ABSTRACT: Multiple glaciations in the Foothills, Rocky Mountain House area, Alberta

CGRG Bibliography of Canadian Geomorphology
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Abstract

The results of this study of the surficial deposits in the Rocky Mountain House area (Rocky Mountain Foothills region) indicate that in Wisconsin times the study area experienced multiple glaciations. Only one Laurentide advance (Athabasca-Sylvan Lake) was documented, but this ice probably remained in the area for the whole of the Late Wisconsin. One Early Wisconsin (Hummingbird-Baseline) and two Late Winsconsin (Lamoral and Jackfish Creek) Rocky Mountain advances were also documented. One "old glacial" area (Brazeau and Ram Ranges) situated above 5500 ft (1660 m) was glaciated during the Early Wisconsin but remained ice free in Late Wisconsin times. A number of proglacial lakes, impounded by Late Wisconsin ice masses, formed in the river valleys. A major lake (glacial Lake Caroline) occupied a substantial portion of the area during deglaciation. Rocky Mountain meltwaters were impounded by the Laurentide ice mass and cut successively lower spillways in the east and southeast. The entire study area was probably ice free soon after 9600 BP. During the course of this study, the surficial deposits were mapped, and samples were taken from exposures and from material collected by dry auger drilling. Supplementary laboratory tests included till fabric analysis, and lithological, heavy mineral, and carbonate analyses. Only heavy mineral analysis and pebble counts were found to be useful for differentiating among the tills The relative ages of the three Rocky Mountain advances were established from stratigraphic and morphological evidence, because of a lack of suitable radiometry data.

Bibliography of Canadian Geomorphology