Champlain Sea

The Champlain Sea (French: Mer de Champlain) was a temporary inlet of the Atlantic Ocean, created by the retreating glaciers during the close of the last ice age.[1][2] The Sea 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 and Vermont.[3]

The mass of ice from the continental ice sheets had depressed the rock beneath it over millennia. At the end of the last ice age, while the rock was still depressed, the Saint Lawrence and Ottawa River valleys, as well as modern Lake Champlain, were below sea level and flooded with rising worldwide sea levels, once the ice no longer prevented the ocean from flowing into the region.[4] 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, Ontario, and farther up the Ottawa River past Pembroke.[5] 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 150 metres (490 ft) above the level of today's Saint Lawrence and Ottawa Rivers.[5]

The best evidence of this former sea is the vast clay plain deposited along the Ottawa and St. Lawrence Rivers.[6] This resulted in distinctive forest types,[7] and large wetlands. Other modern evidence of the sea can be seen in the form of whale fossils, (belugas, fin whales,[8] and bowhead whales) and marine shells[9] that have been found near the cities of Ottawa, Ontario, and Montreal, Quebec. There are also fossils of oceanic fish such as capelin.[10] The Sea also left ancient raised shorelines in the former coastal regions, and the Leda clay deposits in areas of deeper water.[11]

The northern shore of the lake was in southern Quebec where outcrops of the Canadian shield form the Eardley Escarpment. This escarpment still has distinctive plants that may date back to the sea.[12] The Eardley Escarpment is known locally as the Gatineau Hills; 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.

Champlain Sea
The Champlain Sea


  1. ^ L.J. Chapman and D.F. Putnam. 1951. The Physiography of Southern Ontario. University of Toronto Press, Toronto. 284 p. plus map in four sections.
  2. ^ Anderson, T.W. 1989. Vegetation changes over 12,000 years. Geos 18:39–47.
  3. ^ Lake Champlain Basin Atlas: Geology Page Archived July 20, 2008, at the Wayback Machine
  4. ^ "Paleoceanography of the Champlain Sea, Hanover Park, Canada". Archived from the original on 2004-12-21. Retrieved 2005-02-04.
  5. ^ a b 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.
  6. ^ Chapman, L.J. and D.F. Putnam. 1984. The Physiography of Southern Ontario. Third edition. Ontario Geological Survey, Special Volume No.2. Government of Ontario, Toronto.
  7. ^ Keddy, C.J. 1993. Forest History of Eastern Ontario. A report prepared for the Eastern Ontario Forest Group.
  8. ^ "Fossilworks: Gateway to the Paleobiology Database".
  9. ^ University of Calgary: Champlain Sea fossils Archived February 13, 2005, at the Wayback Machine
  10. ^ McAllister, D.E., C.R. Harrington, S.L. Cumbaa, and C.B. Renaud. 1988. "Paleoenvironmental and biogeographic analyses of fossil fishes in peri-Champlain Sea deposits in Eastern Canada". Pp 241–258 in Gadd, N.R. (ed.) The Late Quaternary Development of the Champlain Sea Basin. Geological Association of Canada, Special Paper 36.
  11. ^ "Residents seek reassurance in wake of deadly slide" The Globe and Mail, May 12, 2010.
  12. ^ Brunton, D. and J.D. Lafontaine. 1974. An unusual escarpment flora in Western Quebec. The Canadian Field-Naturalist 88(3):337–344.

Further reading

Gadd, N.R. (ed.) 1988. The Late Quaternary Development of the Champlain Sea Basin. Geological Association of Canada, Special Paper 36.

External links

Alexander Stewart Provincial Park

Alexander Stewart Provincial Park is a nature reserve in McNab/Braeside, Renfrew, Ontario, Canada, about 11 kilometres (7 mi) west of the centre of Arnprior. This nature reserve contains a hardwood forest of several species including Maple, American Beech, Basswood, Blue-Beech, and Bur Oak. The subsurface is clay silt, a remnant of the ice age Champlain Sea, and the site is at an elevation of 130 metres (430 ft). It is located at the northwest intersection of Maple Bend Road and Russett Drive.

Cobbs Lake Creek

Cobbs Lake Creek is a creek in Prescott and Russell County in eastern Ontario, Canada, which empties into the South Nation River.

In the early 1900, the Cobb Lake Drainage Scheme reduced a large area covered by water to a tiny little creek. The goal of the project (which cost 60 000$ at the time) was to expend agricultural production and to allow farmers to sow at an earlier date the flooded part of their farms.Nowadays, Cobbs Lake is a large shallow lake which forms around the creek during the spring thaw. Fields are found around the lake, and these fields are flooded during the early spring expanding the lake even more. This causes problems for local residents since it also floods nearby side roads. Thousands of migrating snow geese, Canada geese, and many dabbling ducks, such as northern shovelers and pintails, stop over in this location during the spring. The heavy clay soils of the region were deposited by the Champlain Sea, a shallow arm of the Atlantic which extended into this region at the end of the last ice age.

Drummond/North Elmsley

Drummond/North Elmsley is a township in eastern Ontario, Canada in Lanark County. It is situated on the north shore of the Rideau River between the town of Perth and the town of Smiths Falls. It is a predominantly rural municipality. The township offices are located in the hamlet of Port Elmsley.

Green's Creek (Ontario)

Green's Creek 45°28′00″N 75°34′35″W is a small tributary of the Ottawa River that flows through the community of Gloucester in eastern Ottawa. It has cut deeply into sediments of the Champlain sea, producing a complex mixture of forest types, from upland oak and pine to floodplain forest. As a consequence there are nearly 500 species of plants known from the area. There is a large area of silver maple swamp where it enters the Ottawa River; this is one of the most important wetland complexes along the south shore of the Ottawa River. Rare species include the only population of the provincially rare pinedrops (Pterospora andromeda) in the region, and the only regional population of witch-hazel (Hammamelis virginiana). The area is conserved as part of the Ottawa Greenbelt and 5.5 kilometres of walking trails have been maintained as part of the Green's Creek Valley conservation area.

Greens Creek is also geologically significant for its fine assemblage of fossil fish dating from the era of the Champlain Sea.

Lake Albany

Glacial Lake Albany was a prehistoric North American proglacial lake that formed during the end of the Wisconsinan glaciation. It existed between 15,000 and 12,600 years ago and was created when meltwater from a retreating glacier, along with water from rivers such as the Iromohawk, became ice dammed in the Hudson Valley. Organic materials in Lake Albany deposits have been carbon dated to approximately 11,700 years ago. The lake spanned approximately 160 miles (260 km) from present-day Newburgh to Glens Falls.Lake Albany drained about 10,500 years ago through the Hudson River due to post-glacial rebound. When the lake drained it exposed the sandy and gravelly glaciolacustrine deposits left by the glacier, along a broad plain just west of Schenectady, where the Mohawk emptied into the lake. Dune and deltaic sands, containing lenses of silty sand, silt and clay, compose the topsoil which now underlies the Albany Pine Bush. Beneath the surficial deposits are lake-bottom silt and clay, which overlie till and shale bedrock. A small rill caused by the lake's drainage created Patroon Creek, Sand Creek, Lisha Kill, Shaker Creek, Delphus Kill and the Salt Kill in the town of Colonie, New York.

Lake Frontenac

Lake Frontenac was a proglacial lake in the basin of what is now Lake Ontario.

The sudden influx of fresh water into the Atlantic, as the retreat of the Laurentian Glacier triggered a sudden drop in the lake's water level, may in turn have triggered the onset of the Younger Dryas, 1000-year period of renewed cooling approximately 12000 years ago.

Lake Saint Pierre

Lake Saint Pierre (French: Lac Saint-Pierre) is a lake in Quebec, Canada, a widening of the Saint Lawrence River between Sorel-Tracy and Trois-Rivières. It is located downstream, and northeast, of Montreal; and upstream, and southwest, of Quebec City. The end of the lake delimits the beginning of the estuary of Saint Lawrence.

This lake which is 32 kilometres (20 mi) long (excluding Sorel Islands) and 14 kilometres (8.7 mi) wide, is part of the St. Lawrence Seaway. Including its shoreline, islands, and wetlands, the lake is a nature reserve. The body of water is recognized as a Ramsar site and as a Biosphere Reserve, due to the presence of many marshes and wetlands that are frequented by waterfowl. Recreational activities on the river (such as fishing, boating, sailing, swimming, water skiing, nature observation) are active mainly in summer season. Sport fishing is particularly popular, including ice fishing, especially in the great bay of Pointe-du-Lac.

Around Lake Saint-Pierre, several recreational services are available including marinas, hotel services, restaurants, outfitters, docks, gas stations, and cruises.

Lake Stowe

Lake Stowe was a glacial lake that formed in Central Vermont approximately 15,000 years ago in the late Pleistocene epoch. After the Laurentide ice sheet retreated, glacial ice melt accumulated at the terminal moraine.The lake existed until the glacier had completely melted. Then it flowed out through the Lamoille River valley.The lake was named after Stowe, near where evidence of the lake was discovered.

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 York. It was a geographical predecessor of Lake Champlain. Once the glacier retreated far enough north, it drained into Glacial Lake Candona, the geologic predecessor of the St. Lawrence River.

At one time, Lake Vermont may have reached nearly as far south as to what is now Albany, New York. The surface of the lake was about 500 feet (150 m) above present day Lake Champlain, and was up to 900 feet (270 m) deep. The lake contained muddy water, and the sediment of Lake Vermont contains silt/clay varves, with silt being deposited during summer and clay during the less-energetic flow of winter.

The Laurentide Ice Sheet retreated north of what is now Burlington, Vermont, about 13,500 years ago, marking the beginning of Lake Vermont. The ice damming the water at the north end, at what is now Warwick, Quebec, failed catastrophically about 12,000 years ago. The lake dropped 300 feet (91 m) within hours or days. Eventually, when the glacier retreated far enough north, salt water swept in, replacing the larger, freshwater Lake Vermont with the smaller, saltwater Champlain Sea.

List of prehistoric lakes

This a partial list of prehistoric lakes. Although the form of the names below differ, the lists are alphabetized by the identifying name of the lake (e.g., Algonquin for Glacial Lake Algonquin). YBP = Years Before Present.

Mississippi Lake

Mississippi Lake is a lake in Lanark County in Ontario, Canada. Ontario's Mississippi River flows northeast and north through the lake. Several small creeks including Cranberry Creek, McCrearys Creek, and McGibbon Creek drain into the lake from adjoining forest and agricultural land. The lake is distinctive for having one side (to the north) that is part of the Canadian shield, while the other is mostly limestone. The lake is a remnant of the old Champlain Sea, which flooded eastern Ontario at the end of last ice age. The former shoreline of the sea can still be traced inland from the north shore of the lake.European settlement of the lake basin began ca. 1816 as settlers moved north of the Rideau into areas such as Franktown. Between the 1860s and 1920s there were steamboats linking Carleton Place to Innisville.The lake has two large and provincially significant wetlands. The larger occurs at the west end of the lake; here the Mississippi River enters the lake through the Innisville wetland, which is also one of the largest wetlands in Lanark County, and is designated an Area of Natural and Scientific Interest. Included within its boundaries is The Mississippi Lake National Wildlife Area. This wetland has large areas of silver maple swamp, flooded only in the spring, and, lower on the shore, important areas of marsh and aquatic vegetation. The western shore of the lake, including Kinch Bay, Code Bay and King Bay, also supports a diverse wetland which ranges from silver maple swamp to large areas of aquatic plants. Loons, bald eagles, osprey and herons are frequently sighted in these habitats. The ospreys and herons also breed inland from the lake, for example in the nearby Scotch Corners Wetland. The provincially significant Blanding's Turtle is known from the lake; its long-term survival likely depends upon sufficient nesting areas. Eels were once abundant, but hydroelectric dams downstream have all but eliminated this species from the lake and the watershed.

Muskrat Lake

Muskrat Lake is located in the Whitewater Region of Renfrew County, Ontario, Canada. Said to be the home of the lake monster Mussie. Muskrat Lake drains into Muskrat River. Other than a few cottages and campgrounds, Cobden, is the only community on the lake's shore. Along its eastern shores is Sturgeon Mountain

Like many other lakes Muskrat Lake was formed about 10,000 years ago when the glaciers of the last ice age receded. At that point it was superseded by the much larger Champlain Sea. Due to glacial recession the sea was brackish, its salt levels rising and falling over the years making it somewhat salty and somewhat fresh. About 6,000 years ago the water level dropped and the Champlain Sea disappeared, leaving behind the present day lakes and rivers.

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 Labradorian Glacier. This body of water drained eastward from Georgian Bay to the Ottawa valley. This was a period of isostatic rebound raising the outlet over time, until it opened the outlet through the St. Clair valley.

Ottawa River

The Ottawa River (French: Rivière des Outaouais, Algonquin: Kitchissippi) is a river in the Canadian provinces of Ontario and Quebec. For most of its length, it defines the border between these two provinces. It is a major tributary of the St. Lawrence River.


The phenomenon of paleoflooding is apparent in the geologic record over various spatial and temporal scales. It often occurred on a large scale, and was the result of either glacial ice melt causing large outbursts of freshwater, or high sea levels breaching bodies of freshwater. If a freshwater outflow event was large enough that the water reached the ocean system, it caused changes in salinity that potentially affected ocean circulation and global climate. Freshwater flows could also accumulate to form continental glacial lakes, and this is another indicator of large-scale flooding. In contrast, periods of high global sea level (often during interglacials) could cause marine water to breach natural dams and flow into bodies of freshwater. Changes in salinity of freshwater and marine bodies can be detected from the analysis of organisms that inhabited those bodies at a given time, as certain organisms are more suited to live in either fresh or saline conditions.

Quick clay

Quick clay, also known as Leda clay and Champlain Sea clay in Canada, is any of several distinctively sensitive glaciomarine clays found in Canada, Norway, Russia, Sweden, Finland, the United States and other locations around the world. The clay is so unstable that when a mass of quick clay is subjected to sufficient stress, the material behavior may change from that of a particulate material to that of a fluid.

Quick clay has a remolded strength which is much less than its strength upon initial loading. This is caused by its highly unstable clay particle structure.

Quick clay is typically originally deposited in a marine environment. In that environment, the positive charge of cations (such as Na2+) was able to bind clay particles with negative surface charge (typically silicates SOn-n) by balancing charge in the double layer. When the clay became uplifted and was no longer subjected to salt water conditions, rainwater infiltrated these clays and washed away the salts that allowed these clay particles to remain in a stable structure.

With shear stress, the lack of counterbalancing charge from salts in the quick clay results in clay particle repulsion and realignment of clay particles to a structure that is extremely weak and unstable. Quick clay regains strength rapidly, however, when salt is added, which allows clay particles to form complexes with one another.

Quick clay is found only in northern countries, such as Russia, Canada, Norway, Sweden, and Finland, and in Alaska, United States since they were glaciated during the Pleistocene epoch. In Canada, the clay is associated primarily with the Pleistocene-era Champlain Sea, in the modern Ottawa Valley, the St. Lawrence Valley, and the Saguenay River regions.Quick clay has been the underlying cause of many deadly landslides. In Canada alone, it has been associated with more than 250 mapped landslides. Some of these are ancient, and may have been triggered by earthquakes.

Scotch Corners Wetland

Scotch Corners Wetland is a provincially significant wetland complex located in Lanark County, Ontario, Canada. The 202 hectares (500 acres) area has a wide array of wetland types including swamps, marshes, vernal pools, beaver ponds and seepage areas. It forms the headwaters of several creeks that drain into Mississippi Lake.

Tollmann's bolide hypothesis

Tollmann's bolide hypothesis is a hypothesis presented by Austrian paleontologist Edith Kristan-Tollmann and geologist Alexander Tollmann in 1994. The hypothesis postulates that one or several bolides (asteroids or comets) struck the Earth around 7640 ± 200 years BCE, with a much smaller one approximately 3150 ± 200 BCE. The hypothesis tries to explain early Holocene extinctions and possibly legends of the Universal Deluge.The claimed evidence for the event includes stratigraphic studies of tektites, dendrochronology, and ice cores (from Camp Century, Greenland) containing hydrochloric acid and sulfuric acid (indicating an energetic ocean strike) as well as nitric acids (caused by extreme heating of air).

Christopher Knight and Robert Lomas in their book, Uriel's Machine, argue that the 7640 BCE evidence is consistent with the dates of formation of a number of extant salt flats and lakes in dry areas of North America and Asia. They argue that these lakes are the result remains of multiple-kilometer-high waves that penetrated deeply into continents as the result of oceanic strikes that they proposed occurred. Research by Quaternary geologists, palynologists and others has been unable to confirm the validity of the hypothesis and proposes more frequently occurring geological processes for some of the data used for the hypothesis. Dating of ice cores and Australasian tektites has shown long time span differences between the proposed impact times and the impact ejecta products.

White Lake (Ontario)

White Lake is a medium-sized lake of Ontario, Canada. It is located 60 km west of Ottawa, Ontario near Calabogie to the west and Arnprior to the north. It may be accessed via Highway 417 from Ottawa or Renfrew Country Road 511 from Perth. The town of White Lake lies on the northern shore of the lake.

The northern and western shores of White Lake mark the upper limit of the Champlain Sea which flooded the Ottawa Valley at the end of the last ice age.The lake dimensions are:

length: 10 miles / 16 km

area: 5608 acres / 2270 hectares

perimeter: 60.8 miles / 98 kmThe lake is marked in Canada by National Resources Canada with the CGNDB Unique Identifier: FDDES.

Continental glaciations
North America
Eurasia and
Time periods

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