Laurentide ice sheet
The Laurentide Ice Sheet was a massive ice sheet that covered an extensive area during the last glacial period (known as the Wisconsin Ice Age in North America) that covered what is now eastern Canada and part of the United States between about 90,000 and 20,000 BC . The southern limit of the glaciation reached the area around today's cities of New York City and Chicago and ran along the Missouri to the west to the northern foothills of the Cypress Hills , behind which the ice sheet converged with the glaciers of the Cordilleras .
Towards the end of the last great ice age, an ice-free corridor opened between the glaciers of the Rocky Mountains and the Laurentide Ice Sheet . In climate history and paleontology , it is discussed whether and from when the corridor was passable for game and people following it. It is considered a possible migration route of the Paleo-Indians into the interior of the continent when colonizing America .
As it continued to melt, the glacier fed a glacial stream in the course of today's Mississippi River . For a period of well over 1000 years, its water masses in the middle and lower reaches are considered impassable for people with the technologies of the time.
→ See also: Canadian shield
Individual evidence
- ↑ Arthur S. Dyke, Victor K. Perst: Late Wisconsinan and Holocene History of the Laurentide Ice Sheet. In: Géographie physique et Quaternaire. 41, 1987, pp. 237-263, doi : 10.7202 / 032681ar .