On the relationship between pedogenic and lithogenic carbonates and their dynamics in the profile of steppe soils during the last 4000 years

The proportion of pedogenic carbonates varies in different types of steppe soils developing from alluvial, colluvial, and covering loess deposits cont aining limestone debris; it constitutes 40-50% of the total content of carb onates in ordinary chernozems, 30-40% in dark chestnut soils, and 20-30% in light chestnut soils. The rate of accumulation of pedogenic carbonates in steppe soils varies from 1.14 to 9.3 g/m(2) per year, being most active dur ing the periods of aridization of the climate.