Mountain Glaciers

Question 1

Are mountain glaciers more or less erosive than ice sheets?

Answer 1

Typically less, but produce significant depositional landforms.

Question 2

What are moraines? Where do they form in relation to glaciers?

Answer 2

Ridges and mounds formed on the boundaries of glaciers.

Question 3

What are the two types of ways moraines can form?

Answer 3

• Deposition from a stationary glacier boundary.
• or squeezing, pushing and thrusting motions on existing sediment.

Question 4

What’s the most common type of moraine in Britain? Where are these usually found?

Answer 4

Hummocky moraines.
In valley bottoms and lower slopes

Question 5

What are the 3 process of hummocky moraine formation?

Answer 5

• Undeformed ice-contact fan.
• Pro-glacially deformed fan
• Overridden fans

Question 6

Describe the process of undeformed ice-contact fan hummocky moraines?

Answer 6

debris flowing off the glacier creates a stacked fan which collapses to create to a crest when the glacier retreats.

Question 7

Describe the process of pro-glacially deformed ice-contact fan hummocky moraines?

Answer 7

Forms as an un-deformed fan would, but readvance of the glacier causes deformation of the deposited sediment.

Question 8

Describe the process of overridden fans hummocky moraines?

Answer 8

Has pro-glacial deformation due to readvance and subglacial deformation where the glacier overrides the moraine (leads to a less defined crest)

Question 9

What are drift limits? Where are they very common

Answer 9

A limit on mountain slopes where inside these limits, thick glacial sediments are seen.
Very common in Scotland especially.

Question 10

What are glaciolacustrine associations? What can they lead to the formation of?

Answer 10

Depositions due to ice contact with a lake – due to meltwater flow out of the glacier which delivers sediment.
- Can form sub-aqueous moraines

Question 11

What is dissected glaciogenic material very similar to? How are they differentiated?

Answer 11

Moraines, when viewed on ground level.
The sediment in dissected glaciogenic material is unrelated to its shape, showing it has been carved not deposited by the glacier.

Question 12

What does dissected glaciogenic material show us?

Answer 12

The interconnected formation shows us meltwater flow channels within the glacier

Question 13

What are the five main glacial landsystem models?

Answer 13

Ice cap
Lowland and piedmont lobe
Alpine icefields
Plateau icefields
Cirque/niche glacier

Question 14

Describe alpine ice-fields.

Answer 14

A system of interconnected, steep sided glacial valleys with hummocky morraines.

Question 15

Describe plateau icefields.

Answer 15

Similar to alpine icefields, but landforms like moraines continue onto plateaus.

Question 16

What is the most distinctive feature of an ice cap landsystem?

Answer 16

Landforms are often discordant with topography because icecaps are unconstrained.

Question 17

What and when was the Loch Lomond readvance?

Answer 17

Last period of glaciation in Britain, approx 12.9-11.7 thousand years ago (right at the end of the Pleistocene)

Question 18

What glacier types were seen most in Britain during the Loch Lomond readvance?

Answer 18

mostly terrestrial mountain glaciers.