GEOSCAN, résultats de la recherche

Menu GEOSCAN


TitreStudy of glacial flows and associated sediments: the case of Amaruq, Nunavut
AuteurBoulianne-Verschelden, N; de Bronac de Vazelhes, V; McMartin, I; Beaudoin, G; Côté-Mantha, O; Simard, M
SourceGAC-MAC 2017; Association géologique du Canada-Association minéralogique du Canada, Réunion annuelle, Programme et résumés vol. 40, 2017 p. 38
LiensOnline - En ligne
Année2017
Séries alt.Secteur des sciences de la Terre, Contribution externe 20160447
ÉditeurAssociation géologique du Canada
RéunionGeological Association of Canada-Mineralogical Association of Canada Joint Annual Meeting 2017; Kingston, ON; CA; mai 14-18, 2017
Documentpublication en série
Lang.anglais
Mediapapier; en ligne; numérique
Formatspdf
ProvinceNunavut
Sujetslevés géologiques; distribution minérale; prospection minière; nappes glaciaires; mouvement de la glace; écoulement glaciaire; dispersion des sédiments; dépôts de till
ProgrammeChantrey-Thelon de la province de Rae, GEM2 : La géocartographie de l'énergie et des minéraux
Résumé(disponible en anglais seulement)
The Amaruq project is located in Nunavut 60 km northwest of the currently operating Meadowbank gold mine. This region has a significant mineral potential but the basement rock is largely covered by till, thus furthering our understanding of glacial dispersal processes is essential for efficient exploration in the area. This study is on the understanding of the ice-flow history and surficial geology mapping of the Quaternary deposits at regional (1: 50,000) and detailed (1: 10,000) scales, both centered on the gold deposits at Amaruq. The study area is located about 100 km northwest of the last position of the Keewatin Ice Divide.
During the last glaciation, the Laurentide Ice Sheet covered the study area until the ice disappeared approximately 6,000-7,000 14C years ago. As a result, the area is extensively covered by various types of glacial deposits. The predominant surficial deposits are bouldery sandy till veneers, commonly forming small ridges perpendicular to ice flow, thick silty till blankets in streamlined landforms or plains, and five glaciofluvial systems containing esker ridges, hummocks, diamictons, kames and outwash plains. The thick silty till blankets appear to cover the sandy till veneers.
Previous reconnaissance-scale mapping indicates a main north-northwest regional ice-flow direction. In the study area, four sets of ice-flow directions were recognized based on the detailed mapping of striations, grooves and roches moutonnées. The oldest, oriented towards the NNW (N345°), is the dominant direction and is responsible for most of the glacial moulding of the landforms. The second and third ones are oriented respectively at N325° and N308° and did not have a significant influence on the orientation of the landforms. The fourth ice-flow set is found only locally along glaciofluvial systems and indicates late ice flows towards esker ridges.
A preliminary pebble count was done by ODM Laboratories on 10-kg till samples collected from frost boils. The results show that the sandy till veneers material has a major local component derived from the underlying bedrock. The bouldery sandy till veneer shows a sharp change in pebble composition across the underlying lithological boundaries in bedrock. The lithological package hosting the Amaruq mineralized zones is dominated by ultramafic to intermediate volcanic and sedimentary rocks, whereas the dominant lithologies up-ice of mineralization are essentially of granitic composition. The pebbles of the thick silty till blankets over and down-ice of the mineralized zones are granite-dominated even if the lithologies beneath are of the volcanic and sedimentary origin.
Résumé(Résumé en langage clair et simple, non publié)
Cette affiche présente un aperçu des travaux sur le terrain menés en 2016 sur le projet d'exploration aurifère Amaruq au Nunavut central continental sur la géologie de surface des zones minéralisées. L'interprétation de l'histoire glaciaire et la cartographie des dépôts de surface ainsi qu'un échantillonnage ciblé du till et de la roche minéralisée font partie de deux projets de thèse de maîtrise pour développer des méthodes de prospection glacio-sédimentaire pour l'or dans des régions pergélisolées. La Commission géologique du Canada participe conjointement à superviser l'étudiant au sein de la Chaire de recherche industrielle CRSNG - Agnico Eagle en exploration minérale à l'Université Laval. L'étude fait partie de l'activité GEM-2 Thelon-Chantrey du Projet Rae et les résultats permettront d'améliorer les méthodes d'exploration minérale en terrain glaciaire.
GEOSCAN ID300221