Paleoenvironmental reconstruction based on soils buried under Scythian fortification in the southern forest-steppe area of the East European Plain

摘要

Landscape response to Late Holocene climatic cycles is based on detailed hierarchical morphological, analytical and micro-biomorphic research of a soil chronosequence which included a soil buried under a fortification earth wall of the Early Iron Age (Luvic Chernozem) and a surface soil (Chernic Greyzemic Luvic Phaeozem) in the southern forest-steppe area of the East European Plain. Both soils formed on similar surfaces with the same lithology (non-carbonate loess underlain by carbonate loess), at the same elevation, and in close proximity to each other. The buried soil was truncated by at 40 cm and transformed by diagenesis. Taking this into account it was possible to reconstruct the soil formed by the time of burial under the earth wall and to classify it as (Chernic) Luvic Phaeozem. Both surface and buried soils are polygenetic combining the features of humid (forest?) and steppe pedogenesis. The radiocarbon data obtained from the Humic horizon of the buried soil (6750 +/- 120 years CalBP) allows bracketing the steppe environment to the mid-Holocene (Atlantic period). Pedogenetic evolution since the Early Iron Age included the next stage of clay illuviation (formation of thin hypo-coatings.) and the development of Greyzemic features. The studied Phaeozems indicate relative landscape stability at the southern boundary of the forest-steppe zone.