Buried soils of defence lines of ancient Russia and the problems of ancient and recent history of soil formation.

摘要

A typical chernozem buried under the rampart of the Kama defence line of the Russian Empire in the mid 17th century was studied. The properties of this soil are compared with the properties of surface chernozems in surrounding landscapes. It is shown that soil properties have changed little within the past 350 years. However, the downward migration of carbonates has led to a 10% decrease in the total pool of soil carbonates within the 2-m-thick layer. At the same time, accumulation of easily soluble salts and gypsum in the 100-200 cm layer was observed; this is related to the upward migration of salts from the parent rock. Both the leaching of carbonates and the accumulation of easily soluble salts can be explained by climatic fluctuations duringthe last four centuries. An original chronological scheme of soil formation during the Holocene is suggested. It includes the prehistoric period (12-5 ka BP), the ancient period (from the third millennium BC to the fourth century AD), the medieval period(from the fifth to the 16th century AD), and the recent period (the last 300-400 years).