Late Vistulian and Holocene development of litho-morpho-pedogenic processes in the southern Baltic coastal zone: A case study from Dębina, northern Poland

Abstract

The study aimed to reconstruct major phases of the litho-morpho-pedogenic processes in the southern Baltic coastal zone near Dębina in northern Poland. Five profiles of fossil soils in the coastal cliff were described, sampled and analysed using standard procedures. The studied outcrop covers a sequence of deposits, including the basal till of the Świecie Stadial (MIS 4) of the Vistula Glaciation, the ablation till of the Pomeranian Phase (MIS 2) of the Vistula Glaciation, the thin cover of glacilimnic sand, the lacustrine sediments filling the palaeolake basin, and aeolian deposits of varied age. A sequence of paleosols developed successively within these deposits during the Late Vistulian and Holocene (MIS 1). The initialization of soil-forming processes occurred under the influence of periglacial environment and pioneer tundra vegetation. Endostagnic Podzols (Abruptic, Epiarenic, Endoloamic, Endodensic) developed within the plateau, and they have some features typical for periglacial environments (e.g. the presence of a cryoilluvial horizon, the poor humification of soil organic matter, the low abundance in N and P, and the vertical displacement of P). The basin of a small lake has been filled successively with sediments and Dystric Endocalcaric Katostagnic Fluvisols (Arenic, Humic, Endolimnic) developed from these sediments during the Late Vistulian and Early Holocene. The previously mentioned soils were buried by sandy cover in the Early Subatlantic due to intensification of aeolian processes. Ortsteinic Podzols (Pantoarenic) developed within a newly formed sandy cover. A fossil fireplace preserved in the top of these soils constitutes evidence of human activity dating back almost 2000 years. Ortsteinic Podzol (Pantoarenic) are dissected by a dry valley that developed as a result of some fluvial episode, perhaps induced by human activity. It was subsequently filled with aeolian sands, and Dystric Arenosols (Aeolic, Ochric) developed within them. Ortsteinic Podzol (Pantoarenic) and Dystric Arenosols (Aeolic, Ochric) were buried approximately five centuries ago. Our findings for the studied cliff section correlate well with results of other authors concerning the postglacial dynamics of morphogenetic processes. The studies provide significantly enriched geomorphological knowledge related to the formation of relief in the study area, with pedological aspects.