lifting of rocks
stages of glaciation in illinois
striations and rock flour
an amphitheater-shaped basin at the head of a glaciated valley
|LANDSCAPES PRODUCED BY ALPINE GLACIATION (valley glaciers)||
eroded triangular shaped cliffs in glaciated valleys
Mt. Russell and Mt. Carillon are pyramid-like in form. They were produced by the head ward erosion of glaciers that once occupied the valleys that nowsurround them.
|Two continents that contain continental glaciers||
Antartica and Greenland
specific types of till deposits that occurs on a glacier or left behind by a
|apart of two basic cycles||
a tributary that enters a glacial trough high above the floor of the trough
Occurs above the zone of plastic flow.
|What are drumlins?||
Long, smooth, canoe-shaped hills made of till. Usually found in swarms. Formed when a glacier ran over a preexisting moraine.
|What is a hanging trough?||
A tributary glacial valley.
- movement that occurs within a glacier(does not move at base)
|landforms created by erosion||
Landforms created by glacial erosion
Erosional features of glaciated valleys
Pater noster lakes
|zone of accumulation||
the area where a glacier forms
Elevation of the snowline varies greatly
Occured 1.6 or 1.8 million to 10,000 years ago during the Pleistocene Epoch.
Valleys that were once occupied by a glacier.
|What is firn?||
A rough, granular ice material found in a glacier.
|Sediment produced by glaciation is ____||
- ANGULAR, MULTI-SIZED, UNSORTED
|Eccentricity of orbitChanges in earth’s tiltPrecession of the equinoxes||
the 3 parts of Milakovitch's Theory
|What are glacial deltas?||
Formed when glacial streams empty into lakes.
|landforms made of stratified drift - ice contact deposits||
Deposited by meltwater flowing over, within, and at the base of motionless ice
|What is a terminal moraine?||
The deposit from the glaciers farthest advance.
|What is rock flour?||
A mixture of fine sand and silt formed by the crushing of rock under a glacier.
|LANDSCAPES FORMED BY CONTINENTAL GLACIATION||
- do not form rugged topography like alpine glaciers
- form rounded topography
- form grooved, striated bedrock and rounded elongated mountains
|What are the different sections of a glacier?||
The top 30-40 m are brittle (crevasses can form). The rest is called plastic. It is so dense that it is extremely hard(about a 5 on Mohs scale).
- Smooth, canoe/tearshaped
hills parallel to
direction of glacial
- Steep side faces the
direction from which
the ice advanced
Unsorted, unstratified material left by glaciers.
peak formed by 3 or
carved by running water
large boulder transported and deposited by a glacier. Sticks out does not match rocks in area
|What is Till||
sediments glaciers deposits
As latitude increases, snowline _______________
(Glacial deposit) An accumulation of unconsolidated material deposited by glaciers.
|rocks dragged along beneath glaciers are...||
long periods of freezing weather
A large, moving mass of ice.
[glacial] two eroding cirques may reduce an arete to a saddlelike depression or pass
|ice flow in?||
all dicection/ ice sheet
A type of metamorphic rock
|Zone of Fracture||
uppermost portion of glacier
glaciers that flow in valleys
Compacted and refrozen snow that hasn't become a glacier
Deposited by rivers, running water; sorted.
Glacial till marking the glacier's furthest advance.
A steep, bowl-shaped hole in the ground once covered by a glacier, formed when a block of ice left by a glacier melts.
cone-shaped hill of sand and gravel formed by the deposition of sediments in streams flowing over the top of the glacier
bands of light and dark sediments; summer and winter pattern of deposition (like ogive but of dirt)
is a jagged saw-tooth ridge formed between 2 adjacent glacial lobes moving to lower elevations
coalescence of two or more Alpine glaciers; usually occupying lowlands
any material carried and deposited by a glacier
a glacier in a mountain range
filled bowl-like hollows. found high on mountainsides
|A bowl-shaped depression formed by a glacier in the valley where it begins||
very small scratches found in the bedrock produced by the erosion of a glacier.
deposited as glacier retreats but doesn't stall...mostly flat
alternative bands of light and dark ice on a glaciers surface
dunes with a parabolic shape with horns that extend in the same direction as the wind
glacially eroded valleys have a ____ shape, as opposed to the ____ shape left by stream erosion
pooling of glacial meltwater in holes left by chunks of receding glacier
|Types of Sand Dunes||
barchan dunes, transverse dunes, longitudinal dunes, parabolic dunes and star dunes
When two glaciers come together, and their sediments do too, and they are now in the middle instead of on the edge.
A fine sediment of pulverized rock produced by glacial erosion
an unsorted mixture of rock materials deposited as a glacier melts
glaciers that cover large areas that form when temperatures remain cold enough to allow snow and ice to accumulate
where a glacier melts a deposits sediment that it has eroded from the land
glacier is advancing, alpine to lower elevations, continental to lower latitudes
glacial slips/slides on a think layer of mud at the bottom of a glacier.
end moraines that form at farthest edge of toe advance
a vertical but windy tunnel in a glacier carved by a surface stream
a small depression that forms when a chunk of ice is left in glacial till
A glacial valley that has been filled by the sea
a pyramid like peak formed by glacial action in 3 or more cirques surrounding a mountain summit.
smaller ice sheet , may be in mountains
the middle of the ice; form where glaciers join; debris mostly on top of the ice
process by which a block of a glacier breaks off and falls into the sea to form an iceberg
part of glacier where ice stays with itself, doesnt deform much
a section of a glacier that flows down a steep gradient so that the ice fractures into numerous crevasses and towering ice pinnacles
highest and coldest part of a glacier where snow buildup occurs
periods of time where all the glaciers are advancing. many ice ages in history of earth only takes a 10 degree drop in temperature to go into the ice age.
eroded by passage of valley glacier - longitudinal profile is steep, irregular and stepped - u-shaped and typically straight
all sediment deposited as a result of glacial erosion
when a glacier melts it deposits the sediment it eroded from the land, creating this
A lake high in the mountains in a dip
|Describe the trophosphere||
*Lowest Layer*Contains 80% of mass of the atmosphere*where weather occurstemperature decreases with height
a large mass of ice in the middle of an ocean
|Zone of Wastage||
there is a net loss to the glacier
|Glacial erosion: explain proccesses and describe resulting landforms; plucking||
Plucking- fracturing and lifting up rock blocks
|The Principle of Uniformitarianism||
"The Present is Key to the Past"
|How do glaciers lose mass?||
Ablation (it melts, breaks off)Loss of snow/ ice from melting, calving, sublimation, etc.
|Zone of ablation||
Where snow / ice is lost due to melting, sublimation, or calving.
|Continental Glaciers (Ice sheets)||
- Exist on a larger scale than valley glaciers
- Two major ice sheets on Earth are over Greenland and
- Cover large land areas
|Two of the Many Hypotheses for the Cause of Glacial Ages Involve...||
plate tectonics and variations in Earth's Orbit
|Seal level rise associated with ice melting||
if melted, sea would rise 60 to 70 meters