Landscape history mirrored in colluvial profiles: A multi-proxy approach from a Luvisol region in Central Czechia

Abstract

Colluvisols represent an important geoarchive widely used to reconstruct of a range of processes related to the evolution of soil cover. Interpretation of Holocene landscape evolution based on the study of Colluvisols is becoming more important in areas where other proxy data, particularly archaeological and paleoenvironmental records, are lacking. The present study provides a detailed insight into the characteristics and development of two deep Colluvisols located in the Luvisols pedogeographic region in Central Czechia. Based on a multi-proxy approach combining optically stimulated luminescence dating, anthracology, soil micromorphology, clay mineralogy and geochemical analyses, it identifies the main sedimentary periods and describes both the dynamics of upbuilding of Colluvisol profiles and post-depositional pedogenesis. The position in the slope system and the provenance of the material influence the energy of deposition. The upper part of the side valley is characterised by rapid sedimentation of poorly sorted material, whereas the end part of the valley is described by calm sedimentation followed by intensive depletion. The most pronounced post-depositional features were due to bioturbation and redox processes. Although the pedological features associated with the clay illuviation are mainly preserved in the form of redeposited fragments, the in-situ formation of argic horizons in the sedimentary layers has been documented at the base of one of the profiles. The peaks of sedimentation correspond to the Migration Period and the early mediaeval Slavic colonization, both rarely identified depositional eras in Central Europe. In contrast, the colluvial layers representing the High Middle Ages and the recent redistribution of material are less represented. The remoteness of the area, the later onset of human pressure on the landscape and the specific nature of the Luvisols in terms of erosion vulnerability have been identified as the main reasons for this sedimentation history.