| Title | The Cameron Hills ice streams of southern Northwest Territories, Canada: a closer look |
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| Author | Paulen, R ;
Menzies, J; Phillips, E; Stokes, C; Smith, R |
| Source | INQUA 2019: 20th Congress of the International Union for Quaternary Research, programme
; O-0127, 2019 p. 1  Open Access |
| Links | Online - En ligne
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| Image |  |
| Year | 2019 |
| Alt Series | Natural Resources Canada, Contribution Series 20180373 |
| Publisher | International Union for Quaternary Research |
| Meeting | INQUA 2019 - 20th Congress of the International Union for Quaternary Research (INQUA); Dublin; IE; July 25-31, 2019 |
| Document | Web site |
| Lang. | English |
| Media | on-line; digital |
| File format | html; pdf (Adobe® Reader®) |
| Province | Northwest Territories |
| NTS | 85C; 85D |
| Area | Cameron Hills |
| Lat/Long WENS | -120.0000 -116.0000 61.0000 60.0000 |
| Subjects | surficial geology/geomorphology; sedimentology; Nature and Environment; Science and Technology; glacial history; ice flow; glacial features; lineations; glacial landforms; glacial deposits; tills;
depositional environment; glacial erosion; strain analysis; deformation; structural analyses; shear zones; fabric analyses; Laurentide Ice Sheet; ice streams; ice-flow directions; Phanerozoic; Cenozoic; Quaternary |
| Program | GEM2: Geo-mapping for Energy and Minerals Mackenzie Corridor, Southern Mackenzie Surficial Mapping |
| Released | 2019 07 01 |
| Abstract | The Cameron Hills ice streams in southwestern Northwest Territories and northern Alberta are unique for the western sector of the Laurentide Ice Sheet in that unlike other ice stream corridors in the
region, they formed atop an upland instead of within topographic lowlands (e.g., Great Slave Lake and Hay River ice streams). Two distinct, cross-cutting sets of megascale glacial lineations (MSGL) occur in the Cameron Hills upland; an earlier
south-southwest flow largely preserved along the southeastern flank of the upland that was then crosscut by the southwest flow (IS #145 of Margold et al., 2015). Spectacular bedforms commence at the eastern leading edge of the Cameron Hills and many
extend >15 km in length, and have impressive length:width ratios of 75:1 or greater. There are conflicting interpretations on the nature and formation of these bedforms in terms of ice bed hardness and their erosional versus depositional nature of
the MSGL formation. Previous interpretations on the Cameron Hills MSGL were wholly derived from remote sensing data.
A field investigation was conducted in 2018 within a single elongate bedform on the Cameron Hills to determine the strain
signature and associated microstructures imparted by the palaeo-ice stream on the laterally extensive till formed at its bed. Micromorphological samples were collected to document the nature of sediment deformation, the spatial variations in the
microfabrics, and the ductile shear zones and deformation fronts within the till. Samples were also collected from the Hay River ice stream (IS#176 of Margold et al., 2015), a lowland till plain adjacent to the Cameron Hills near the
Alberta-Northwest Territories border, for micromorphological fabric comparison between the upland and lowland ice streams. A detailed micromorphological study of the till sequences beneath the Cameron Hills and Hay River ice streams is used to
unravel the complex deformation histories recorded by these glacigenic sequences, and investigate the potential factors controlling fast ice flow in these contrasting palaeo-ice stream settings.
On a macroscale, the tills formed beneath many
palaeo-ice streams are massive, lacking any visible signs of stratification and/or glacitectonic deformation structures. As a consequence, micromorphology is increasingly being used as a primary tool for the analysis of these subglacial sediments,
which provides far greater detail on their depositional and deformation histories recorded by these sediments than previously obtained from just macroscale studies. |
| Summary | (Plain Language Summary, not published)
New scientific results and interpretations from the Cameron Hills, southwest NWT, as part of the GEM-2 Southern Mackenzie Surficial Activity. This is an
international conference, to present results to scientific peers. |
| GEOSCAN ID | 313558 |
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