The Concept of “Buried” Versus “Isolated” Paleosols:

Examples from Northeastern Kansas

 

Randall J. Schaetzl and C. J. Sorenson

 

            This paper offers an alternative to the current definition of a buried soil (Soil Survey Staff 1975), stressing criteria that are more amenable to paleopedology.  We suggest that any measurable depth of sediment buries a soil and that the soil remains buried until pedogenesis “welds” the overlying sediment to the buried solum.  Complete welding is accomplished when no observable material, interpreted taxonomically as a C horizon, is present between the buried and burying profiles.  A special type of buried soil, the isolated paleosol, is not currently affected by surface pedogenic processes.  The lower limit of these surficial processes is called the depth of isolation.  All isolated paleosols are buried below this depth, which varies depending upon local conditions.  We present a theoretical model that uses paleosol characteristics to predict the depth of isolation.  Data from 29 buried and exhumed paleosols in Kansas suggest that isolated paleosols do exist, although at greater depths than originally anticipated.