A quantitative soil-stratigraphic approach to the correlation and dating of post-glacial river terraces in Glen Feshie,western Cairngorms

Little is known about Holocene river terrace development in upland Scottish valleys. Interpretation of many of the terrace sequences, previously suggested to have been formed by meltwaters either from the last Scottish ice sheet or the Loch Lomond Advance, has generally been based on morphological data. In this paper an alternative approach to the traditional height-based method of terrace correlation and dating is presented using data from Glen Feshie, western Cairngorms. Terrace fragments are numerically classified and objectively grouped using quantitative soil-stratigraphic data. Principal Components Analysis is used to both quantify pedological data and separate temporal trends in the data from variance due to local site factors. The scores on the temporal component are used to derive soil-stratigraphic units developed on the surficial sediments of the Glen Feshie terraces by grouping soil sites using a hierarchical clustering technique. This provides evidence for at least five soil-stratigraphic units developed on the fluvial surfaces. Various methods of absolute dating control permits association of these surfaces with five phases of terrace development. These are placed tentatively at 13 000, 10 000, 3600, 1000, and 80 radiocarbon years B.P., suggesting at least three phases of valley floor incision in Glen Feshie during the late Holocene.