Soils of a medieval burial mound as a paleoenvironmental archive (Leningrad region, Northwest Russia)

Investigations of the composition of the buried soils formed on the surface of the kame hill (the northwestern part of the East European Plain, Leningrad region) to which the medieval Izhora burial mound was tied showed that the original soil cover was represented by combinations of automorphic Entic (and/or Albic) Podzols (Lamellic, Arenic). These soils are also characteristic of modern biogeocenoses, which indicates a practically changeless trend of pedogenesis in the average time interval. It was determined that during the construction of the mound and leveling of its surface the soil cover was scalped to a significant degree. The diagenetic changes in soils during the time of their burial (~800 years) were determined. Based on the data of phytolith and spore-pollen analyses it was shown that the original coniferous forest was cut down, partly burnt. Then the site with ash was plowed for cereal crops. After a short time, when the fertility of the soil had decreased, the site was abandoned and began to overgrow with forest (from small-leaved species to coniferous). At this stage, the forest was rebuilt for burial mounds.