| Titre | Ice-flow history of the Laurentide Ice Sheet in the southwest Northwest Territories: a Shield to Cordillera transect |
| Télécharger | Téléchargements |
| |
| Licence | Veuillez noter que la Licence du gouvernement
ouvert - Canada remplace toutes les licences antérieures. |
| Auteur | Paulen, R C ;
Smith, I R; Ross, M; Hagedorn, G W; Rice, J M |
| Source | Commission géologique du Canada, Présentation scientifique 105, 2019, 1 feuille, https://doi.org/10.4095/315274  Accès ouvert |
| Image |  |
| Année | 2019 |
| Éditeur | Ressources naturelles Canada |
| Réunion | GAC-MAC-IAH 2019 / AGC-AMC-AIH 2019; Québec, QC; CA; mai 12-15, 2019 |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.4095/315274 |
| 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; Colombie-Britannique; Alberta |
| SNRC | 85A; 85B; 85C; 85D; 85E; 85F; 85G; 95A; 95B; 95G; 95H |
| Région | Grand lac des Esclaves; Fleuve Mackenzie; Pine Point; Fort Resolution; Hay River; Fort Providence; Wood Buffalo National Park; Kakisa Lake; Sambaa K'e; Lac à la Truite; Liard River; Fort Liard; Cameron
Hills; Kakisa; Jean Marie River; Slave River; Fort Smith; Horn Plateau |
| Lat/Long OENS | -124.0000 -112.0000 61.7500 60.0000 |
| Sujets | travaux de prospection; antecedents glaciaires; glaciation; Wisconsinien; écoulement glaciaire; trajectoires d'écoulement; déglaciation; retrait de la glace; dispersion des sédiments; profils de
dispersion; antecedents de sedimentation; milieu sédimentaire; structures sédimentaires; dépôts glaciaires; elements glaciaires; topographie glaciaire; erosion glaciaire; stries glaciaires; cannelures glaciaires; affouillements glaciaires;
linéations; tills; moraines; argiles; rainures glaciaires; analyses stratigraphiques; clastes; analyses texturales; pressions interstitielles; Calotte glaciaire Laurentide; Bouclier Canadien; Cordillère canadienne; Bassin sédimentaire de l'ouest du
Canada; Mine Pine Point ; directions d'écoulement glaciaire; courants glaciaires; traînées de dispersion; géologie des dépôts meubles/géomorphologie; stratigraphie; Sciences et technologie; Nature et environnement; Phanérozoïque; Cénozoïque;
Quaternaire; Paléozoïque; Mésozoïque; Crétacé; Dévonien; Précambrien |
| Illustrations | cartes de localisation; cartes géolscientiques généralisées; modèles altimétriques numériques; photographies; graphiques en étoile; images satellitaires |
| Programme | GEM2 : La géocartographie de l'énergie et des minéraux Cartographie des dépôts meubles du sud du Mackenzie du corridor de Mackenzie |
| Diffusé | 2019 10 03 |
| Résumé | (disponible en anglais seulement)
Fieldwork conducted since 2010 by the Geological Survey of Canada under the GEM1 and GEM2 programs has revealed a more complex glacial history for 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)
Il s'agit de l'affiche présentée à GAC-MAC-IAH à Québec, en mai 2019. Elle résume les indicateurs d'écoulement de glace pour le sud des
Territoires du Nord-Ouest dans le bassin sédimentaire de l'Ouest canadien, du Bouclier canadien à la Cordillère. |
| GEOSCAN ID | 315274 |
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