Preliminary stratigraphic and geotechnical investigations of the glaciolacustrine and loess deposits around the city of Whitehorse (NTS 105D/11), Yukon.

This paper presents the preliminary results of a study investigating the stratigraphy and basic geotechnical properties of the surficial geology deposits observed in the bluffs around the city of Whitehorse. A total of eleven sections were examined on both the east and west banks of the Yukon River. Representative stratigraphic units were analysed for grain size distribution; deposits ranged in size from silt and clay to coarse gravel. Most of the observed sediments represent the glaciolacustrine depositional environment of Glacial Lake Laberge with the exception of a loess unit exposed near the top of the sections. Consistency indices of seven silt and clay-rich samples collected in the bluffs surrounding Whitehorse indicate a low plasticity comparable with other Canadian loess units and the glaciolacustrine bluffs around Kamloops and in the Elk Valley of British Columbia. The soil unconfined compressive strength was estimated using a pocket penetrometer and the dry silt and clay-rich units were found to have strength estimates up to two orders of magnitude greater than the sand-rich units.