CGRG Bibliography of Canadian Geomorphology
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Author : Ennis, M.J.; Brock, B.E.; and Wolfe, B.B.
Date : 2008.
Title : A multi-centennial record of environmental change from an evaporation- dominated lake, Slave River Delta, NWT.
Publication : 2008 Annual Meetings of the Canadian Association of Geographers, Ontario Division and the American Association of Geographers, East Lakes Division. October 17-19, 2008. Brock University. St. Catharines, Ontario.
Issue :
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Abstract
The Slave River Delta (SRD), NWT, is a productive northern wetland ecosystem. Located at the terminus of the Peace-Athabasca-Slave River watershed, this ecosystem is a sensitive indicator of environmental change caused by factors ranging from climate variability to alterations in river discharge. This study aims to reconstruct past hydrological conditions for a small evaporation-dominated lake (SD 34) in the relict Slave River Delta close to the present day shoreline of Great Slave Lake. Evidence of a possible Great Slave Lake high stand is apparent in the landscape to the south of the SRD. Paleolimnological methods were used to determine if this apparent expansion inundated the study lake and if so, the timing of the high stand. This study focuses on results from chronological and geochemical analyses on both 38-cm gravity and overlapping 71-cm Russian cores collected from SD 34. A record of sediment deposition ranging from ~1717 to 1975 AD was developed using 210Pb analyses. Six stratigraphic zones were identified from loss-on-ignition and carbon and nitrogen elemental and stable isotope analysis. A contact at 78cm core depth was seen in the geochemical data at the convergence of Zone 2 and 3 (~1760 AD). This contact represented a shift toward increased production. The shift was identified as the transition of SD34 from an embayment of Great Slave Lake to the present-day shallow lacustrine depositional environment. This study acts as a starting point for continued investigation of a Great Slave Lake high stand during the Little Ice Age.
Bibliography of Canadian Geomorphology