Impact of aeolian processes on peat accumulation: Late Glacial–Holocene history of the Hamernia peat bog (Roztocze region, south-eastern Poland)

The Hamernia peat bog in the Roztocze region started to develop in the Allerød within the deflation basin divided into two sub-basins by a parabolic dune formed in the Older or the Oldest Dryas. Lithological and palynological analyses as well as radiocarbon dating of samples from three logs cored in different parts of the peat-bog indicate that up to the Subatlantic, when the top of the dune bar was inundated, the evolution of both sub-basins was different in hydrological and sedimentological aspects. Aeolian processes were active in the Younger Dryas, generating delivery of mineral material to both sub-basins. However, the intensiveness of this process was much lower than in earlier cold phases, as indicated by the limited spatial and temporal delivery of this material (restricted mainly to the wind-ward sub-basin). The nature of the next short episode of mineral material delivery to one sub-basin, recorded during the climate cooling at the turn of the Boreal and the Atlantic Phases, is not clear. Local aeolian or slope processes (water erosion accompanied by mass movements) are suspected to be responsible for this episode. The youngest stage of slight but continuous mineral material delivery, caused by aeolian processes, started in the climate cooling at the beginning of the Subatlantic, and was contemporary with the intensification of human activity in this area. The geological history in the Late Vistulian and the Holocene suggests that the last dune-forming stage in this area occurred during the Older Dryas.