Characteristics and Genesis of Some Subalpine Podzols (Spodosols), Banff National Park, Alberta

Two well-drained pedons within the subalpine ecotone at Bow Pass, Banff National Park, have been markedly influenced in their development by the chemical and physical composition of the parent materials. Of particular importance has been the presence of a surficial aeolian deposit containing significant amounts of volcanic ash of unknown origin. The pedogenic degradation of the ash component under strongly acidic conditions results in the formation of Ae horizons with a characteristic clay mineral suite dominated by montmorillonite, and podzolic B horizons containing high concentrations of amorphous iron and aluminum oxides. Some of the extractable Fe and A1 oxides present in the podzolic B horizons have been produced as a result of intensive weathering in situ rather than as a result of podzolization sensu stricto. An underlying calcareous till tends to restrict soil profile development such that the sola of the Podzols are shallow and largely confined to the surficial aeolian deposit.