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TitleOscillations of levels and cool phases of the Laurentian Great Lakes caused by inflows from glacial Lakes Agassiz and Barlow-Ojibway
AuthorLewis, C F MORCID logo; Anderson, T W
SourceJournal of Paleolimnology vol. 2, 1989 p. 99-146,
Alt SeriesGeological Survey of Canada, Contribution Series 42488
PublisherSpringer Nature
MeetingXIIth Congress of the Internationqal Union for Quaternary Research (INQUA); Ottawa, Ontario; CA; August 1987
Mediapaper; on-line; digital
File formatpdf
ProvinceOntario; Quebec
NTS30L; 30M; 30N; 31C; 31D; 31E; 31F; 31K; 31L; 31M; 31N; 32C; 32D; 32E; 32F; 40I; 40J; 40O; 40P; 41; 42A; 42B; 42C; 42D; 42E; 42F; 42G; 42H; 52A; 52B; 52G; 52H
AreaGreat Lakes; Lake Superior; Lake Huron; Lake Michigan; Lake Erie; Lake Ontario; Lake Nipigon; Thunder Bay; Marathon; Wawa; Georgian Bay
Lat/Long WENS -92.0000 -76.0000 50.0000 42.0000
Subjectssurficial geology/geomorphology; hydrogeology; geophysics; geochronology; glacial lakes; water levels; hydrologic environment; glacial deposits; radiocarbon dates; radiometric dates; stratigraphic analyses; lithology; palynology; fossils; cores; acoustic surveys; geophysical surveys; drainage patterns; paleoclimates; pollen analyses; Glacial Lake Agassiz; Glacial Lake Ojibway; Glacial Lake Barlow; Quaternary
Illustrationssketch maps; photographs
AbstractTwo distinct episodes of increased water flux imposed on the Great Lakes system by discharge from upstream proglacial lakes during the period from about 11.5 to 8 ka resulted in expanded outflows, raised lake levels and associated climate changes. The interpretation of these major hydrological and climatic effects, previously unrecognized, is mainly based on the evidence of former shorelines, radiocarbon-dated shallow-water sediment sequences, paleohydraulic estimates of discharge, and pollen diagrams of vegetation change within the basins of the present Lakes Superior, Michigan, Huron, Erie and Nipissing. The concept of inflow from glacial Lake Agassiz adjacent to the retreating Laurentide Ice Sheet about 11-10 and 9.5-8.5 ka is generally supported, with inflow possibly augmented during the second period by backflooding of discharge from glacial Lake Barlow-Ojibway. Although greater dating control is needed, six distinct phases can be recognized which characterize the hydrological history of the Upper Great Lakes from about 12 to 5 ka; 1) an early ice-dammed Kirkfield phase until 11.0 ka which drained directly to Ontario basin; 2) an ice-dammed Main Algonquin phase (11.0-10.5 ka) of relatively colder surface temperature with an associated climate reversal caused by greater water flux from glacial Lake Agassiz; 3) a short Post Algonquin phase (about 10.5-10.1 ka) encompassing ice retreat and drawdown of Lake Algonquin; 4) an Ottawa-Marquette low phase (about 10.1-9.6 ka) characterized by drainage via the then isostatically depressed Mattawa-Ottawa Valley and by reduction in Agassiz inflow by the Marquette glacial advance in Superior basin; 5) a Mattawa phase of high and variable levels (about 9.6-8.3 ka) which induced a second climatic cooling in the Upper Great Lakes area. Lakes of the Mattawa phase were supported by large inflows from both Lakes Agassiz and Barlow-Ojibway and were controlled by hydraulic resistance at a common outlet - the Rankin Constriction in Ottawa Valley - with an estimated base-flow discharge in the order of 200000 m3s-1. 6) Lakes of the Nipissing phase (about 8.3-4.7 ka) existed below the base elevation of the previous Lake Mattawa, were nourished by local precipitation and runoff only, and drained by the classic North Bay outlet to Ottawa Valley.

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