Week 6.2 Flashcards
Desert
One of the 2 types of dry climate. The driest of dry climates
Steppe
One of the 2 types of dry climate, a marginals and more humid desert that separates it from bordering humid climates
Rain shadow
Dry region that results in the leeward side
Cross bed
I
Wind Saltation
Wind blown sand that moves by skipping and bouncing across the surface
Wind Suspended load
Mostly silt because of the lack of chemical weathering (less clay)
Dune
A hill or ridge of wind deposited sand
Slip face
The steep leeward surface of a sand dune
Loess
Deposits of wind blown silt lacking visible layers, buff colored, capable of maintaining a nearly vertical cliff
How does wind carry its sediment load
Transports fine particles in suspension and larger as bed load. Less capable of picking up but can spread more than stream
What sizes of sediments can wind move
Grains of sand/ fine particles
What factors contribute to the type of dune that might result
Wind direction
Velocity
Sand availability
Amount of vegetation
What kind of sedimentary rocks form in this environment (desert / wind)
I
Bed load that wind carries
Sand grains
Alpine glacier
Glacier confined to a mountain valley, which in most instances had been a stream valley
Ice sheet
Very large thick mass of glacial ice flowing outward in all directions from one or more accumulation centers
Snowline
The lower limit of perennial snow
Zone of accumulation
The part of a glacier that is characterized by snow accumulation and ice formation. The outer limit of this zone is the snowline
Zone of wastage
The part of a glacier beyond the snowline, where annually there is a net loss of ice
Glacial budget
The balance or lack of balance between ice formation at the upper end of a glacier and ice loss in the zone of wastage
Glacial striations
Stretches and grooves on bedrock caused by glacial abrasion
Rock flour
Ground up rock produced by the grinding effect of a glacier
Till
UNSORTED sediment deposited directly by a glacier
Glacial erratic
An ice transported boulder that was not derived from the bedrock near its present site
Moraine
H
Different types of moraines
I
Outwash plain
Relatively flat gently sloping plain consisting of materials deposited by melt water streams in
Difference between continental Ice sheet and alpine glacier
Ice sheets cover a much larger area
In a glacial system, how is sediment created
Plucking:Meltwater penetrates the cracks of the bedrock beneath and freezes, as the water freezes and expands it pries rocks loose
Abrasion: as the glacier slides over bedrock it functions like sandpaper, smoothing and polishing it
What sizes of sediments can glaciers move
Large blocks
What is the shape and landscape after a glacier has been present
Rugged angular, sharp, mountain area, produced by erosion from ALPINE glaciers
What kind of sedimentary rocks form in this environment (glacial)
I
