| Titre | Ice-flow history of the Laurentide Ice Sheet in the southwest Northwest Territories: a Shield to Cordillera transect |
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| Auteur | Paulen, R ; Smith,
R; Ross, M; Hagedorn, G; Rice, J |
| Source | GAC-MAC-IAH 2019: where geosciences converge/AGC-AMC-AIH 2019 : où les géosciences convergent; GAC-MAC-IAH Reunion conjoint, Volume de résumés vol. 42, 2019 p. 156  Accès ouvert |
| Liens | Online - En ligne (complete volume, volume
complet, PDF, 6.08 MB)
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| Image |  |
| Année | 2019 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20180393 |
| Éditeur | Association géologique du Canada |
| Réunion | GAC-MAC-IAH 2019 / AGC-AMC-AIH 2019; Québec, QC; CA; mai 12-15, 2019 |
| Document | publication en série |
| Lang. | anglais |
| Media | en ligne; numérique |
| Référence reliée | Cette publication est reliée à Ice-flow history
of the Laurentide Ice Sheet in the southwest Northwest Territories: a Shield to Cordillera transect |
| Formats | pdf (Adobe® Reader®) |
| Province | Territoires du Nord-Ouest |
| SNRC | 75D; 75E; 85A; 85B; 85C; 85D; 85E; 85F; 85G; 85H; 95A; 95B; 95G; 95H |
| Région | Grand lac des Esclaves; Pine Point; Hay River; Liard River; Fort Smith; Slave River |
| Lat/Long OENS | -124.0000 -110.0000 62.0000 60.0000 |
| Sujets | antecedents glaciaires; Wisconsinien; glaciation; déglaciation; écoulement glaciaire; dispersion des sédiments; travaux de prospection; milieu sédimentaire; erosion glaciaire; elements glaciaires;
topographie glaciaire; dépôts glaciaires; stries glaciaires; cannelures glaciaires; tills; argiles; clastes; analyses texturales; origine; géologie du substratum rocheux; lithologie; roches sédimentaires; schistes; Calotte glaciaire Laurentide;
Cordillère canadienne; Bouclier Canadien; Calotte glaciaire de la Cordillère; directions d'écoulement glaciaire; courants glaciaires; géologie des dépôts meubles/géomorphologie; géochronologie; stratigraphie; Nature et environnement; Sciences et
technologie; Phanérozoïque; Cénozoïque; Quaternaire; Mésozoïque; Crétacé |
| Programme | GEM2 : La géocartographie de l'énergie et des minéraux Cartographie des dépôts meubles du sud du Mackenzie du corridor de Mackenzie |
| Diffusé | 2019 05 01 |
| Résumé | (disponible en anglais seulement)
Fieldwork 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. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Synthèse des observations de terrain et d'un résumé du flux de glace régional sur les zones étudiées dans les régions GEM-1 et GEM-2, dans le
bassin sédimentaire de l'Ouest canadien, du Bouclier canadien à la Cordillère. |
| GEOSCAN ID | 313617 |
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