Lake Chippewa was a prehistoric proglacial lake. The basin is now
Lake Michigan
Lake Michigan is one of the five Great Lakes of North America. It is the second-largest of the Great Lakes by volume () and the third-largest by surface area (), after Lake Superior and Lake Huron. To the east, its basin is conjoined with that o ...
. It formed about 10,600 years
before present
Before Present (BP) years, or "years before present", is a time scale used mainly in archaeology, geology and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Becaus ...
(YBP). The lake occupied the depression left by the
Michigan Lobe of the
Laurentide Ice Sheet
The Laurentide Ice Sheet was a massive sheet of ice that covered millions of square miles, including most of Canada and a large portion of the Northern United States, multiple times during the Quaternary glacial epochs, from 2.58 million years a ...
.
[University of Wisconsin, Green Bay, Dept of Geology]
Origin
The lake formed from glacial
Lake Algonquin
Lake Algonquin was a prehistoric proglacial lake that existed in east-central North America at the time of the last ice age. Parts of the former lake are now Lake Huron, Georgian Bay, Lake Superior, Lake Michigan, Lake Nipigon, and Lake Nipissing ...
as water levels dropped, occupying only the deepest parts of the
Lake Michigan
Lake Michigan is one of the five Great Lakes of North America. It is the second-largest of the Great Lakes by volume () and the third-largest by surface area (), after Lake Superior and Lake Huron. To the east, its basin is conjoined with that o ...
basin. The waters drained through the
Straits of Mackinac
The Straits of Mackinac ( ; french: Détroit de Mackinac) are the short waterways between the U.S. state of Michigan's Upper and Lower Peninsulas, traversed by the Mackinac Bridge. The main strait is wide with a maximum depth of , and connects ...
, then across
Lake Stanley
Lake Stanley, also called the ''Stanley unconformity'', is a postglacial freshwater lake that occupied part of what is now the basin of Lake Huron during a hydrologically significant period from 10,000 years Before Present (B.P.). The lake’s s ...
into either
Lake Hough
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...
and then to the
St. Lawrence River
The St. Lawrence River (french: Fleuve Saint-Laurent, ) is a large river in the middle latitudes of North America. Its headwaters begin flowing from Lake Ontario in a (roughly) northeasterly direction, into the Gulf of St. Lawrence, connecting ...
by way of the
Ottawa River
The Ottawa River (french: Rivière des Outaouais, Algonquin: ''Kichi-Sìbì/Kitchissippi'') is a river in the Canadian provinces of Ontario and Quebec. It is named after the Algonquin word 'to trade', as it was the major trade route of Eastern ...
valley, or through the
St. Clair and
Detroit
Detroit ( , ; , ) is the largest city in the U.S. state of Michigan. It is also the largest U.S. city on the United States–Canada border, and the seat of government of Wayne County. The City of Detroit had a population of 639,111 at th ...
rivers to an
Early Lake Erie
Early Lake Erie was a prehistoric proglacial lake that existed at the end of the last ice age approximately 13,000 years ago. The early Erie fed waters to Glacial Lake Iroquois.
The ancient lake was similar in size to the current lake during glaci ...
and out the
Niagara River
The Niagara River () is a river that flows north from Lake Erie to Lake Ontario. It forms part of the border between the province of Ontario in Canada (on the west) and the state of New York (state), New York in the United States (on the east) ...
towards the St. Lawrence. Around 10,300 YBP, Lake Chippewa’s levels continued to drop, and the basin was a self-contained body of water without an outlet. Levels returned and Lake Chippewa again flowed through the canyon at Mackinac until around 7,500 YBP. At that time, the
Nipissing Great Lakes
Nipissing Great Lakes was a prehistoric proglacial lake. Parts of the former lake are now Lake Superior, Lake Huron, Georgian Bay and Lake Michigan. It formed about 7,500 years before present (YBP). The lake occupied the depression left by the L ...
merged with the waters in the Michigan Basin and created a single lake encompassing all three of the upper
Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...
.
Size
Somewhat smaller than Lake Michigan, Lake Chippewa extended through the most of the Michigan Basin, north to the Straits of Mackinac, where there was a narrow channel which conveyed the lake's outflow over the now submerged Mackinac Falls to
Lake Stanley
Lake Stanley, also called the ''Stanley unconformity'', is a postglacial freshwater lake that occupied part of what is now the basin of Lake Huron during a hydrologically significant period from 10,000 years Before Present (B.P.). The lake’s s ...
. Its shoreline ranged from out from the present day Lake Michigan shore.
See also
*
Lake Chicago
Lake Chicago was a prehistoric proglacial lake that is the ancestor of what is now known as Lake Michigan, one of North America's five Great Lakes. Fed by retreating glaciers, it drained south through the Chicago Outlet River.
Origin
The cit ...
References
External links
* {{cite map , publisher= Randall Schaetzl, Michigan State University , title= Glacial Lakes Chippewa and Stanley , url= http://geo.msu.edu/extra/geogmich/chippewa.html, edition= , section= , accessdate= January 27, 2020
Moraines of the United States
Geological history of the Great Lakes
Geology of Illinois
Geology of Michigan
Geology of Wisconsin