Paleohydrology and paleoclimate records in a saline prairie lake core: mineral,isotope and organic indicators |
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| Authors: | D R Van Stempvoort T W D Edwards M S Evans W M Last |
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| Institution: | (1) Environmental Sciences Division, National Hydrology Research Institute, 11 Innovation Blvd., S7N 3H5 Saskatoon, Saskatchewan, Canada;(2) Department of Earth Sciences, University of Waterloo, N2L 3G1 Waterloo, Ontario, Canada;(3) Department of Geological Sciences, University of Manitoba, R3T 2N2 Winnipeg, Manitoba, Canada;(4) Present address: Saskatchewan Research Council, 15 Innovation Blvd., S7N 2X8 Saskatoon, Saskatchewan, Canada |
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| Abstract: | This pilot study examines the potential of obtaining a sedimentary record of paleoenvironmental/climatic/hydrologic conditions for saline Redberry Lake in southern Saskatchewan, Canada. The tools are mineralogy, stable isotopes and pigments. The upper meter of an offshore sediment core contains 10 to 20% by weight aragonite (CaCO3), which apparently precipitated in the water column. The  18O and 13C of the bulk aragonite (corrected for content of detrital calcite) vary by 4 to 5 . Enrichment in 18O in aragonite is significantly correlated with pigment concentrations (chlorophyll a, phaeophytin). The 18O and pigment data provide evidence for relatively dry and/or warm conditions and high limnetic productivity for the period 2500 to 1500 yrs B.P. After 1500 B.P., the climate was apparently similar to the present, with two episodes of relatively enhanced productivity, dryness and/or warmth, at around 1000 to 900 and 500 to 200 B.P. During the past century, Redberry Lake has decreased approximately 8 m in depth and its salinity has doubled. No clear sedimentary signal was observed in response to these recent hydrologic trends. These changes have not been associated with a significant climate trend in the region, but may have been induced by land use changes in the catchment.This publication is the third of a series of papers presented at the Conference on Sedimentary and Paleolimnological Records of Saline Lakes. This Conference was held August 13–16, 1991 at the University of Saskatchewan, Saskatoon, Canada. Dr. Evans is serving as Guest Editor for this series. |
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| Keywords: | sediments paleohumidity paleosalinity aragonite lake level pigments |
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