Fjölrit RALA - 15.06.2004, Síða 96

can be defined as a function of weathering kinetics, the existence of adequate conditions for
the stabilisation of intermediate, metaestable, products, and absence of vertical redistribution.
Therefore, the allocation of the soils formed by this process as Andosols (or Andisols) is not
only a consequence of fulfilling the conditions required by the classification systems but also
because many of their properties are close to those of typical Andosols, particularly to ‘non-
allophanic’ or ‘aluandic’ Andosols, dominated by Al(Fe)-humus complexes.
Summary of the chemical and mineralogical characteristics of the main weathering and soil forming processes
that lead to the formation of non-volcanic Andosols (adapted from García-Rodeja & Macías, 1984 and Calvo &
Macías, 1992)_________________________________________________________________________________
Aluminosiallitization Andosolization Monosiallitization (incipient) Monosiallitization
Biogeochemical processes Geochemical processes
Horizons A A, AB Bw,C B, C
Parent materials Granites Schists Slates, Shales Intermediate & basic rocks Granites, Schists Shales, Slates Basic rocks Basic rocks Biotite-rich schists
Mobility Si > Al, Fe Si > Al, Fe Si > Al, Fe Si >A1, Fe
Weathering mechanism Acid complexolisis (moderate) Acid hydrolisis Acid hydrolisis Hydrolisis Acid hydrolisis Hydrolisis
Weathering of primary minerals Moderate Incipient Moderate Total
Evolution of2:l minerals Degradation, aluminization Degradation Degradation Destruction
Colloidal components Al-humus, Allophane Halloysite A1 interlay. 2:1 phyll. Al(Fe)-humus Allophane, A1 gels, Halloysite Gibbsite Allophane, A1 gels Kaolinite Goethite
Soil properties pH pH NaF %C %Alo AIrci (cmolc/kg) P ret. (mg/kg) 4.8 (4.0-5.5) 11.0 (8.9-11.6) 6 (3-16) 0.7 (0.3-2,2) 3.5 (1.4-6.6) 1100 (400-1900) 4.9 (4.5-5.8) 11.0(10.2-11.7) 9 (5-14) 2.6 (1.6-4.1) 2.1 (0.6-3.0) 2000 (1300-2800) 5.0 (4.4-5.9) 10.7 (8.0-11.5) 1 (0.1-2) 0.6 (0.2-1.6) 2.0 (0.7-3.2) 850 (200-1400) 5.2 (4.5-5.9) 9(8.0-10.1) 0.8 (0.3-1.3) 1.2 (0.3-2.5) 400 (200-600)
References
Baumler, R., and Zech, W. 1994. Characterization of Andisols developed from non volcanic material in eastem
Nepal. Soil Science, 158:211-217.
Caner, L., Bourgeon, G., Toutain, F., and Herbillon, A.J. 2000. Characteristics of non-allophanic Andisol
derived from low activity regoliths in Nilgiri Hills (Southem India). European Joumal of Soil Science, 51:554-
563.
Delvaux, B., Strebl, F., Maes, E., Herbillon, A.J., Brahy, V., and Gerzabek, M. 2004. An Andosol-Cambisol
toposequence in the Austrian Bohemian Massif. Catena, 56:31-43.
García-Rodeja, E. 1985. Sobre la clasificación de Andosoles y su existencia en materiales no volcánicos de
Galicia (NO de Espaiia). An. Edaf. Agrob., 44: 1651-1661.
García-Rodeja, E., and Macías, F. 1984. Caracterización de suelos ácidos (Podsoles-Andosoles-Suelos
Alumínicos) de Galicia. Relación con los procesos edafo-geoquímicos. I Congreso Nacional de la Ciencia del
Suelo, 589-602.
García-Rodeja, E.; Silva, B., and Macías, F. 1987. Andosols developed ffom non-volcanic materials in Galicia,
NW Spain. Joumal of Soil Science, 38: 573-591.
Macías, F., and Calvo, R. 1992. Caractérisation pédogéochimique des sols de la Galice (NW Espagne) en
relation avec la diversification lithologique. Mise en évidence d'un milieu de transition entre les domaines
tempérés et subtropicaux humides. C.R.Acad.Sci.Paris, t.315, Série II, p.1803-1810.
Macías, F., Puga, M., and Guitián, F. 1978. Caracteres ándicos en suelos sobre gabros de Galicia. An. Edaf.
Agrob., 37: 187-203.
75