Original paper

Impact of sedimentary processes and paleopedogenesis on Holocene Luvisol formation

Müller, Susann; Thiemeyer, Heinrich


Luvisols were studied in the Spessart Mountains in central Germany. In this low mountain range the bedrock is covered by Pleistocene periglacial slope deposits that constitute the parent material for soil formation. In general, the genesis of Luvisols in the study area is bound to the occurrence of a tripartite stacking of periglacial layers: A differentiation of eluvial (E-) and illuvial (Bt-) horizon is already developed within the upper layer. The intermediate layer carries the main argillic horizon of those profiles whereas the basal layer is only marginally affected by soil formation. By the help of soil micromorphology it was possible to identify numerous fragments of paleosol material within the intermediate layer (2Bt-horizon) accounting for large proportions of the total clay content of this horizon. While the formation of the upper layer, parts of the intermediate layer were reworked and incorporated into the newly formed slope deposit. As a result, the lower part of the upper and the whole intermediate layer contained large amounts of clay before the onset of Holocene pedogenesis. Recent lessivation, evidenced by undisturbed clay illuviations, affected the profile. Consequently this soil formation masks prior differences in clay content due to included paleosol material. Soil formation is dominated by the paleosol remnants and therefore elucidates the impact of late glacial conditions on Holocene soils. Besides, a Luvisol was identified which was not formed in periglacial slope deposits but in Holocene colluvium. In this case paleosol remnants were totally absent. Hence, a precise reconstruction of Luvisol-genesis is enormously improved by micromorphological analyses.


pleistocene periglacial slope depositsluvisolpaleosolmicromorphology