchan dunes are crescent-shaped due to strong winds blowing consistently from one direction.
What is loess?
Wind-deposited, fine-grained silt that lacks horizontal stratification
Loess has great vertical durability and is believed to originate from glaciation and deflation from deserts.
What characterizes basin-and-range terrain?
Largely without external drainage, featuring normal faulting and fault-block mountain ranges
This terrain often has interior drainage basins.
Define a mesa.
A flat-topped surface
Mesas are often associated with escarpments.
What is a scarp?
A steep, nearly vertical cliff
Scarps are often formed by erosion or faulting.
What are badlands?
Intricately rilled and barren terrain of arid and semiarid regions
Badlands are characterized by erosion and lack of vegetation.
