Zusammenfassung der Ressource
Fluvioglacial depositional landforms
- Outwash plains
- Found in front of glacier's
snout, consisting of flat
expanse of sorted material
- Coarsest material
closest to snout and finer
material found further
along the plain. Stratified - layered vertically.
- Material rounded to
sub-rounded. May be
characterised by
small water filled
depressions (kettle
lakes) and crossed by
braided meltwater
streams
- Kelling Heath
North Norfolk
- Meltwater streams high in energy, high
velocities and high competence - can
carry high volumes of sediment.
- Meltwater streams emerge from ice front, increase
in friction and slow down, depositing material
- Largest material deposited first, sorted
deposit. Meltwater streams seasonal -
deposits stratified; layered vertically.
- Because of marked seasonality in meltwater
flow, streams may become choked with coarse
material and streams crossing outwash plains
are usually braided because of this.
- Kettle lakes
- A small circular hollow in outwash plain,
filled with water.
- Diameter 5-100 m and depth 1-5m
- During ice retreat blocks of ice (dead ice) may
become detached and outwash deposits build
up around and bury them.
- When ice eventually melts,
overlying deposits subside creating
a small hollow in the outwash plain
in which water accumulates to form
a lake.
- Kames
- Mounds of fluvioglacial
material sorted and often
stratified, found on the valley
floor. Kames may be a few
hundred metres long and tens
of metres high
- Form where sediments build up on surface in
crevasses and depressions as meltwater flows
into them. Sediment builds up into mound, as ice
melts sediment gradually lowered and deposited
- Some kames are delta kames which are
produced by glacial streams emerging at snout
of glacier, falling into glacier floor. ose energy
and deposit load.
- Some are result of supraglacial streams depositing material.
- Eskers
- Varves
- Fluvioglacial landforms
consist of fluvioglacial material
which has been deposited by
meltwater streams. Meltwater
streams may be supraglacial or
subglacial (at base).
- Turbulent flow of meltwater streams enables them to
carry large volumes of sediment, which is then
deposited.