Unraveling Mediaeval human traces in fluvial deposits of the Dyje River near the Pohansko stronghold (Czech Republic)

Sedimentological, archaeological, geochemical and pollen analyses combined with numerical dating were employed to examine the fluvial deposits of the Dyje River within the immediate vicinity of the Pohansko stronghold (Moravia, Czech Republic). This comprehensive approach facilitated the reconstruction of the chronology and nature of the processes in both the Dyje River catchment and its floodplain, mostly during the Medieval period. The older overbank deposits accumulated during the Late Holocene sometime before the 9th century CE. Palaeochannel sands were deposited between the 9th and 11th centuries CE as the infill of one fluvial channel of the Dyje River. The lower part of these sands displays direct traces of human intervention, including stones interpreted as from pavements and a wooden construction dated between 894 and 914 CE. The wooden construction may represent the remains of a bridge, a device for fish capture or a wooden structure. Geochemical signals associated with human activities are elevated in the palaeochannel sands, in part contemporary with the settlement activities at the Pohansko stronghold. Anthropogenic pollen indicators indicate the highest intensity of agriculture in the river catchment also in this period. After abandonment of the channel, the younger upper overbank deposits accumulated after the 11th century CE.