These soils formed in colluvium derived from arkose, graywacke or quartzite. The mean annual air temperature is about 56 degrees F. and mean annual precipitation is about 41 inches near the type location. These are the Ditney , Unicoi , and Maymead soils. Ditney and Unicoi soils, on higher lying slopes and are less than 40 inches deep to bedrock. Maymead soils in similar positions do not have an argillic horizon.
Permeability is moderate in the subsoil and moderate to moderately rapid in the substratum.
Runoff class is low on gentle slopes, medium on strong or moderately steep slopes, and high on steeper slopes. Most areas of this soil are forested. A few areas are cleared and used for pasture and cultivated crops. The native vegetation is upland oaks and yellow poplar. The Southern Appalachian Mountains of Tennessee, North Carolina and Virginia and possibly Georgia.