Lake Bassano was a

proglacial lake In geology, a proglacial lake is a lake formed either by the damming action of a moraine during the retreat of a melting glacier, a glacial ice dam, or by meltwater trapped against an ice sheet due to isostatic depression of the crust around th ...

that formed in the Late

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

during the deglaciation of south-central

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...

by the impoundment of a re-established drainage system and addition of glacial meltwater. It is associated with the development of through-flowing drainage within the

Red Deer River The Red Deer River is a river in Alberta and a small portion of Saskatchewan, Canada. It is a major tributary of the South Saskatchewan River and is part of the larger Saskatchewan-Nelson system that empties into Hudson Bay. Red Deer River h ...

basin in particular, and the South

Saskatchewan Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North Dak ...

drainage network in general. Approximately of the Bassano basin is covered with

lacustrine 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 ...

sediments. These

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sa ...

s are bordered by the topographically higher '' Buffalo Lake Moraine'' to the west, the ''Suffield Moraine'' to the east and the ''Lethbridge Moraine'' to the south. The transmission of water through the basin was ultimately controlled by the regional topography and the position of the ice front. As 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 year ...

retreated, lower outlet channels were exposed. The lake levels at any given time were constrained by the elevation of the lowest drainage channel. As Glacial Lake Bassano, and the

system as a whole developed, throughflow in individual channels waxed, waned, and reversed, depending on the systemic controls.

Proglacial Lake System

The retreat of the late

Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...

an Laurentide Ice Sheet in Alberta was accompanied by the deposition of extensive areas of proglacial lake sediments associated with ice frontal positions. These lakes formed as a result of impoundment of the re-established proglacial drainage system and

glacial A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...

meltwater. estimates that roughly 50% of Alberta was occupied by these short-lived lakes. The mapping of sediments deposited by lacustrine and related glacial processes allows the determination of ice-frontal positions at sequential recessional phases. , for example, constructed a detailed and comprehensive series of glacial-marginal positions for north-central Alberta. There are, however, a wide variety of chronological interpretations and problems related to the proposed ice-marginal positions in

Southern Alberta Southern Alberta is a region located in the Canadian province of Alberta. In 2004, the region's population was approximately 272,017.deglacial landscape. Early work was hampered by a lack of precise elevational control; later work has suffered from a paucity of

chronological Chronology (from Latin ''chronologia'', from Ancient Greek , ''chrónos'', "time"; and , '' -logia'') is the science of arranging events in their order of occurrence in time. Consider, for example, the use of a timeline or sequence of events. ...

control and the lack of any detailed study of the integrated relationships between the proglacial lakes in southern Alberta. By topographic analysis, it is possible to accurately determine the sequence of formation and drainage, as well as the maximum and minimum elevations of the proglacial lakes In southern Alberta, the network of proglacial lakes lowered, with recession of the Laurentide Ice Sheet, from the maximum elevation of Glacial Lake McLeod to the final elevation of Glacial Lake Empress. The confluence of flow through Glacial Lakes Drumheller, Gleichen and Lethbridge utilized Etzikom Coulee to enter the Missouri Drainage System. When

Etzikom Coulee Etzikom Coulee is a coulee located in Southern Alberta, Canada. The waterway was formed as a glacial spillway channel at the end of the last ice age. Course The Etzikom Coulee begins northeast of the town of Stirling, and makes its way southea ...

was abandoned at (the height of the Lethbridge Moraine Divide) discharge from the lakes was entirely within Alberta. Glacial Lake

Drumheller Drumheller is a town on the Red Deer River in the badlands of east-central Alberta, Canada. It is northeast of Calgary and south of Stettler. The Drumheller portion of the Red Deer River valley, often referred to as Dinosaur Valley, has a ...

abandoned the Strathmore Channel at , whereupon discharge was directed through the smaller Crowfoot channel until . At this elevation, flow must have been diverted further to the east, over the Bassano basin. Glacial Lake Gleichen abandoned the southward-flowing McGregor Lake Channel at and discharged eastward into Glacial Lake Bassano until channelization occurred at . With recession of the ice, Glacial Lake Lethbridge lowered and extended eastward, forming Glacial Lake Taber, whose upper level was controlled by Chin Coulee at . Subsequent drainage flowed through Forty Mile Coulee until and along the valley of the South Saskatchewan, which became channelized at . Glacial Lake Medicine Hat formed at roughly and ponding at that location was associated with the formation of Glacial Lake Empress to the north at roughly the same elevation. Glacial Lake Bassano existed from a maximum elevation of until final drainage at . Its initiation coincides with the abandonment of southward-flowing drainage into the Missouri System and the beginning of drainage within Alberta. Together with Glacial Lake Tilley to the south, Glacial Lake Bassano received the discharge from over of the Laurentide Ice Sheet and associated proglacial lakes.

References

* * * * * * * * * * * * * * {{DEFAULTSORT:Bassano, Lake Former lakes of North America Glacial lakes of Canada