| Title | Timing, rates and geomorphic controls on Holocene loess and aeolian sand deposition using multiple chronometric methods, southeastern Cordillera, Alberta, Canada |
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| Author | Wolfe, S A ; Lian,
O B |
| Source | Aeolian Research vol. 50, 100687, 2021 p. 1-16, https://doi.org/10.1016/j.aeolia.2021.100687 |
| Image |  |
| Year | 2021 |
| Alt Series | Natural Resources Canada, Contribution Series 20200054 |
| Publisher | Elsevier |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf; html |
| Province | Alberta |
| NTS | 82O; 82N/09; 82N/15; 82N/16; 83B/03; 83B/04; 83B/05; 83B/06; 83B/11; 83B/12; 83B/13; 83B/14; 83C; 83D; 83E; 83F; 83G/04; 83G/05 |
| Lat/Long WENS | -120.0000 -114.0000 54.0000 51.0000 |
| Subjects | surficial geology/geomorphology; geochronology; Science and Technology; Nature and Environment; Holocene; loess; eolian deposits; tephrochronology; radiocarbon dating; Canadian Cordillera; Climate
change; Phanerozoic; Cenozoic; Quaternary |
| Illustrations | location maps; tables; ternary diagrams; plots; photographs; stratigraphic columns; schematic sections |
| Program | Climate Change
Geoscience Permafrost |
| Released | 2021 03 06 |
| Abstract | Glacier-fed river systems represent potentially significant sediment sources for aeolian processes owing to sediment production, flow seasonality, and winds within mountain settings. We investigate the
timing and rates of Holocene loess and aeolian sand deposition in three major river valleys (Bow, North Saskatchewan and Athabasca) of the southeastern Canadian Cordillera through aeolian stratigraphy and dating of sedimentary materials. Source
sediments are glacially-derived, seasonally-exposed alluvial deposits. Variation in river morphology promotes source-sediment deposition influenced by bedrock configuration, tributary stream deposition and alluvial fans. Two main settings for aeolian
deposition are source-proximal valley-bottom sites and more distal lower-valley sites in sub-alpine and montane forest ecozones. Dating is well-constrained by radiocarbon ages and tephrochronology. Quartz optical dating is complicated, likely owing
to minimal recycling of grains and quartz provenance. Mass accumulation rates (MARs) indicate that aeolian deposition was initiated soon after deglaciation and has occurred nearly continuously for at least 10000 years. Loess MARs ranged between 100
and 2500 g?m?? 2?a?? 1 during the Holocene. Rates in the last 3000 years are generally two to three times higher than those observed for earlier periods, and are highest in most recent times. We attribute Holocene accumulation at these sites in
general to fluvial source sediment availability and the efficacy of forested valleys as sediment traps. The late Holocene increase in MARs is primarily attributed to increased glacial silt and alluvial sediment supply during neoglacial fluctuations
including the Little Ice Age. |
| Summary | (Plain Language Summary, not published)
This study documents eolian deposition along rivers of the southern Canadian Cordillera. Rates of deposition are generally higher than previously
considered. River systems with shallow depositional basins are sediment sources. Eolian deposition has occurred due to consistent localized sediment sources. Recent increased rates of deposition may be attributed to increased silt from
glaciers. |
| GEOSCAN ID | 328172 |
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