| Title | Microsedimentological evidence of vertical fluctuations in subglacial stress from the northwest sector of the Laurentide Ice Sheet, Northwest Territories, Canada |
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| Author | Rice, J M ;
Menzies, J; Paulen, R C; McClenaghan, M B |
| Source | Canadian Journal of Earth Sciences vol. 56, no. 4, 2018 p. 363-379, https://doi.org/10.1139/cjes-2018-0201 |
| Image |  |
| Year | 2018 |
| Alt Series | Earth Sciences Sector, Contribution Series 20160177 |
| Publisher | Canadian Science Publishing |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf (Adobe® Reader®); html |
| Province | Northwest Territories; Alberta; British Columbia |
| NTS | 75D; 75E; 75L; 84M; 84N; 84O; 84P; 85A; 85B; 85C; 85D; 85E; 85F; 85G; 85H; 85I; 85J |
| Area | Great Slave Lake; Pine Point; Hay River; Yellowknife |
| Lat/Long WENS | -119.0000 -110.0000 63.0000 59.0000 |
| Subjects | surficial geology/geomorphology; sedimentology; stratigraphy; geophysics; glacial history; glaciation; ice flow; depositional history; depositional environment; sediment dispersal; depositional models;
deformation; glacial deposits; tills; stress analyses; shear stress; lineations; thin section microscopy; pebble lithology; fabric analyses; lithostratigraphy; sedimentary structures; rheology; remote sensing; satellite imagery; Pine Point Mining
District; Western Canada Sedimentary Basin; Canadian Shield; Laurentide Ice Sheet; ice-flow directions; Phanerozoic; Cenozoic; Quaternary |
| Illustrations | location maps; geoscientific sketch maps; satellite images; photographs; photomicrographs; tables; schematic representations; ternary diagrams; equal-area stereonet projections; charts;
stratigraphic sections; rose diagrams; profiles |
| Program | GEM2: Geo-mapping for Energy and Minerals Mackenzie Corridor, Southern Mackenzie Surficial Mapping |
| Released | 2018 11 14 |
| Abstract | The past-producing Pine Point lead-zinc mining district, Northwest Territories, Canada, provides a unique opportunity to study the role of glacial dynamics in a thick, continuous till succession that
has not been influenced by the underlying bedrock topography. Parts of the Pine Point mining district are covered by >20 m of subglacial Quaternary sediments (till) associated with the former Laurentide Ice Sheet. Till facies exposed in unreclaimed
open-pit K-62 have been classified into four separate units. Micro- and macrosedimentological analyses were undertaken to identify the change in subglacial stress during sediment deposition and across till unit boundaries. An analysis of high- and
low-angle microshears (lineations) in thin sections produced from these till units indicate that there is a noticeable decrease in the abundance of low-angle shear features immediately below till unit boundaries. The deformation of low-angle shears
in the underlying tills was likely caused by remobilization of the overlying till unit. This remobilization is consistent with aggradation-constant entrainment decay mechanisms for subglacial till emplacement and accretion and subglacial dispersion
models. |
| Summary | (Plain Language Summary, not published)
This paper is the product of the GSC's GEM1 RAP Bursary funded MSc thesis by Jessey Rice. It is a summary of the detailed sedimentological work that was
undertaken with the regional stratigraphy of the western sector of the Laurentide Ice Sheet. Examination of a till sequence, by thin section micromorphology, will provide a better understanding of depositional mechanics under a temperate ice sheet.
This paper will benefit academia in a better understanding of the subglacial processes that impacted western and northern Canada. |
| GEOSCAN ID | 299245 |
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