| Titre | Ice-flow and deglacial history of the Laurentide Ice Sheet in the southwestern Great Slave Lake area |
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| Auteur | Hagedorn, G; Ross, M; Paulen, R ; Smith, R; Neudorf, C; Gingerich, T; Lian,
O |
| 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. 102  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 20180388 |
| 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 and
deglacial history of the Laurentide Ice Sheet in the southwestern Great Slave Lake area, Northwest Territories |
| Formats | pdf (Adobe® Reader®) |
| Province | Territoires du Nord-Ouest |
| SNRC | 85B/09; 85B/10; 85B/11; 85B/14; 85B/15; 85B/16 |
| Région | Grand lac des Esclaves; Pine Point |
| Lat/Long OENS | -115.0000 -114.0000 61.0000 60.5000 |
| Sujets | antecedents glaciaires; déglaciation; écoulement glaciaire; marges glaciaires; retrait de la glace; paléodrainage; rapports sur le terrain; sediments; sables; dépôts glaciaires; tills; moraines;
échantillons de till; clastes; origine; analyses texturales; elements glaciaires; stries glaciaires; linéations; lacs glaciaires; niveaux d'eau; Calotte glaciaire Laurentide; Lac glaciaire de McConnell; directions d'écoulement glaciaire; lignes de
partage glaciaire; sédiments marins de plages; sédiments éoliens; géologie des dépôts meubles/géomorphologie; géochronologie; Nature et environnement; Sciences et technologie; Phanérozoïque; Cénozoïque; Quaternaire |
| 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)
Limited field studies and sparse chronological constraints in the southwestern Great Slave Lake area creates uncertainties about the Laurentide Ice Sheet (LIS)
flow history and deglacial chronology. Improved understanding of the western LIS ice-margin morphology and retreat history is required to refine larger ice-sheet interpretations and timing for northwest drainage of glacial Lake McConnell. Using new
field observations and geochronology we establish ice-flow history and better constrain regional deglaciation. Paleo-ice flow indicators (n = 66) show an oldest southwestern flow (230°), an intermediate northwesterly flow (305°), and a youngest
westerly flow (250°). Till samples bulk sediment and matrix properties (n = 160) allowed identification of two till units. A lower grey till sourced mainly from local Paleozoic sediments produced clast fabrics indicating a southwesterly flow
direction, overlain by a brown till that contained an increased Canadian Shield content with lodged elongate boulders a-axes and boulder-top striation orientations indicating a west to northwest ice-flow direction. Ice-flow results show a clockwise
shift in direction interpreted as evidence for ice-divide migration followed by topographically controlled deglacial westward flow influenced by the Mackenzie River valley. Minimum deglacial timing estimates were constrained through optical dating of
fine-sand deposits in a well-developed strandline (n = 2) and seven aeolian dunes; ages range from 9.9 ± 0.6 to 10.8 ± 0.7 ka BP. These ages are from dunes located below glacial Lake McConnell maximum water level and may thus provide new local lake
level age constraints. Ice retreat is informed by a newly-mapped segment of the Snake River moraine, which is an understudied feature in the region. New ice-flow history and ice-margin retreat interpretations will be integrated into the larger body
of work on the western LIS providing more confident conclusions on ice-sheet evolution and meltwater drainage pathways, specifically in the southwestern Great Slave Lake area. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Présentation d'un étudiant de maîtrise financé par GEM2 à la conférence géologique nationale du Canada, résumant les recherches sur le terrain
et les résultats de laboratoire. |
| GEOSCAN ID | 313593 |
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