| Titre | Mineral dispersal trains as products of hard-bedded ice streams in northern Canada |
| |
| Auteur | Paulen, R ;
Stokes, C; McClenaghan, B |
| Source | INQUA 2019, Dublin, Ireland: 20th Congress of the International Union for Quaternary Research (INQUA); P-4840, 2019 p. 1  Accès ouvert |
| Liens | Online - En ligne
|
| Image |  |
| Année | 2019 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20180362 |
| 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 | Nunavut; Territoires du Nord-Ouest; Québec; Terre-Neuve-et-Labrador |
| SNRC | 15; 16; 23; 24; 25; 26; 27; 33; 34; 35; 36; 37; 45; 46; 47; 55; 56; 57; 65; 66; 67; 75; 76; 77; 85; 86; 87 |
| Région | Labrador |
| Lat/Long OENS | -120.0000 -64.0000 72.0000 56.0000 |
| Sujets | antecedents glaciaires; écoulement glaciaire; dépôts glaciaires; tills; topographie glaciaire; dispersion des sédiments; clastes; origine; levés géophysiques; levés radiométriques; levés par rayons gamma
aériens; prospection minière; gisements minéraux; carbonates; kimberlites; Calotte glaciaire Laurentide; Dôme de Labrador ; Dôme de Foxe ; courants glaciaires; traînées de dispersion; directions d'écoulement glaciaire; géologie des dépôts
meubles/géomorphologie; géologie économique; minéralogie; géochimie; géophysique; Sciences et technologie; Nature et environnement; 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 | 2019 07 01 |
| Résumé | (disponible en anglais seulement)
The identification of glacial dispersal landforms and sedimentary deposits formed by fast-flowing glaciers was important to the earliest recognition of
palaeo-ice streams of the Laurentide Ice Sheet in the 1970 and 1980s. The spectacular continental-scale Dubawnt dispersal train in northern Canada was one of the first to be identified as the product of a high glacial flow rate. Subsequently,
dispersal plumes of Paleozoic carbonate rocks imprinted on Precambrian Canadian Shield terrain in northern Canada were interpreted to be products of ice streams.
Smaller glacial dispersal trains emanating from point sources within larger
palaeo-ice stream trunk flows have also been identified. The Strange Lake glacial dispersal train in northern Quebec and Labrador, is a remarkably linear ribbon defined by till geochemistry and airborne gamma-ray data that extends >60 km down-ice
(northeast) from a mineralized rare earth element-rich peralkaline intrusion. This dispersal train formed within one of several ice streams that operated over a hard bed near the center of the Labrador Dome of the Laurentide Ice Sheet. Further north,
a kimberlite indicator mineral-rich dispersal train (referred to as the Tremblay Corridor) extends 65 km down-ice (northwest) from a cluster of kimberlite intrusions on northern Melville Peninsula, Nunavut. This glacial dispersal train was also
formed over a hard bed by the Gulf of Boothia Ice Stream, which originated from the Foxe Dome of the Laurentide Ice Sheet.
The geomorphic imprint of ice streams over hard-bed, higher relief areas tends to be less obvious because of thinner till
cover and an absence of diagnostic geomorphic features such as shear margin moraines. Despite the relatively thin till cover in the Strange Lake, Labrador area, and on the northern Melville Peninsula, the extremely high concentrations of mineralized
(exotic) debris within the till 10s of kilometres down-ice from their sources is quite remarkable. Typically, under normal ice flow conditions in areas of hard-beds on the Canadian Shield, dispersal trains formed by erosive ice are diluted over
relatively short distances (<5 km) down-ice. The long (10s of km) dispersal trains of till with distinct chemical and/or mineralogical compositions, coupled with obvious erosive/depositional corridors of streamlined landforms, provide a means of
identifying hard-bedded ice streams elsewhere in northern Canada. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Synthèse de la recherche sur les courants de glace et les trains de dispersion des minéraux dans GEM-1 et GEM-2. Il s'agit d'une conférence
internationale destinée à présenter les nouvelles recherches à des pairs scientifiques. |
| GEOSCAN ID | 313527 |
|
|