Glaciolacustrine and Glaciomarine Environments

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Glaciolacustrine and Glaciomarine Environments
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Ice Sheet Margins

• E.g., Laurentide Ice Sheet
• Lakes Great, Agassiz, McConnell
• Seas Champlain Tyrrell

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Laurentide Marine-based Evolution

• Not all lakes/seas, not all of the time
• But much of the margin, much of the time.

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Laurentide Marine-based Evolution

• Not all lakes/seas, not all of the time
• But much of the margin, much of the time.

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Laurentide Marine-based Evolution

• Not all lakes/seas, not all of the time
• But much of the margin, much of the time.

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Ice shelf retreat across water - gradual
ShelfEdge
PinningPoint
HingeLine
IceCliff
ShoreLine
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Ice advance into water

• Unknown!
• Grounded on bedrock?
• Grounded on proglacial sediment?
• Buttressed by pack ice?
• Buttressed by icebergs?

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Proglacial (floating ice) sediment

• Standard facies
• Till
• Lodgment
• Melt-out
• Outwash
• Stratified facies
• Dropstones

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Glaciomarine stratigraphy

• Alloformations (based on boundaries)
• Facies (based on transport mechanisms)

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Flowtills

• Debris flows of remobilized till
• Found in deltaic environments

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Flowtills

• Debris flows of remobilized till
• Found in deltaic environments

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Dropstones

• Manifestly out of place!
• May retain glacial character

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Proximal glaciomarine sediments

• Raised fiord sediments

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Proximal glaciomarine sediments

• Raised fiord sediments
• Grading upwards

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Proximal glaciomarine sediments

• Raised fiord sediments
• Grading upwards
• Sampled in place (paleomag and sediments)

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Proximal glaciomarine sediments