| Titre | Ice-flow history and regional stratigraphy of the northwestern Laurentide Ice Sheet, evidence from the Great Slave Lake area |
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| Auteur | Hagedorn, G; Ross, M ; Paulen, R; Smith, R |
| Source | GAC®-MAC 2021, London, Canada: Exploring Geosciences Through Time and Space/GAC®-MAC 2021, London, Canada : Explorer les géosciences à travers le temps et l'espace; L'Association géologique du
Canada-L'Association minéralogique du Canada, Réunion annuelle conjointe, Recueil des résumés vol. 44, 2021 p. 122  Accès ouvert |
| Liens | Online - En ligne (complete
volume - volume complet, PDF, 2.45 MB)
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| Image |  |
| Année | 2021 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20210032 |
| Éditeur | Association géologique du Canada |
| Réunion | GAC-MAC 2021: Geological Association of Canada-Mineralogical Association of Canada Joint Annual Meeting 2021; London, ON; CA; Novembre 1-5, 2021 |
| Document | publication en série |
| Lang. | anglais |
| Media | numérique; en ligne |
| Formats | pdf |
| Province | Territoires du Nord-Ouest |
| SNRC | 85C; 85F |
| Région | Grand lac des Esclaves |
| Lat/Long OENS | -118.0000 -116.0000 62.0000 60.0000 |
| Sujets | antecedents glaciaires; glaciation; écoulement glaciaire; prospection minière; potentiel minier; méthodes d'exploration; dépôts glaciaires; tills; clastes; blocs; topographie glaciaire; lithologie des
galets; oxydes; origine; analyses texturales; Calotte glaciaire Laurentide; Bouclier Canadien; directions d'écoulement glaciaire; géologie des dépôts meubles/géomorphologie; stratigraphie; minéralogie; sédimentologie; géologie économique; Nature et
environnement; Sciences et technologie; Phanérozoïque; Cénozoïque; Quaternaire; Paléozoïque; Précambrien |
| Programme | GEM2 : La géocartographie de l'énergie et des minéraux Cartographie des dépôts meubles du sud du Mackenzie du corridor de Mackenzie |
| Diffusé | 2021 11 01 |
| Résumé | (disponible en anglais seulement)
Reconstructing the evolution of past ice sheets and understanding their net effect on landscapes and surficial sediments provide important insights into
long-term glacial processes, as well as useful knowledge for mineral exploration in glaciated terrains. The evolution of the northwestern Laurentide Ice Sheet is poorly understood due to a limited number of field-based studies. Our research addresses
this knowledge gap around the southwestern shore of Great Slave Lake. Our goal is to reconstruct the ice flow chronology of this region and trace the dominant provenance of subglacial tills to improve our understanding of past ice-sheet configuration
and subglacial sedimentary processes. Relative ice-flow chronology is established using glacial landforms, outcrop-scale ice-flow indicators, as well as till stratigraphic and provenance analyses. Outcrop-scale indicators show a shift in ice flow
direction from an oldest southwestern (230°) flow, to a western (250°) flow, to a final northwestern (305°) flow. Lodged boulders and till clast fabrics from till stratigraphic sections across the study area are broadly consistent with the clockwise
ice flow shift. Indicators of northeast provenance include Canadian Shield clasts and certain major oxides (e.g. Cr2O3, Fe2O3) that are considered enriched in northeast bedrock sources relative to local bedrock. At least one till unit is associated
with the southwest ice-flow phase based on landforms, till clast macro-fabrics, and a discernible northeast provenance (Canadian Shield) signature. Younger tills were deposited during the clockwise ice flow shift. These tills are located in lower
elevation areas of the study area and their composition has an increased Paleozoic (local bedrock) signature, but also includes input from Paleozoic strata to the east. The integrated ice flow records from this study, along with previous studies from
the Pine Point mining district, show compelling evidence for major shifts in ice sheet configuration and flow dynamics, as well as related subglacial conditions (e.g. changes in subglacial sediment entrainment) during the last glaciation. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Il s'agit d'une présentation d'un projet de recherche à la maîtrise financé par le GEM sur la distribution et la géochimie des tills qui se
trouvent à la surface dans la partie sud-ouest des TNO. Cela aidera à comprendre les diverses influences que les écoulements glaciaires du passé ont eu sur le paysage, afin de faciliter l'exploration minérale future dans la région. |
| GEOSCAN ID | 328269 |
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