Pedogenesis in the Alnö carbonatite complex, Sweden

Soil and rock material was sampled from three soil profiles developed on the host rocks of Alnö Island, the migmatitic gneisses (profiles G2, G4 and G5) and three profiles with alkaline or carbonatitic parent material (A1, A3 and A6) to examine the differences in pedogenesis of soils on the two very different parent materials and the influence of parent material on pedogenetical processes. All soil profiles could be classified as Cambisols with partially extremely high rock contents up to 69% gravel in profile A3. Two soils on gneissic parent material (profiles G4 and G5) already show signs of podzolization processes, which seem to have been, slowed down’ by the influence of the alkaline rocks. Furthermore, the different parent material affects the vegetation considerably. The nutrients derived from alkaline/carbonatitic rocks are favourable for the growth of the vegetation in an otherwise rather acidic environment of the gneisses.