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TitleMineral dispersal trains as products of hard-bedded ice streams in northern Canada
 
AuthorPaulen, RORCID logo; Stokes, C; McClenaghan, B
SourceINQUA 2019, Dublin, Ireland: 20th Congress of the International Union for Quaternary Research (INQUA); P-4840, 2019 p. 1 Open Access logo Open Access
LinksOnline - En ligne
Image
Year2019
Alt SeriesNatural Resources Canada, Contribution Series 20180362
PublisherInternational Union for Quaternary Research
MeetingINQUA 2019, Dublin, Ireland: 20th Congress of the International Union for Quaternary Research (INQUA); Dublin; IE; July 25-31, 2019
DocumentWeb site
Lang.English
Mediaon-line; digital
File formathtml; pdf
ProvinceNunavut; Northwest Territories; Quebec; Newfoundland and Labrador
NTS15; 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
AreaLabrador
Lat/Long WENS-120.0000 -64.0000 72.0000 56.0000
Subjectssurficial geology/geomorphology; economic geology; mineralogy; geochemistry; geophysics; Science and Technology; Nature and Environment; glacial history; ice flow; glacial deposits; tills; glacial landforms; sediment dispersal; clasts; provenance; geophysical surveys; radiometric surveys; gamma-ray surveys, airborne; mineral exploration; mineral deposits; carbonates; kimberlites; Laurentide Ice Sheet; Dubawnt Dispersal Train; Strange Lake Dispersal Train; Labrador Dome; Tremblay Corridor; Gulf of Boothia Ice Stream; Foxe Dome; ice streams; dispersal trains; ice-flow directions; Phanerozoic; Cenozoic; Quaternary; Paleozoic; Precambrian
ProgramGEM2: Geo-mapping for Energy and Minerals Mackenzie Corridor, Southern Mackenzie Surficial Mapping
Released2019 07 01
AbstractThe 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.
Summary(Plain Language Summary, not published)
Synthesis of ice stream and mineral dispersal train research conducted in GEM-1 and GEM-2. This is an international conference to present new research to scientific peers.
GEOSCAN ID313527

 
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