| Title | Lithalsa distribution, morphology and landscape associations in the Great Slave Lowlands, Northwest Territories |
| Download | Downloads |
| |
| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Stevens, C W; Wolfe, S A ; Gaanderse, A J R |
| Source | Geological Survey of Canada, Open File 7255, 2012, 41 pages, https://doi.org/10.4095/292115  Open Access |
| Year | 2012 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Maps | 1 map |
| Map Info. | geological, lithalsa distribution, 1:166,666 |
| Media | on-line; digital |
| Related | This publication is related to Distributions of degraded and
intact lithalsas, North Slave region, Northwest Territories |
| File format | readme
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| File format | pdf; shp; rtf |
| Province | Northwest Territories |
| NTS | 85J/10; 85J/11; 85J/12; 85J/13; 85J/14; 85J/15 |
| Area | Yellowknife |
| Lat/Long WENS | -116.0833 -114.4167 62.8833 62.3333 |
| Subjects | engineering geology; surficial geology/geomorphology; Nature and Environment; permafrost; ground ice; freezing ground; glaciation; glacial deposits; vegetation; remote sensing; Great Slave Lowlands;
LiDAR; Quaternary; Cenozoic |
| Illustrations | location maps; aerial photographs; tables; photographs; graphs |
| Program | Climate Change Geoscience |
| Released | 2012 12 05 |
| Abstract | The 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 ID | 292115 |
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