Glaciers and Geography
Take-Away Points
1. The Pleistocene glaciers profoundly affected
world geography and history
2. The Missouri and Ohio Rivers were created
because the glaciers blocked existing rivers
3. The Great Lakes were excavated by the
glaciers
4. The English Channel was formed because the
glaciers blocked existing rivers
5. The ice affected migration of humans into the
Americas
Northern Hemisphere Ice Caps
Drainage
Diversion,
Missouri River,
North Dakota
Mid-Pleistocene Drainage in the Midwest
Pre-Pleistocene Drainage in the Midwest?
Ice
Retreat,
Canada
Glacial Retreat, Europe
Pluvial
Lakes,
Southwest
U.S.
Pleistocene Rivers, Indonesia
Excavation of Great Lakes Basins
Occasional Re-Advances
Northeast Tilting of Crust
Lakes in Hudson Bay Basin
Sea Floods Hudson’s Bay
The Present North Sea
Pleistocene Western Europe
Pre-Pleistocene Western Europe
Siberian Super-Rivers?
Coming to
America
Take-Away Points
• The Pleistocene glaciers profoundly
affected world geography and history
• The Missouri and Ohio Rivers were created
because the glaciers blocked existing rivers
• The Great Lakes were excavated by the
glaciers
• The English Channel was formed because
the glaciers blocked existing rivers
• The ice affected migration of humans into
the Americas