| Title | Relict glacial terrains in west central Keewatin Sector, Laurentide Ice Sheet, Northwest Territories and Nunavut |
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| Author | Campbell, J; Godbout, P -M; McMartin, I ; Normandeau, P |
| Source | GAC®-MAC 2021, London, Canada: Exploring Geosciences Through Time and Space/GAC®-MAC 2021, London, Canada : Explorer les géosciences à travers le temps et l'espace; Geological Association of
Canada-Mineralogical Association of Canada, Joint Annual Meeting, Abstracts Volume vol. 44, 2021 p. 57 
Open Access |
| Links | Online - En ligne (complete
volume - volume complet, PDF, 2.45 MB)
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| Image |  |
| Year | 2021 |
| Alt Series | Natural Resources Canada, Contribution Series 20200639 |
| Publisher | Geological Association of Canada |
| Meeting | GAC-MAC 2021: Geological Association of Canada-Mineralogical Association of Canada Joint Annual Meeting 2021; London, ON; CA; November 1-5, 2021 |
| Document | serial |
| Lang. | English |
| Media | digital; on-line |
| File format | pdf |
| Province | Northwest Territories; Nunavut |
| NTS | 54L/10; 54L/11; 54L/14; 54L/15; 54L/16 |
| Area | Aylmer Lake; Thelon Wildlife Sanctuary |
| Lat/Long WENS | -96.9167 -93.7500 59.6667 58.8333 |
| Subjects | surficial geology/geomorphology; geochemistry; economic geology; Science and Technology; Nature and Environment; glacial deposits; glacial landforms; glacial features; lineations; eskers; glacial
striations; tills; glacial history; glaciation; ice flow; deglaciation; field work; weathering; lithology; depositional environment; thermal analyses; topography; frost action; glacial erosion; mineral exploration; Laurentide Ice Sheet; Keewatin
Sector; Exeter Lake Esker System; ice-flow directions; till veneer; Phanerozoic; Cenozoic; Quaternary |
| Program | GEM2: Geo-mapping for Energy and Minerals Rae Province, Synthesis of glacial history |
| Released | 2021 11 01 |
| Abstract | The Glacial Map of Canada portrays several regions devoid of glacial lineations and eskers, or with discordant ice-flow indicators in the Keewatin Sector of the Laurentide Ice Sheet (LIS). Such regions
have been theorized to reflect relict terrains preserved under cold-based ice during all or part of the last glaciation cycle. Recent field-based work in other regions of mainland Nunavut has confirmed the presence of relict/cold-based terrains. One
of the largest proposed relict landscapes lies in the largely unmapped west-central region of the Keewatin Sector. To ascertain the nature of this terrain and the adjacent glacial landscapes, targeted surficial geological studies were conducted in an
area between Aylmer Lake, Northwest Territories (NWT) and the western edge of the Thelon Wildlife Sanctuary in the NWT and Nunavut. New field-based observations and striation measurements were combined with till composition data to reveal the complex
glacial history of the study area. Spatial variability in the region's geomorphology, and surface material composition, thickness and degree of weathering, are the result of changes in substrate lithology, depositional environments, basal thermal
conditions (warm-based to cold-based) and paleo-ice flow dynamics. Much of the landscape is warm-based to deglacial warm-based, dominated by west to northwest-trending streamlined and/or thicker drift terrains. However, the landscape of the central
part of the study area is bedrock-controlled; dominated by low relief, weathered and frost-shattered outcrops, and block fields, consistent with relict terrains preserved under non-erosive, cold-based ice conditions. Relative terrestrial cosmogenic
nuclide abundances confirm that this central region is a relict landscape that has been preserved under cold-based conditions during the last glacial cycle. Small patches of warm-based ice terrains with very thin, discontinuous veneers of till are
interspersed throughout this central area. Rare glacially sculpted and polished outcrops record older south-southwest flow(s). The south margin of the study area is bounded by the west-northwest trending Exeter Lake esker system, a major deglacial
feature. The results of this research have implications for mineral exploration in this under-explored region and will inform paleo-ice dynamic modelling of the LIS. |
| Summary | (Plain Language Summary, not published)
This presentation for a National conference will discuss the results of new glacial landscape mapping in the NWT-Kitikmeot (NU) region (western Keewatin)
as part of the GEM-2 Rae Synthesis of Glacial History and Dynamics Activity. The talk will present the results of the latest research regarding the identification of relict terrain that was not modified during the last glaciation. This research was
undertaken to provide new geological knowledge on the glacial history of the western Keewatin region and to help understand glacial transport across various glacial landscapes of northern Canada. The findings will support informed decision making for
resource exploration and land use management. |
| GEOSCAN ID | 327910 |
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