Palaeohydrology of the southwest Yukon territory, Canada, based on multiproxy analyses of lake sediment cores from a depth transect


Anderson, Lesleigh, Abbott, Mark B., Finney, Bruce P. and Edwards, Mary E. (2005) Palaeohydrology of the southwest Yukon territory, Canada, based on multiproxy analyses of lake sediment cores from a depth transect The Holocene, 15, (8), pp. 1172-1183. (doi:10.1191/0959683605hl889rp).

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Description/Abstract

Lake-level variations at Marcella Lake, a small, hydrologically closed lake in the southwestern Yukon Territory, document changes in effective moisture since the early Holocene. Former water levels, driven by regional palaeohydrology, were reconstructed by multiproxy analyses of sediment cores from four sites spanning shallow to deep water.Marcella Lake today is thermally stratified, being protected from wind by its position in a depression. It is alkaline and undergoes bio-induced calcification. Relative accumulations of calcium carbonate and organic matter at the sediment/water interface depend on the location of the depositional site relative to the thermocline. We relate lake-level fluctuations to down-core stratigraphic variations in composition, geochemistry, sedimentary structures and to the occurrence of unconformities in four cores based on observations of modern limnology and sedimentation processes. Twenty-four AMS radiocarbon dates on macrofossils and pollen provide the lake-level chronology. Prior to 10 000 cal. BP water levels were low, but then they rose to 3 to 4 m below modern levels. Between 7500 and 5000 cal. BP water levels were 5 to 6 m below modern but rose by 4000 cal. BP. Between 4000 and 2000 cal. BP they were higher than modern. During the last 2000 years, water levels were either near or 1 to 2 m below modern levels. Marcella Lake water-level fluctuations correspond with previously documented palaeoenvironmental and palaeoclimatic changes and provide new, independent effective moisture information. The improved geochronology and quantitative water-level estimates are a framework for more detailed studies in the southwest Yukon.

Item Type: Article
Digital Object Identifier (DOI): doi:10.1191/0959683605hl889rp
ISSNs: 0959-6836 (print)
Related URLs:
Keywords: Lake-level, effective moisture, palaeoclimate, palaeolimnology, carbon isotopes, nitrogen isotopes, Yukon Territory, Canada, Holocene
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ePrint ID: 55291
Date :
Date Event
2005Published
Date Deposited: 01 Aug 2008
Last Modified: 16 Apr 2017 17:44
Further Information:Google Scholar
URI: http://eprints.soton.ac.uk/id/eprint/55291

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