Brown Forest, Polygenetic, and Congeliturbate Profiles of Potter County, Pennsylvania

A Brown Forest soil, soils having polygenetic profiles, and soils believed to have developed in materials formed by frost action and slope creep were mapped in Potter County, Pa., an area of normally well developed Podzol soils. Because of the complex conditions which existed at the margins of the continental glaciers, soil classification is difficult in these areas. Field observations and the following laboratory analyses were made: mechanical analyses, pH determinations, X‐ray diffraction analyses, and exchangeable cation and base saturation determinations. The results show that the outstanding characteristics of the Brown Forest great soil group can be identified in units as small as a single soil type. The Brown Forest profile has a characteristic granular structure, brown color, and a variation in pH from nearly neutral to acid to alkaline from the surface downward. The presence of gibbsite, usually associated with tropical weathering, in the lower part of the Sweden (tentative) series suggests that it is of polygenetic nature and that the lower part of the profile formed prior to Wisconsin glaciation. The physical and chemical analyses of the congeliturbate profiles, as well as a lack of erratics and rounded sands and gravels, suggest that although till‐like in nature, such profiles may have developed in materials formed as a result of frost action rather than glacial action. Further study is needed to substantiate this hypothesis.