GEOG 2OC3 Lecture Notes - Lecture 4: Canadian Shield, Permafrost, Basalt
13 Sep 2020
School
Department
Course
Professor
Moraines:
- Ridges or mounds of glacial material deposited close to the ice margin, often associated
with uneven topography
Eskers:
- Winding ridges of stratified san d and gravel frequently kilometers long, possibly
formed from meltwater running through glacial tunnels.
The Great Lakes:
- The retreat of the glaciers around 10,000 years ago created depressions in the landscape
that were then filled with meltwater. - We call these the Great Lakes- The Canadian
Great Lakes contain 21 percent of the worlds surface fresh water
The Canadian Shield:
- the Canadian shield was originally a mountain chain and has since been worn down by
erosional processes.- The retreat of glaciers across the roots of the mountains scraped
off rock layers to expose the underlying bedrock- Erractis/ Dropstones are deposited by
retreating glacial ice, often rocks geographically and geologically unrelated to their
situation. - The largest erratic in Southern Ontario is the Bleasdell Boulder located near
Trenton (weighs 33,000 tons and is 8m in height.
Permafrost: Subsurface material that has remained in a frozen state for 2 or more
years.- Much of northern Canada is either continuous (always frozen) or discontinuous
(frozen for a part of the year) - there is a lot of infrastructure built on permafrost in the far
north.- What might happen to people’s buildings when climate change causes the
permafrost to warm?
lOMoARcPSD| 2151316
Document Summary
Ridges or mounds of glacial material deposited close to the ice margin, often associated with uneven topography. Winding ridges of stratified san d and gravel frequently kilometers long, possibly formed from meltwater running through glacial tunnels. The retreat of the glaciers around 10,000 years ago created depressions in the landscape that were then filled with meltwater. We call these the great lakes - the canadian. Great lakes contain 21 percent of the worlds surface fresh water. The canadian shield was originally a mountain chain and has since been worn down by erosional processes. The retreat of glaciers across the roots of the mountains scraped off rock layers to expose the underlying bedrock - erractis/ dropstones are deposited by retreating glacial ice, often rocks geographically and geologically unrelated to their situation. The largest erratic in southern ontario is the bleasdell boulder located near. Trenton (weighs 33,000 tons and is 8m in height.
