CGRG Bibliography of Canadian Geomorphology
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Author : Harris, S.A.; and McDermid, G.
Date : 1998
Title : Frequency of debris flows on the Sheep Mountain fan, Kluane Lake, Yukon Territory.
Publication : Zeitschrift fur Geomorphologie
Issue : 42(2):
Page(s) : 159-175.
Abstract
The debris flow track on the east side of Sheep Mountain, Yukon Territory, consists of an upper accumulation area (1350-1900 m elevation), a constriction caused by a hard band of rock which acts as a dam (1350-1150 m), a box canyon with talus along its sides (880-1150 m), and the debris flow fan below 880 m. Tree ring counts indicate that there have been no major flows through the box canyon during the last centruy. However, the presence of White River ash (1220 BP) below eight debris flow deposits in a section in the fan suggests an average frequency of one flow every 150 years. Up to 5 m of diamicton was deposited during each event. Weak paleosols or stone lines separate the diamictons, the paleosols indicating an appreciable break in time between each event. The present surface soil on the fan is less well developed than these paleosols. Thus this fan represents the higher volume, lower frequency debris member of a spectrum of active debris flows over icy permafrost, and as such, completes the range of variation of these active systems (see table 5). It differs from the fossil debris flow fans in that it lacks the deep red Altithermal soil.
Bibliography of Canadian Geomorphology