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CHERNOZEMS, BURIED SOILS, AND LOESSES OF THE RUSSIAN PLAIN: THEIR AGE AND GENESIS

The evolution of concepts of genesis of the present-day Chernozems and of underlying loesses and paleosols is reviewed. Dokuchaev challenged the view that the Chernozems of the Russian Plain were formed in wetlands. He showed them to be in equilibrium with the modern elimate and native vegetation. Recent dating of soil organic matter suggests that the considerable thickness of Chernozems profiles may be a result of loess increments during pedogenesis. The idea that paleosols in the underlying loesses were once Chernozems has been disproved. There is a need for detailed comparison of both modern soils and paleosols of the Russian Plain with their counterparts in North America.