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TitleIce-flow history of the Laurentide Ice Sheet in the southwest Northwest Territories: a Shield to Cordillera transect
AuthorPaulen, RORCID logo; Smith, RORCID logo; Ross, M; Hagedorn, G; Rice, JORCID logo
SourceGAC-MAC-IAH 2019: where geosciences converge/AGC-AMC-AIH 2019 : où les géosciences convergent; GAC-MAC-IAH Joint Meeting, Abstract volume vol. 42, 2019 p. 156 Open Access logo Open Access
LinksOnline - En ligne (complete volume, volume complet, PDF, 6.08 MB)
Alt SeriesNatural Resources Canada, Contribution Series 20180393
PublisherGeological Association of Canada
MeetingGAC-MAC-IAH 2019 / AGC-AMC-AIH 2019; Québec, QC; CA; May 12-15, 2019
Mediaon-line; digital
RelatedThis publication is related to Ice-flow history of the Laurentide Ice Sheet in the southwest Northwest Territories: a Shield to Cordillera transect
File formatpdf (Adobe® Reader®)
ProvinceNorthwest Territories
NTS75D; 75E; 85A; 85B; 85C; 85D; 85E; 85F; 85G; 85H; 95A; 95B; 95G; 95H
AreaGreat Slave Lake; Pine Point; Hay River; Liard River; Fort Smith; Slave River
Lat/Long WENS-124.0000 -110.0000 62.0000 60.0000
Subjectssurficial geology/geomorphology; geochronology; stratigraphy; Nature and Environment; Science and Technology; glacial history; Wisconsinian glacial stage; glaciation; deglaciation; ice flow; sediment dispersal; field work; depositional environment; glacial erosion; glacial features; glacial landforms; glacial deposits; glacial striations; glacial grooves; tills; clays; clasts; fabric analyses; provenance; bedrock geology; lithology; sedimentary rocks; shales; Laurentide Ice Sheet; Canadian Cordillera; Canadian Shield; Cordilleran Ice Sheet; Marine Isotope Stage 3; ice-flow directions; ice streams; Phanerozoic; Cenozoic; Quaternary; Mesozoic; Cretaceous
ProgramGEM2: Geo-mapping for Energy and Minerals Mackenzie Corridor, Southern Mackenzie Surficial Mapping
Released2019 05 01
AbstractFieldwork conducted since 2010 by the Geological Survey of Canada under the GEM programs has revealed a more complex glacial history of the southern Great Slave Lake region of the Northwest Territories than was previously reported. New reconstructions of the Laurentide Ice Sheet paleo-ice flow history have been established from field observations of erosional and/or depositional ice-flow indicators (e.g. striae, bedrock grooves, till clast fabrics, and streamlined landforms), new geochronological constraints, and interpretations of glacial stratigraphy. Three distinct ice-flow phases are consistently observed in areas proximal to the western margin of the Canadian Shield between the Slave River near Fort Smith and Hay River further west. These phases are: 1) an oldest southwest flow; 2) a long-term sustained ice flow to the northwest; and, 3) a youngest west-southwest flow during Late Wisconsin deglaciation, which includes extensions of the Great Slave Lake and Hay River ice streams further east than previous mapped. At Hay River approaching the eastern limit of soft Cretaceous bedrock of the Western Canada Sedimentary Basin, the ice flow pattern no longer shows the aforementioned consistent chronology. From Hay River to the Liard River, near the zone where the Laurentide and Cordilleran ice sheet coalesced, a thinning ice profile, topographic highlands such as the Cameron Hills and Horn Plateau, and the deep basin that Great Slave Lake currently occupies, played a significant role on the dynamics of the Laurentide Ice Sheet during early ice advance, retreat during Marine Isotope Stage 3, Late Wisconsin advance and deglaciation. Other factors, such as increased sediment supply and clay content from Cretaceous shale bedrock were also significant in influencing ice-sheet behaviour. The role of elevated porewater pressures over subglacial clay-rich sediments controlled the extent and dynamics of several discordant ice streams in upland and lowland regions within the study area.
Summary(Plain Language Summary, not published)
Synthesis of field observations and a regional ice-flow summary over areas studied in GEM-1 and GEM-2, across the Western Canada Sedimentary Basin, from the Canadian Shield to the Cordillera.

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