| Titre | Toward a new glacial geology framework supporting geoscience applications in the southwestern Great Slave Lake area |
| |
| Auteur | Hagedorn, G W; Ross, M; Paulen, R C ; Smith, I R; Neudorf, C M; Gingerich, T;
Lian, O B |
| Source | 47th Annual Yellowknife Geoscience Forum, abstracts; par Gervais, S D; Irwin, D; Terlaky, V; Northwest Territories Geological Survey, Yellowknife Geoscience Forum Abstract and Summary Volume 2019, 2019
p. 107-108  Accès ouvert |
| Liens | Online - En ligne (complete volume -
volume complet, PDF, 6.60 MB)
|
| Image |  |
| Année | 2019 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20200046 |
| Éditeur | Commission géologique des Territoires du Nord-Ouest |
| Réunion | 47th Annual Yellowknife Geoscience Forum; Yellowknife, NT; CA; Novembre 19-21, 2019 |
| Document | publication en série |
| Lang. | anglais |
| Media | en ligne; numérique |
| Formats | pdf |
| Province | Territoires du Nord-Ouest |
| SNRC | 85C; 85F |
| Région | Grand lac des Esclaves; Tathlina Lake; Cameron HIlls; Fleuve Mackenzie; Hay River; Kakisa River; Kakisa Lake |
| Lat/Long OENS | -118.0000 -116.0000 62.0000 60.0000 |
| Sujets | antecedents glaciaires; glaciation; écoulement glaciaire; déglaciation; établissement de modèles; sediments; dunes; crêtes de plage; dépôts glaciaires; tills; moraines; graviers; elements glaciaires;
stries glaciaires; cannelures glaciaires; topographie glaciaire; clastes; origine; analyses texturales; structure du till; lithologie des galets; carbonate; échantillons de till; dépôts de glissement de terrain; glissements; Calotte glaciaire
Laurentide; Lac glaciaire de McConnell; Bouclier Canadien; Cordillère canadienne; directions d'écoulement glaciaire; sédiments éoliens; géologie des dépôts meubles/géomorphologie; stratigraphie; géochronologie; Nature et environnement; Sciences et
technologie; Phanérozoïque; Cénozoïque; Quaternaire; Mésozoïque; Crétacé; 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 | 2019 11 01 |
| Résumé | (disponible en anglais seulement)
A better understanding of the Northwest Territories surficial geology is important for addressing topics such as natural resource extraction, permafrost change,
infrastructure development, and land use management. The area surrounding southwestern Great Slave Lake (NTS 85C/85F) is one such region requiring greater surficial geological understanding. This region includes several towns and communities,
important infrastructure (highways, railroads), is within the discontinuous permafrost zone, and is considered to host a significant mineral resource potential. Our research aims to improve understanding of Laurentide Ice Sheet (LIS) dynamics and
evolution of glacial Lake McConnell, as well as the nature and distribution of surficial sediments, regional stratigraphy, and permafrost landforms.
Previous interpretations of ice-flow in the area indicated a generalized westward trajectory. New
ice-flow erosional indicators (n=66) provide evidence for an oldest southwest flow (230°), followed by an intermediate westward flow (280°), and a later northwestward flow (305°). Stratigraphic observations and sediment properties (n=160) indicate
three distinct till units. The lowest (oldest) till observed is a grey diamicton sourced mainly from local Paleozoic sedimentary rocks. A southwestward ice flow direction is interpreted for this unit based on clast fabrics and is consistent with the
oldest erosional ice-flow indicators. The lower till is overlain by a brown diamicton containing a higher proportion of far-travelled Canadian Shield clasts. This brown till contains lodged, elongate boulders with parallel striations on their upper
surface and clast fabrics indicating a west to northwestward ice-flow direction, broadly consistent with the interpreted intermediate ice-flow phase. The third till, with a dominant local bedrock provenance, forms a discontinuous unit at surface
across the study area. Although no clear stratigraphic constraints were found, the third till appears to be related to the final ice-flow phase. Streamlined landforms, moraines, and other sediment-landform assemblages previously understudied in the
region have now been mapped and analyzed in greater detail and further supporting LIS dynamics interpretations and deglacial history.
Minimum deglacial age estimates are better constrained through optical dating of medium-sand deposits in a
well-developed raised beach (n=2) and relict aeolian dunes (n=7). Optical dating results indicate distinct shoreline development associated with the retreat of glacial Lake McConnell, and phases of dune development following lake drainage.
Interpretation of local LIS dynamics and ice-margin retreat enhances our understanding of the western LIS and will inform practical applications of surficial geology in the southwestern Great Slave Lake area. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Présentation de thèse de maîtrise, financée par l'activité GEM2 South Mackenzie Surficial. Cette présentation par affiches résumera la
cartographie superficielle, la stratigraphie glaciaire et la chronologie glaciaire/déglaciale. |
| GEOSCAN ID | 326073 |
|
|