Fluvio-glacial landforms

how are fluvioglacial landforms created

meltwater can transport debris flowing under high pressure

meltwater slows and deposits in sorted manner from largest to smallest

which region of valley usually more dominated by f-g

down valley

how can subglacial streams flow upvalley

hydrostatic pressure

what will leave erosive marks

meltwater in contact with bedrock

nye channel

channels that cut downsides into bedrock

rothlisberger channel

cut upwards into ice itself

temporal changes to meltwater channels

last very little- only as long as temp high enough for liquid water

however eroded features can last longer

pro glacial lakes

ice melt and creates lake that develops on ice edge

channels created when lake overflows and can define new valleys

diverts rivers formed after deglaciation

eskers characteristics and formation

long ridges of material running in direction of ice advance

coarse material stratified

made by SUBglacial streams

temporal changes to eskers

last medium amount of time

size= difficult to erode but easier than rock composed features

beaded esker

esker ridge combined with other mounds of materials

kames characteristics and formation

meltwater damned by recessional moraine deposits

mounds in fan shape

Kame collapse as ice retreats

temporal changes to kames

last a medium amount of time- eroded and weathered

terraces

along glacial valley side and deposits of meltwater streams slowing between ice and valley side

(kames)

outwash plains c+F

found at front of glacial snout

finer material travels further

deposits layered vertically

temporal changes to outwash plains

last very little time- only sediment so easily eroded/ washed away

even less dominance in alpine regions where only seasonal

braided streams

meltwater streams that cross outwash plains

kettle holes

small depression filled with lakes formed where blocks of ice washed onto plain melt and leave gap in sediments

what do kettle holes lead to

peat formation

varves

layering shows year of deposition

seasonal variations in discharge

what will show summer discharge in varves and why

coarser material as more meltwater so more energy

what will show winter discharge in varves and why

less meltwater and less energy

how can varves indicate climate change

thickness variations

• thicker= more water so higher temps

• darker= more organic material so higher temps

7 fluvioglacial features

proglacial lakes
eskers
kames
outwash plains
braided streams
kettle holes
varves

where can these be found in the world

finland

alaska

lake district

iceland

japan

where can eskers- be found

finland

where can kames be found

lake district

where can outwash plains and braided streams be found

alaska

where can kettle holes be found

alaska

where can varves be found

varves

typical f-g landscape and why

s iceland

large outwash plain from ice cap

braided streams

sparse vegetation/ population

black sediment from volcanic rock