The Champlain Sea (french: Mer de Champlain) was a prehistoric

inlet An inlet is a (usually long and narrow) indentation of a shoreline, such as a small arm, bay, sound, fjord, lagoon or marsh, that leads to an enclosed larger body of water such as a lake, estuary, gulf or marginal sea. Overview In marine geogra ...

of the Atlantic Ocean into the North American continent, created by the retreating ice sheets during the closure of the last glacial period. The inlet once included lands in what are now the Canadian provinces of Quebec and Ontario, as well as parts of the American states of

New York New York most commonly refers to: * New York City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * '' ...

and Vermont.

Origins

The mass of ice from the continental ice sheets had depressed the rock beneath it over millennia. At the end of the last glacial period, while the rock was still depressed, the

Saint Lawrence Saint Lawrence or Laurence ( la, Laurentius, lit. "Laurel wreath, laurelled"; 31 December AD 225 – 10 August 258) was one of the seven deacons of the city of Rome under Pope Sixtus II who were martyred in the Persecution of Christians, perse ...

and

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 ...

valleys, as well as modern Lake Champlain, at that time the

Lake Vermont Lake Vermont, also called Glacial Lake Vermont, was a temporary lake created by the retreating glaciers during the close of the last ice age. The lake once included land in the Canadian province of Quebec and the American states Vermont and New ...

, were below sea level and flooded with rising worldwide sea levels, once the ice no longer prevented the ocean from flowing into the region. As the land gradually rose again, in the process known as isostatic rebound, the sea coast gradually retreated to its current location. The sea lasted from about 13,000 years ago to about 10,000 years ago and was continuously shrinking during that time, since the rebounding continent was slowly rising above sea level. At its peak, the sea extended inland as far south as Lake Champlain and somewhat farther west than the city of

Ottawa Ottawa (, ; Canadian French: ) is the capital city of Canada. It is located at the confluence of the Ottawa River and the Rideau River in the southern portion of the province of Ontario. Ottawa borders Gatineau, Quebec, and forms the core ...

, Ontario, and farther up the Ottawa River past Pembroke. The remaining glaciers fed the sea during that time, making it more brackish than typical seawater. It is estimated that the sea was as much as above the level of today's Saint Lawrence and Ottawa Rivers.Barnett, P.J. 1988. History of the northwestern arm of the Champlain Sea. Pp 25–36 in Gadd, N.R. (ed.) ''The Late Quaternary Development of the Champlain Sea Basin''. Geological Association of Canada, Special Paper 36. Map 5.

Geological evidence

The best evidence of this former sea is the vast clay plain deposited along the Ottawa and St. Lawrence Rivers. This resulted in distinctive forest types, and large wetlands. Other modern evidence of the sea can be seen in the form of fossils of whales ( belugas, fin whales, and

bowhead whale The bowhead whale (''Balaena mysticetus'') is a species of baleen whale belonging to the family Balaenidae and the only living representative of the genus ''Balaena''. They are the only baleen whale endemic to the Arctic and subarctic waters, ...

s), walruses and other pinnipeds, and marine shells that have been found near the cities of Ottawa, Ontario, and Montreal, Quebec. There are also fossils of oceanic fish such as capelin. The Sea also left ancient raised shorelines in the former coastal regions, and the Leda clay deposits in areas of deeper water. The northern shore of the lake was in southern Quebec where outcrops of the

Canadian Shield The Canadian Shield (french: Bouclier canadien ), also called the Laurentian Plateau, is a geologic shield, a large area of exposed Precambrian igneous and high-grade metamorphic rocks. It forms the North American Craton (or Laurentia), the anc ...

form

Eardley Escarpment The Gatineau Hills (french: Collines de la Gatineau) are a geological formation in Canada that makes up part of the southern tip of the Canadian Shield, and acts as the northern shoulder of the Ottawa Valley. They are also the foothills of th ...

. This escarpment still has distinctive plants that may date back to the era when the sea existed.Brunton, D. and J.D. Lafontaine. 1974. An unusual escarpment flora in Western Quebec. The Canadian Field-Naturalist 88(3):337–344. The Eardley Escarpment is known locally as the Gatineau Hills. It is part of the Mattawa fault at the southeastern edge of the Ottawa-Bonnechere Graben, in Eastern Ontario and the Outaouais region of Quebec, more commonly known as the Ottawa Valley.

References

External links

History of the Champlain Sea

Charlotte, The Vermont Whale
* https://web.archive.org/web/20070513190043/http://www.lesaventuresdupatrimoine.com/joly/gardiens/gar14.html * http://www.civilization.ca/cmc/archeo/kichisibi/champlain/f3-0.htm * http://www.ggl.ulaval.ca/personnel/bourque/s3/retrait.glaces.html {{Authority control Natural history of Ontario Natural history of Quebec Natural history of New York (state) Natural history of Vermont Pleistocene Seas of the Atlantic Ocean Last Glacial Period Glacial lakes of the United States Lake Champlain Seas of Canada

Origins

Geological evidence

See also

References

Further reading

External links