BSES 34 - DESERTS & WIND

Bed Load

Sediments too large or heavy to be carried in suspension by water or wind

Suspended Load

Silt and clay sized particles constitute most of this load

Deflation

The removal of loose surface sediment by wind erosion creates blowouts

Desert pavement

Left behind after wind has removed the finer-grained material

Dunes

Mound or ridge-shaped deposits of sand

Loess

Consists of windblown silt and clay deposit

Barchan Dunes

A crescent-shaped dune with tips point downwind

Longitudinal/Seif Dunes

Long parallel ridges of sand aligned generally parallel to wind direction

Transverse Dunes

Form long ridges perpendicular to the prevailing wind direction

Parabolic Dunes

Common in coastal areas with tips point upwind

Star Dunes

Pyramidal hills of sand with several ridges radiate from the crest

Coriolis effect

Describes the deflection of wind in the hemispheres due to the rotation of Earth

Internal drainage

A desert stream that never reaches the sea, depositing its load within its bed

Rock varnish

Coats many rocks with iron and manganese oxides

Alluvial Fans

Form when sediment-laden streams flow out from mountain fronts into the flat desert floor

Bajada

May form when alluvial fans coalesce

Playa

Results from the evaporation of a playa lake, leaving a salt pan

Pediments

Erosional bedrock surfaces

Inselberg

Resistant, projecting high in deserts

Mesas & Buttes

Steep sided, flat topped landforms