Alpine Podzol Soils on the Ben Lawers Massif Perthshire

Abstract

WITH 2 PLATES SummaryCharacteristics of the soils include well-defined horizons, very low pH values and base saturation percentages, and a slight but general increase in the silt-plusclay content down the profile. X-ray diffraction shows that the soil clays are rich in mica and chlorite with subsidiary amounts of kaolinite, goethite, and lepidocrocite. The general distribution of the clay minerals in the profiles studied suggests that the weathering of chlorite leads to the formation of kaolinite in the A horizons and to the accumulation of crystalline iron-oxide minerals in the B horizons. The presence of kaolinite, taken in conjunction with recent clay mineral studies of Scandinavian and Canadian podzols, indicates that the Ben Lawers soils may pre-date the last glacial period. IntroductionEXTENSIVE blanket peat development characterizes the zone between 550 and 760 m on the mountains of West Perthshire. Within this zone, and on stable sites up to 825 m, soils of podzolized character and variable profile morpholo have developed, similar to those designated sub-

Gibbsitic soils on former nunataks: implications for ice sheet reconstruction

“…Geikie, 1894;Sissons, 1967). A number of authors contested this opinion, basing their arguments on the survival of tors on high ground (Linton, 1949(Linton, , 1955, the thickness of mountain-top detritus (Ragg and Bibby, 1966), the presence of halloysite and kaolinite in mountain soils (Stevens and Wilson, 1970) and the distribution of blockfields (Godard, 1965), but these arguments are now acknowledged to be equivocal (e.g. Sugden, 1968;Sissons, 1976;Ballantyne et a/., 1987;Hall and Mellor, 1988;Ballantyne and Harris, 1994).…”

The Weathering of Chloritic Minerals in Some Scottish Soils

“…Mitchell (1955), on the basis of decrease in amount of chlorite with depth and an even distribution throughout the particle-size range of the clay fraction, has considered chlorite to be highly stable in many Scottish soils, and Ball (1966) could find no clear pedogenic trend and no indication of new mineral phases being formed from chlorite in highly chloritic brown earths and rankers of Snowdonia. On the other hand, Perrin (1971) reported that chlorite derived from Lower Palaeozoic shales is destroyed fairly rapidly in the soil, and others have reported that the mineral readily weathers to oxides of iron and aluminium (MacEwan, 1948), saponite or vermicu lite (Smith, 1962), kaolinite (Stevens and Wilson, 1970) and vermiculite or amorphous silica (Adams et al ,197 1 ).…”

Textural properties of regoliths on vegetated steep slopes in upland regions, Scotland

“…Given time and stability, it is likely that they would develop into alpine podzols (Romans et al 1966;Stevens & Wilson 1970), podzols or brown soils (Ellis 1980a), depending on the lithology and climatic conditions. As such, they can be classed as inceptisols (Ragg 1973).…”

“…Even if clays were being formed, the coarse texture and free-draining nature of the regoliths mean that they would be rapidly removed by leaching (Reid et al 1981;Smith et al 1983). Throughflow is known to be) important in arctic-alpine regoliths (Stevens & Wilson 1970;Ragg 1973;Harris & Ellis 1980;Lewis & Grant 1980), and could result in the removal of any clay-sized material. This removal of fines by throughflow is a well-known phenomenon, and has been termed 'impoverishment' by Duchafour (1982).…”