Retreat of the Glaciers
Our glacial deposits are largely the result of the great continental glacial melt event that ended the Pleistocene. It was a massive retreat of a two-mile thick ice covering from North America.
The lobate shape of lakes Michigan and Huron are associated with lobes of the retreating glacial lobes. The ice did NOT move northward. Instead it just did not flow as far to the south before melting on the warming Earth in that direction. So “retreat” is associated with warming (longer warmer summers, and shorter warmer winters) so that glaciers could not sustain southward movement in the face of warming of Illinois, Indiana and Wisconsin.
By 9000 years ago the retreating ice lobes were in the Houghton area, with a thick ice lobe at Dollar Bay and an ice free area in Houghton itself. The Tech campus may represent a kame terrace, and the “canal” an outlet which drained water from a lake called Lake Duluth, which was located where the western part of Lake Superior is now.
Glacial Retreat is happening now also. A new film, Chasing Ice , documents the overwhelming statistics and rates of mountain glacier retreat. And the retreat is marked in all glacial areas of the earth.
GLERL noaa.gov
GLERL noaa.gov
nps.gov
nps.gov
