Soil genesis and classification of the high stream terraces on the Eastern Highland Rim in Tennessee

Soils occurring on the ancient high stream terraces on the Eastern Highland Rim in Tennessee were investigated for their genesis and classification. Five sites were chosen for sampling based on the similarity of the landscapes and on the presence of krotovinas at each site. The krotovinas are believed to be the remains of ancient crayfish (Cambarus fodiens) burrows. The soils occurring on the five sites were described in the field, to a depth in excess of 5 meters, and analyzed for particle size distribution, cation exchange capacity, total carbon, dithionite extractable iron, hydroxylamine manganese, exchangeable bases, and clay and sand mineralogy. The soils were subsequently classified according to Soil Taxonomy. The soils classified at the Great Group level as Paleudults, Hapludalfs, and Paleudalfs.

All soils in this study formed in a parent material sequence of loess over alluvium. The loess is believed to be of local origin and approximately 10,000 years old or younger. The alluvium was deposited by an ancient stream system that was once active in this region of the Eastern Highland Rim. The disappearance of the stream that deposited this material is believed to be caused by a combination of stream meandering and stream piracy. The paleosol that formed in the alluvial deposits is approximately 500,000 years old (mid-Pleistocene). The entire region is underlain, geologically, by Mississippian limestone of the St. Louis formation.