The Glacial geomorphology of the Kananaskis Valley, Rocky Mountain Front Range, southern Alberta
The Kananaskis Valley is a tributary valley to the south of the arterial Bow Valley at the eastern limit of the Front Ranges of the Rocky Mountains, some 80 km west of Calgary. Present-day glaciers within the study area flow both into the Kananaskis Valley and also across the Continental Divide into the Elk Valley. Surficial deposits and erosional landforms within a 2000 square kilometer area north and east of the Continental Divide indicate that there were at least eight glacial episodes ) each smaller than the previous one, within the valley, and also at least three minor Holocene glacial events. In addition to aerial photograph interpretation and mapping, identification of the glacial episodes is aided by till fabric analyses and laboratory analysis, comprising lithological, grain-size and carbonate analysis. The glacial episodes are correlated with those described by Stalker (1973) in the northern part of the study area, by Rutter (1972) in the Bow Valley, and by Tharin (1960) in the Calgary area. The oldest "highest glaciation" is identified only by scattered erosional landforrrs, and the origin of the glacier occupying the Kananaskis Valley at this time is unknown. It is correlated with Glacier I of Stalker. During the "Rocky Creek Advance", the northward exit of the Kananaskis glacier from this valley was blocked by Bow Valley ice occupying Marmot and Pigeon Mountain glacial diffluence cols (Walker, 1971); Bow Valley ice filled the Lower Kananaskis Valley. Till veneers containing Gog Group erratics from the Mount Eisenhower area of the Bow Valley and trimlines at high elevations are the main evidence for this glaciation. It is correlated with Glacier II of Stalker, the Bow Valley Advance of Rutter, and the Spy Hill Advance of Tharin. This is the last occasion when Kananaskis ice could have moved south over Elk Pass across the Continental Divide. Similar but more widespread evidence is used to delimit the third "Mount Wintour Episode". At this time the Kananaskis glacier was able to advance at least to the Barrier Lake area; the Pigeon Mountain Col was still occupied by Bow Valley ice. This advance is correlated with Glacier III of Stalker and the Morley Advance of Tharin; no corresponding advance was recognized by Rutter in the Bow Valley. The terminus of the Kananaskis glacier during the following "Limestone Mountain Episode" lay beyond the limit of the study area at Barrier Lake. This event is recorded by well-marked lateral moraines and ice contact glaciofluvial deposits. Standstill positions during the retreat of this glacier at Marmot and Galatea Creeks have been identifed from meltwater channels and associated glaciofluvial deposits. This is correlated with Glacier IV of Stalker, and the Canmore Advance of RutteL The two youngest advances of Kananaskis glaciers, the "Power Plant Episode" and the "Boulton Creek Episode", advanced no further than the north and south ends of Lower Kananaskis Lakes respectively. Evidence includes a terminal moraine for the older, and a large glaciofluvial complex for the younger. No new radiometric data is introduced, but archaeological evidence (Aresco Ltd., 1977) from the Boulton Creek area of Lower Kananaskis Lake shows the area to have been unglaciated by 8000 years BP.
Bibliography: p. 179-189.
Hawes, R. J. (1977). The Glacial geomorphology of the Kananaskis Valley, Rocky Mountain Front Range, southern Alberta (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/18930