| Titre | Glacial stratigraphy and till micromorphology at Pine Point, southern Northwest Territories, Canada |
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| Auteur | Sapera, J; Menzies, J; Paulen, R |
| Source | INQUA 2019, Dublin, Ireland: 20th Congress of the International Union for Quaternary Research (INQUA); P-1863, 2019 p. 1  Accès ouvert |
| Liens | Online - En ligne
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| Image |  |
| Année | 2019 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20180394 |
| Éditeur | International Union for Quaternary Research |
| Réunion | INQUA 2019, Dublin, Ireland: 20th Congress of the International Union for Quaternary Research (INQUA); Dublin; IE; juillet 25-31, 2019 |
| Document | site Web |
| Lang. | anglais |
| Media | en ligne; numérique |
| Formats | html; pdf |
| Province | Territoires du Nord-Ouest |
| SNRC | 85B/09; 85B/10; 85B/11; 85B/14; 85B/15; 85B/16 |
| Région | Pine Point; Grand lac des Esclaves |
| Lat/Long OENS | -115.5000 -114.0000 61.0000 60.5000 |
| Sujets | dépôts glaciaires; tills; stratigraphie du till; milieu sédimentaire; antecedents de sedimentation; déformation; marges glaciaires; clastes; analyses texturales; géochimie du till; prospection minière;
méthodes d'exploration; mines; mines à ciel ouvert; Calotte glaciaire Laurentide; géologie des dépôts meubles/géomorphologie; stratigraphie; sédimentologie; géochimie; minéralogie; géologie économique; Nature et environnement; Sciences et
technologie |
| Programme | GEM2 : La géocartographie de l'énergie et des minéraux Cartographie des dépôts meubles du sud du Mackenzie du corridor de Mackenzie |
| Diffusé | 2019 07 01 |
| Résumé | (disponible en anglais seulement)
The Pine Point Mississippi Valley-type (MVT) Pb-Zn mining district extends 50 km along an east-west trend south of Great Slave Lake, Northwest Territories, in
northern Canada. The district contains 50 open pits that expose glacial sediments, in some cases more than 20 m thick, providing a unique opportunity for glacial stratigraphic analyses. A detailed stratigraphic study is being undertaken on a thick
(>20 m) basal till sequence at open pit M-52 in the north-central part of the district. The goal of the research is to augment the existing knowledge of the regional Quaternary stratigraphy and to investigate the mechanics of till
deposition/emplacement throughout the continuous till sequence to better understand the glacial dynamics for the western margin of the Laurentide Ice Sheet. Additionally, the glacial stratigraphy at pit M-52 will be correlated with the previous
research conducted within the mining district, regionally with Quaternary sections exposed along the Mackenzie River to the west, and extensionally with seismic shothole and diamond drill hole stratigraphic databases. Till samples were collected for
macro- and micro-sedimentological studies.
Macrosedimentology studies incorporate glacial stratigraphy, sedimentology, clast fabrics, geomorphology, and laboratory analyses for matrix geochemistry and indicator minerals. The walls of pit M-52
expose two visibly distinct tills, a grey till exposed at the base of the section and an upper brown till. When a complete vertical section was cleared and examined, the contact between the two tills was indiscernible and suspected to be gradational
over several metres. The upper brown till could reflect surface oxidation of the lower grey till. However, based on previous research conducted in the region, it is unlikely that there is only a single till exposed in the pit walls. The suspected
gradational contact is likely a product of extensive glacial inheritance and mixing as glacial dynamics shifted during till accretion. Clast fabrics were measured in the section and revealed that the grey till close to the bedrock surface reflects SW
ice flow, the middle of the section in the gradational zone reflects NW flow, and the brown till near the top displays evidence of NW ice flow.
Detailed glacial microsedimentological data analyses for 38 samples, collected from the two till
units, will be used to determine the stress conditions and rheological environments during till emplacement/ deposition. The use of micromorphology in this study is as a primary tool for the analysis of these subglacial sediments, providing far
greater detail on the depositional and deformation histories recorded by these sediments than previously obtained from macroscale studies. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Il s'agit d'une recherche de maîtrise en sciences financée par GEM-2 présentée à une conférence internationale dans le cadre d'une session
spéciale sur la micromorphologie glaciaire. |
| GEOSCAN ID | 313618 |
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