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.