Icemargin Environments

1
Ice-margin Environments
2
Ice-margins?

• May be absolutely clean/sharp
• No deposit (erosional?)
• Commonly transitional

3
Ice-marginal Features
Till Ablation till
G-lac. Drift Dropstones
G-lac. Drift Kame delta
Till Lodgment
Till Moraines
Alluvium Kame terraces
Alluvium Outwash/drift
Alluvium Eskers
Alluvium Outwash
4
Ice-cored Moraines

• Schematic of ice-core melt
• Results in multiple moraines from one advance
• Example of melting ice-cored moraine

5
Ice-cored Moraines

• Schematic of ice-core melt
• Results in multiple moraines from one advance
• Example of melting ice-cored moraine

6
Marginal aprons

• High relief
• High winds
• Snow accumulation
• Ice advance incorporates snow into ice terminus

Moraine
7
Glacier Forelands
8
Kame Terrace

• Interaction between valley wall and glacier wall.
• Example Blackfoot River valley till/kame

Terminal moraine
Kame terrace
9
Pro-, Para-, and Periglacial

• Proglacial
• Adjacent to ice
• E.g., lakes, kames
• Paraglacial
• Related to ice
• E.g., outwash
• Periglacial
• Almost glacial
• E.g., rock glaciers

10
Ice-marginal Assemblages
Outwash
Till
Braids
Talus
D. flows
11
Ice-margin Environments Synthesis
Talus
Lateral moraine
Outwash
Terminal moraines
Glaciomarine delta