Paleolimnologic Evidence of High Arctic Late Quaternary Paleoenvironmental Change: Truelove Lowland, Devon Island, N.W.T., Canada,
UNIVERSITY OF WESTERN ONTARIO LONDON
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Truelove Lowland 75033N, 84 40W is a small area 43 km2 of relatively high biological diversity in the midst of the more typical Polar Desert of the Canadian High Arctic. Much of the Lowland is presently covered by freshwater lakes some of which are sufficiently deep 7-8.5 m to contain stratified lake sediments. Sediment cores 2 m long from the larger lakes have been analyzed for diatoms and chemical composition and reveal a stratigraphic record that spans the last 10,600 years. This record indicates that lake development in the Lowland began as a series of shallow marine lagoons isolated from the sea as a result of glacio-isostatic rebound and the progressive emergence of the Lowland from the sea. Following isolation, the timing of which was strongly controlled by elevation and the relative rate of isostatic uplift, the lakes have been flushed with freshwater. Since that time the lakes have remained oligotrophic and lake sedimentation has been dominated by variations in non-biogenic factors and particularly by variations in the influx of allochthonous materials from within the lake catchments. Over time, the progressive stabilization of surface materials and pedogenesis within the lake catchments has been marked by decreasing amounts of Cr, As and Na in the sediments and an increase in allochthonous Fe and Mn.
- Physical and Dynamic Oceanography
- Hydrology, Limnology and Potamology