Contemporary and post-glacial rates of aeolian deposition in the Coast Mountains of British Columbia, Canada

Contemporary and post-glacial rates of aeolian deposition are determined for three small catchments that straddle the alpine-subalpine ecotone in the Pacific Ranges of the Coast Mountains of British Columbia. From process measurement over a single year, the mean annual regional (allochthonous) rate of aeolian deposition for the catchments is estimated to be approximately 11 g m(-2). The average rate of annual deposition over the post-glacial period is calculated from the soil profiles to be c. 6 g m(-2), although fallout rates are likely to have varied significantly over the Holocene epoch due to changes in climate and catchment conditions. It would appear that the vegetated ground strata in these catchments are net receivers of aeolian dust fallout. Consequently, many of the soils are cumulic in nature and protect the bedrock in these catchments from subaerial weathering. These results have implications for sediment transfers in alpine and subalpine environments in southwestern British Columbia.