Pedochronosequences of Medieval Burial Mounds, Pskov Oblast

The soils buried under the early medieval mounds of the 9th and early 11th centuries AD were studied. The reconstruction of environmental trendу and their influence on soils was carried out on the basis of a comparative analysis of the properties of soils buried under mounds of different ages, surface soils, and newly formed soil on mound structures supplemented with data on the time of soil formation on sandy parent rocks in the taiga zone. The study area belongs to the Baltic province of soddy-podzolic soils of the southern taiga subzone. Soils buried under mound structures characterize periods with different climatic conditions. Soils that developed before burial in the cool and humid climate of the 8th–9th centuries AD are specified by the mobility of iron compounds in the profile and a morphologically pronounced accumulation of bleached quartz grains in its upper part. The influence of relatively warm and dry climate of the 10th century AD on the processes of soil formation is manifested in the lower mobility of iron compounds, more active humus accumulation, and less pronounced bleaching of mineral grains. The time of formation of the profile of soddy podbur in the material of mound structures was estimated at 1000 years. The construction of the mound structures consisted in successive filling of the mound from the edges to the center of the site, so that the material of middle horizons of the initial natural soil turned out to be in the upper part of the mound.