Soil Evolution and Climate Dynamics in the Steppes of South-East Russian Plain within the Neolith and Bronze Epochs (IV–II MIL. BC)

Abstract

Main regularities of the development of soils of dry and desert steppes of drained landscapes on southeast Russian plain have been established basing on studies of under-kurgan pedochronosequences (6000– 3000 years ago). During IV–III mil. BC soil evolution occurred on the subtype level with shifts of soil subzones boundaries towards the north. Each of natural regions studied (Srednerusskaya, Yergeninskaya uplands, Cis-Caspian lowland) clearly demonstrated strengthening of climate aridization in the second half of III mil. BC. It had led to convergence of soil cover with transformation of dark-chestnut, chestnut, and light-chestnut soils into chestnut-like semidesert ones, which dominated in the region within the time-window 4200–3900 years ago. In the fi rst half of II mil. BC the next change of conditions of soil formation provoked by an increase of the rate of atmospheric humidity had started. It had conditioned the divergence of soil cover with secondary formation of areas of zonal chestnut soils and solonetzes on the places of chestnut-like ones by the middle of II mil. BC. The data obtained allow us to consider that the age of modern chestnut solonetz complexes in the region does not exceed 3500 years.