CGRG Bibliography of Canadian Geomorphology
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Author : Gudjonsson, K.
Date : 1992
Title : Hummocks of the Fosheim Peninsula, Ellesmere Island, Northwest Territories
Publication : Unpublished M.Sc. thesis. University of Toronto, Toronto
Issue :
Page(s) :
Abstract
Slope hummocks differ from earth hummocks in their size, distribution, internal morphology and granulometry. At sites on the Fosheim Peninsula they are usually about 25 cm high, 65 cm long and are composed of silty sand (average grain size 3.5 phi, 90% of the grains 2-5 phi, typical silt/sand ratio 70/30 and clay portion less than 5%). They occur on moderate to steep slopes (8-27 degrees) and their distribution can be correlated with the occurrence of deep winter snow accumulation unconsolidated fine-grained surface materials and niveo-aeolian deposition. Their internal morphology exhibits a series of bands running sub-parallel to the surface and deformed in the downslope direction. The results of micromorphological studies indicate that these bands represent depositional events. These hummocks probably originate due to a combination of desiccation cracking, wash processes and niveo-aeolian deposition. Niveo-aeolian material deposited in the desiccation cracks is removed by wash processes, while that deposited in the centre of the polygon is preserved and contributes to the growth of the hummock. Vegetation plays an important role in stabilizing the forms and protecting them from erosion. The slope hummocks are moved downslope by mass movement processes (solifluction) and their internal structures are deformed in the process.
Bibliography of Canadian Geomorphology