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TitleIdentification, classification, and distribution of retrogressive creeping slumps, Lac de Gras region, Northwest Territories
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AuthorMcWade, T L; Morse, P D; Gruber, S; Wolfe, S A
SourceGeological Survey of Canada, Open File 8197, 2017, 120 pages, https://doi.org/10.4095/304245
Year2017
PublisherNatural Resources Canada
Documentopen file
Lang.English
Mediaon-line; digital
File formatpdf
ProvinceNorthwest Territories
NTS76C/11; 76C/12; 76C/13; 76C/14; 76D/09; 76D/10; 76D/15; 76D/16
AreaLac de Gras
Lat/Long WENS-110.8333 -109.1667 65.0000 64.5000
Subjectssurficial geology/geomorphology; geophysics; permafrost; periglacial features; landforms; creep; slumps; remote sensing; photogrammetric techniques; airphoto interpretation; geophysical interpretations; glacial deposits; tills; hummocks; boulders; morphology; slope development; ground ice; massive ice; cold regions research; troughs; mass wasting; deglaciation; modelling; Ekati Diamond Mine; retrogressive creeping slumps; LiDAR; digital elevation models; hillslope processes; landform evolution; risk to infrastructure; Phanerozoic; Cenozoic; Quaternary
Illustrationslocation maps; geophysical images; photographs; aerial photographs; geoscientific sketch maps; schematic cross-sections; profiles; histograms; plots; rose diagrams; tables
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Location
 
Natural Resources Canada Library - Ottawa (Earth Sciences)
 
ProgramPermafrost, Climate Change Geoscience
Released2017 07 27
AbstractThe purpose of this Open File is to identify and map a locally common yet unclassified set of landforms first observed during summer 2015 fieldwork in continuous permafrost of the Lac de Gras region of Northwest Territories. Quantitative and qualitative data extracted from 152 landforms using aerial photographs and LiDAR data were used to describe and quantify the general form. The landforms exhibit a continuous depression situated several meters behind and parallel to a steep, curvilinear hillslopes, beneath which is a gentle footslope. The hillslopes appear to incise the margins of till blanket deposits, and the footslopes are covered with boulders. According to morphological characteristics, the mapped landforms were divided into three classes, interpreted as early, late, and final stages of an apparent time-transgressive landform evolution. Based on extracted morphological characteristics and field observations the landforms have been tentatively termed retrogressive creeping slumps.
Summary(Plain Language Summary, not published)
A locally common yet unclassified set of landforms were identified in continuous permafrost of the Lac de Gras region of Northwest Territories. They form a continuous depression situated several meters set back from and parallel to the top of a steep hillslope, the base of which is a gentle footslope. The hillslopes are located at the margins of deposits that are assumed to be till blanket, and the footslopes are covered with boulders. Quantitative and qualitative data for 152 individual landforms extracted from aerial photographs and LiDAR data were used to describe and quantify a general form. It is hypothesized that the landforms result from complex mass-wasting and that the morphology is linked to changing ground ice and active-layer conditions.
GEOSCAN ID304245