Fluvioglacial Landforms

Question 1

Formation of outwash plains

Answer 1

Formed from outwash sediment carried by meltwater streams. Made up of materials brought down by the glacier which is then picked up and sorted and dropped by running water beyond position of ice front, deposition

Question 2

What are eskers

Answer 2

Long sinuous, winding ridges of sorted material that run in direction of ice advance. Often stratified(layered).
Meandering hills

Question 3

Formation of eskers

Answer 3

Formed by subglacial river deposition when ice was melting away.
Mark the course of streams that once carried subglacial meltwater beneath glacier

Question 4

Why do some eskers run up gentle gradients

Answer 4

Channel of streams would be restricted by ice walls so there would be considerable hydrostatic pressure.
Allow large load to be carried

Question 5

What are kames

Answer 5

Deposits of sorted and often stratified sand and gravel left by meltwater along front of melting ice sheets.
Irregular undulating mounds
Can collapse when ice supporting them melts

Question 6

What are outwash plains

Answer 6

Extensive, gently sloping areas of sands and gravel that form in front of a glaciers snout.

Question 7

Formation of kames

Answer 7

When cracks in ice fill with sediments and the ice melts and sediments fall to form a mound

Question 8

What are braided streams

Answer 8

When a stream splits off into little streams and material is deposited in the centre of them

Question 9

Formation of a braided stream

Answer 9

Channel becomes choked with coarse material because of marked seasonal variations in discharge . When discharge is low excess sediment is deposited, discharge is variable

Question 10

What are kettle holes/lakes

Answer 10

Series of small depressions filled with lakes/marshes

Question 11

Formation of kettle holes/lakes

Answer 11

When blocks of ice buried beneath flubioglacial material melts causing surface layer of debris above buried ice to slump. The hollow can then fill with water to from a kettle Lake

Question 12

What are varves

Answer 12

Layered deposits which reflect the seasonal flow of meltwater into lakes

Question 13

Formation of varves

Answer 13

Sediment carried by meltwater streams is deposited when water enters a proglacial lake as the energy of the stream is lost.
They vary in thickness and this shows how much melting happens