GEOSCAN, résultats de la recherche


TitreDispersal trains in eskers
AuteurCummings, D I; Russell, H A J; Sharpe, D R
SourceProceedings of the GAC - MAC - SEG - SGA Join Annual Meeting, 2011; L'Association géologique du Canada-L'Association minéralogique du Canada, Réunion annuelle conjointe, Recueil des résumés 2011.
LiensOnline - En ligne
Séries alt.Secteur des sciences de la Terre, Contribution externe 20100443
ÉditeurAssociation géologique du Canada
RéunionGAC/MAC/SEG/SGA annual meeting; Ottawa; CA; mai 25-27, 2011
Documentpublication en série
Mediapapier; en ligne; numérique
Sujetseskers; dépôts glaciaires; exploration de dépôts glaciaires; éléments d'indice; tills; dispersion des sédiments; prospection minière; géologie économique; géologie générale; géologie des dépôts meubles/géomorphologie
ProgrammeDiamands, GEM : La géocartographie de l'énergie et des minéraux
Résumé(disponible en anglais seulement)
Eskers are commonly sampled for indicator minerals during drift prospecting campaigns on the Precambrian Shield. Esker sampling is a proven method: it has led to the discovery of several kimberlites, including the Lac de Gras kimberlite field, home to Canada's first diamond mine. Although commonly associated with diamond exploration, it can be used to locate any mineral deposit type that yields a characteristic suite of indicator minerals (e.g., Ni-Cu-PGE deposits). However, a literature review reveals that indicator-mineral dispersal in esker sedimentary systems is a poorly understood phenomenon. Beyond basic concepts established almost a century ago 'most eskers are derived from till and contain dispersal trains that extend roughly parallel to those in the till' exploration companies lacking their own proprietary knowledge are left with little basis for understanding how to sample eskers or interpret esker data. What parts of eskers should be targeted when sampling for indicator minerals? How long are indicator-mineral dispersal trains in eskers, typically? Tens of meters? Tens of kilometers? Hundreds of kilometers? What about pebble dispersal trains? Are they typically shorter? Based on the literature review and on recently collected data from the Keewatin, and drawing insights from a broader body of literature on modern glaciers, lab experiments, and gravel-bed streams, a preliminary conceptual framework for esker sedimentary systems is established to address these issues. A research strategy is then outlined, one whose objective is to fill knowledge gaps and, in doing so, improve the effectiveness of mineral exploration in glaciated terrain.