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Topography of drained thermokarst lake basins in Old Crow Flats, northern Yukon (working paper)

  • June 2015
Authors:
Pascale Roy-Léveillée at Laurentian University
Pascale Roy-Léveillée
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Thermokarst sediments and sedimentary structures, Tuktoyaktuk Coastlands, western Arctic Canada
Article
Abrupt climate warming during glacial–interglacial transitions promotes regional thermokarst activity in areas of ice-rich permafrost. The ensuing thaw-related processes of melt-out, soft-sediment deformation and resedimentation may produce widespread thermokarst sediments and sedimentary structures. Examples of the most distinctive thermokarst sediments and sedimentary structures from the Tuktoyaktuk Coastlands, western Arctic Canada, comprise: (1) soft-sediment deformation structures (thermokarst involutions) in a palaeoactive layer; (2) ice-wedge casts and composite-wedge casts; (3) peaty to sandy diamicton deposited mainly by debris flows in retrogressive thaw slumps; and (4) a basal unit of diamicton and/or impure sand in some thermokarst-basin sequences, deposited by progradation of resedimented materials in thermokarst lakes. Many of the thermokarst sediments and sedimentary structures in the Tuktoyaktuk Coastlands formed as a result of rapid climate warming during the last glacial–interglacial transition, although some continue to form at present due to local (non-climatic) factors.Identification of thermokarst sediments and sedimentary structures in the geological record requires evidence for the thaw of excess ice. Direct evidence for the former occurrence of excess ice includes: (1) ice-wedge casts; (2) composite-wedge casts; (3) lenticular platy microstructures in frost-susceptible sediment; (4) certain near-surface brecciation of frost-susceptible bedrock; and (5) ramparted depressions attributed to the decay of frost mounds. Indirect evidence for former excess ice results where thaw consolidation initiates soft-sediment deformation or gelifluction.
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Vegetation history of a polygonal peatland, northern, Yukon
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Pollen, macrofossils and matrix composition are described for a 221 cm core from a polygonal peatland overlying a late-Wisconsin lakebed. A hydroseral succession of wetland communities occurred at the site, and included a submerged assemblage with Chara, a Carex aquatilis - Eleocharis marsh, a fen, and finally a Sphagnum - Ledum bog. A transition about 9,600 B.P. to a wetter S. balticum - Andromeda carpet is attributed to formation of permaforst and polygonal ice wedges. This community, sometimes with S. compactum and Chamaedaphne, prevailed until about 3,000 B.P. when the polygon became high centered, and peat growth declined. Peat growth rate is determined from 11 14C dates, and is used to calculate pollen influx. Apparent periodic oscillations every 2,000 years, in total influx, are not accepted as sufficient evidence of treeline fluctuations.
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Remote sensing, numerical modeling, and stable isotope
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Yukon, Canada: Remote sensing, numerical modeling, and stable isotope
Physical and temporal factors controlling 905 the development of near-surface ground ice at Illisarvik, western Arctic 906 coast
  • Jan 2012
  • 1096-1110
  • H B O'neill
  • C R Burn
O'Neill HB, Burn CR. 2012. Physical and temporal factors controlling 905 the development of near-surface ground ice at Illisarvik, western Arctic 906 coast, Canada. Canadian Journal of Earth Sciences 49: 1096-1110. doi: 907 10.1139/e2012-043.
Hydroseral Histories of the Old Crow Peatlands
  • Jan 1985
  • L Ovenden
Ovenden L. 1985. Hydroseral Histories of the Old Crow Peatlands, Northern
Character-915 izing post-drainage succession
  • Jan 2012
  • P Regmi
  • G Grosse
  • M C Jones
  • B M Jones
  • K W Anthony
Regmi P, Grosse G, Jones MC, Jones BM, Anthony KW. 2012. Character-915 izing post-drainage succession in thermokarst lake basins on the Seward 916
Alaska with TerraSAR-X backscatter and Landsat-based NDVI 917 data
  • 3741-3765
  • Peninsula
Peninsula, Alaska with TerraSAR-X backscatter and Landsat-based NDVI 917 data. Remote Sensing 4: 3741-3765. doi:10.3390/rs4123741.
Meteorology and wave climate
  • Jan 2002
  • D Resio
  • S Bratos
  • E Thompson
Resio D, Bratos S, Thompson E. 2002. Meteorology and wave climate. In
The paleoshoreline of basin 2 is traced with a dashed line where the drainage outlet of basin 2 connects basins 2 and 3 (see Fig. 2). The location of surveyed transects (black lines), temperature sensors (
  • Jan 1976
  • P Roy-Leveillee
  • C R Burn
Roy-Leveillee P, Burn CR. 2010. Permafrost conditions near shorelines of 923 oriented lakes in Old Crow Flats, Yukon Territory. In Proceedings of the Figure 4: Aerial photographs of (a) basin 1 taken on June 15 th , 1996 and (b) basins 2 and 3 taken on July 13 th , 1976. The paleoshoreline of basin 2 is traced with a dashed line where the drainage outlet of basin 2 connects basins 2 and 3 (see Fig. 2). The location of surveyed transects (black lines), temperature sensors ( ), weather station ( ), peat bottom samples ( * ) and tree cores ( †) are indicated in each basin.