| Title | Surficial geology and Holocene shoreline evolution near Whitebeach Point, Great Slave Lake, Northwest Territories |
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| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | O'Neill, H B ;
Wolfe, S A; Kerr, D E |
| Source | Geological Survey of Canada, Current Research (Online) 2019-3, 2019, 15 pages, https://doi.org/10.4095/314638  Open Access |
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| Year | 2019 |
| Publisher | Natural Resources Canada |
| Document | serial |
| Lang. | English |
| Media | on-line; digital |
| File format | pdf (Adobe® Reader®) |
| Province | Northwest Territories |
| NTS | 85J/06 |
| Area | Whitebeach Point; Great Slave Lake |
| Lat/Long WENS | -115.3333 -115.2333 62.4667 62.4000 |
| Subjects | surficial geology/geomorphology; geophysics; geochronology; hydrogeology; economic geology; Holocene; glacial lakes; surface waters; lakes; sediments; beach sands; dunes; beach ridges; organic deposits;
peatlands; glacial history; deglaciation; depositional history; shoreline changes; water levels; postglacial emergence; permafrost; ground ice; vegetation; hydrologic environment; geophysical surveys; radiometric dating; radiocarbon dating; mineral
deposits; mineral potential; sand, commodity; fracturing sands; silica sands; remote sensing; photogrammetric surveys; groundwater; groundwater flow; sand wedges; Glacial Lake McConnell; Ancestral Great Slave Lake; glaciolacustrine beach sediments;
eolian sediments; Forests; elevations; colluvial and mass-wasting deposits; alluvial sediments; lacustrine sediments; lacustrine beach sediments; lacustrine littoral sediments; Phanerozoic; Cenozoic; Quaternary |
| Illustrations | location maps; geoscientific sketch maps; profiles; tables; time series; photographs |
| Program | GEM2: Geo-mapping for Energy and Minerals Mackenzie Corridor, North Bear Surficial Mapping |
| Released | 2019 09 10 |
| Abstract | Deposits of well sorted silica-rich beach sands occur along the western shore of Great Slave Lake around Whitebeach Point, Northwest Territories. Much of these deposits were windblown and redeposited
following Holocene regression of glacial Lake McConnell and ancestral Great Slave Lake. Eolian deposits include active and stabilized sand sheets, transverse dunes, and localized blowouts. High-resolution lidar and optical imagery, combined with
optical and radiocarbon dating, were used to derive a lake-level regression curve for the area, map the surficial geology and geomorphology, and reconstruct Holocene shorelines and landscape development. Lake water level was near the base of a
limestone escarpment in the study area ca. 9.5 ka, about 60 m above the present lake level, and subsequently declined at a rate of about 2.3 mm a-1 from ca. 7.0 ka onward. Lake-level regression was accompanied by beach- and eolian-sand deposition in
the form of incipient foredunes, primarily within a protected embayment. Permafrost occurs beneath land surfaces with thick (>30 cm) organic cover, including peatlands and densely forested areas, and likely affects the groundwater hydrology in the
area. Permafrost is absent under sparsely vegetated eolian sand surfaces. |
| Summary | (Plain Language Summary, not published)
Deposits of well-sorted beach sands occur along the western shore of Great Slave Lake around Whitebeach Point, NT. These deposits were deposited by wind
after glacial Lake McConnell receded. Windblown deposits include active and stabilized sand sheets and dunes. We mapped the surficial geology and geomorphology and reconstructed Holocene shorelines and landscape development in the region. Lake water
level was near the base of a limestone escarpment in the study area about 9,500 years ago, about 60 m above the present lake level, and then declined at a rate of ~2.3 mm per year from about 7,000 years ago onward. Lake-level regression was
accompanied by beach and windblown sand deposition as parallel sand dunes within a protected embayment. Permafrost occurs beneath land surfaces with thicker organic cover, including peatlands and densely forested areas, and likely affects the
groundwater hydrology in the area. Permafrost is absent under sparsely vegetated sand surfaces. |
| GEOSCAN ID | 314638 |
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