GEOSCAN Search Results: Fastlink

GEOSCAN Menu


TitleLithalsa distribution, morphology and landscape associations in the Great Slave Lowlands, Northwest Territories
DownloadDownloads
AuthorStevens, C W; Wolfe, S A; Gaanderse, A J R
SourceGeological Survey of Canada, Open File 7255, 2012, 41 pages, https://doi.org/10.4095/292115
Year2012
PublisherNatural Resources Canada
Documentopen file
Lang.English
Maps1 map
Map Info.geological, lithalsa distribution, 1:166,666
Mediaon-line; digital
File formatreadme
File formatpdf; shp; rtf
ProvinceNorthwest Territories
NTS85J/10; 85J/11; 85J/12; 85J/13; 85J/14; 85J/15
AreaYellowknife
Lat/Long WENS-116.0833 -114.4167 62.8833 62.3333
Subjectsengineering geology; surficial geology/geomorphology; permafrost; ground ice; freezing ground; glaciation; glacial deposits; vegetation; remote sensing; Great Slave Lowlands; LiDAR; Lithalsa; Quaternary; Cenozoic
Illustrationslocation maps; aerial photographs; tables; photographs; graphs
Viewing
Location
 
Natural Resources Canada Library - Ottawa (Earth Sciences)
 
ProgramLand-based Infrastructure, Climate Change Geoscience
Released2012 12 05
AbstractThe distribution of ice-rich terrain is an important geotechnical consideration for the engineering of northern infrastructure. Lithalsas represent one form of ice-rich terrain that can be identified on the basis of surface geomorphology and cryostratigraphy. A total of 1,777 ice-rich lithalsas were mapped over 3,680 km2 using monochromatic stereo-pair airphotos, across the Great Slave Lowlands and Uplands, NWT, Canada. Boreholes indicate lithalsas in this region consist of ice-rich silt and clay, with segregated ice lenses up to 10 cm thick. Three distinct morphologies are recognized from LiDAR bare-earth DEMs including; (i) circular, (ii) linear and (iii) crescentic plan-view shapes, which exhibit hill-like or ridge-like forms up to 8 m in height and more than 100 m in width. The linear relationship between lithalsa height and width indicates that 1 cm of vertical growth may be accompanied by 15 cm of lateral growth at the peripheral edges. Lithalsa distribution is skewed towards lower elevations, with 97.7% located within the Great Slave Lowlands. These features predominately occur adjacent to water bodies and follow the regional distribution of frost susceptible glaciolacustrine silt and clay. Landscape associations suggest lithalsa formation is controlled by sedimentological, thermal and hydrological conditions. This Open File reports the first account of lithalsas within this region.
GEOSCAN ID292115