Glacial erosion and deposition

Glacial Abrasion

Rocks/particles transported at base, scratches

Glacial Plucking

an erosional process by which rocks are pulled out of the ground by a glacier

stoss and lee

Erosional Landforms

crag and tail

A glacially eroded hill with a tail of till formed down-glacier of it

Erosion by Glacial Meltwater

Fluvial abrasion and cavitation

what determines the amount of subglacier abrasion

rate and temperature

types of drift

stratified and non stratified

Stratified Drift

- Transported by moving water

- Fluvioglacial or glaciofluvial( under or infront of glacier)

• Well-sorted, clasts are more rounded

more glaciers are

dirty

drift

glacially deposited sediment

Nonstratified Drift

Till is single most variable type of sediment

- Angularity/roundness(if in middle of glacier)

- Particle size

- Transportation by glacier• Valley glaciers receive more from above

Lodgement till

sediment that accumulates at the base of a glacier and typically has a wide range of grain sizes (including clay) and is well compacted

- stuff lodged into the ground

Deformation till

Soft sediment deformation by glacial shear stress

- glacier as plow

flow till

- falls/pushed off front of glacier

sand bar

A long underwater ridge formed by sand deposited offshore, outwash plain

kettled sandbar

sandbar+kettle holes

moraine

A ridge formed by the till deposited at the edge of a glacier.

kames and esker

dominated by outwash

End of moraine/terminal

marks the farthest advance of the glacier

drumlin

-A long mound of till that is smoothed in the direction of the glacier's flow

drumlin formation reason why deposition

-subglacial depositional features

- subglacial molding into streamlined shape

-or infilling if cavities cut into basal ice by meltwater

drumlin formation reason why erosion

ice erodes, transports, streamlines existing deposits , if truly erosional see less till and more abrasion

kames

- tend to be hills

- made out of outwash/stratifies drift

- isolated hills with stratified drift

delta kames

lake seperated by huge blocks of ice

- meltwater to delta

kettle

glacial formed lakes when chunk of ice broke off and heavy enough to leave depression in topography,

esker

- depositis of subgalcial river

- heat energy through flowing water easier for flowing water to move up

most recent glacial advance

wisconcian