Valley-filling basalts of the Selkirk Volcanics north and west of the Pelly River-Yukon River confluence, range in age from early Pleistocene to Holocene. Soils formed on the older surfaces have complex parent materials reflecting early Pleistocene glaciation and significant loess accumulation. A diamicton overlying the early Pleistocene basalt is covered by up to 1 m or more of calcareous loess, and shows no field evidence of weathering or soil formation. Middle Pleistocene basalt has a similar depth of loess cover and appears fresh and unweathered. Lava flows originating on the south side of the Volcano Mountain cinder cone display vegetation ranging from discontinuous lichen and moss cover to white spruce-aspen forest. Soil profile development varies correspondingly from almost nil to reddish-brown Brunisolic soils with ~30 cm of B horizon, depending on substrate age and/or the presence of lapilli deposits overlying the flows.
