Lacustrine sedimentary environments in high arctic proglacial Bear Lake, Devon Island, Nunavut, Canada

被引:32
作者
Lamoureux, SF [1 ]
Gilbert, R [1 ]
Lewis, T [1 ]
机构
[1] Queens Univ, Dept Geog, Kingston, ON K7L 3N6, Canada
关键词
D O I
10.2307/1552464
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Combined catchment, subbottom acoustic, and sedimentary studies of high arctic, proglacial Bear Lake, Devon Island, were carried Out to evaluate the role lacustrine processes and Holocene catchment evolution have had oil the sedimentary record. In the proximal basin, bottom deposits up to 60 in thick are generated ill part by turbid underflows associated with peak meltwater flow from the Devon Island Ice Cap. These underflows produce rhythmically laminated Structures that are likely varves. In shallower locations. accumulation is slower and results from homopycnal distribution of fine suspended sediment throughout the proximal basin, resulting in a simple varve couplet. The distal basin is isolated from glacial meltwater by a shallow sill, although some fine-grained detrital carbonate transported by the glacial meltwater is deposited in both basins. In most locations in the distal basin Holocene sediments are less than 10 in thick. They are composed primarily of massive clay and some carbonate interrupted by irregular graded carbonate units produced by sporadic heavy summer rainfall and sediment transport from small plateau tributaries. Eolian sedimentation is also important throughout the lake, especially when high accumulations melt through the ice in the proximal basin, producing isolated grains and layers of coarse sand in the sedimentary record. Holocene ice margin changes have influenced the sedimentary record substantially, particularly during the mid-Holocene when the ice cap is inferred to have retreated from the catchment.
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页码:130 / 141
页数:12
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