It averages 10 to 18 percent clay and 15 to 20 percent sand. Reaction is very strongly acid or strongly acid. Texture is silt loam or silty clay loam and averages 24 to 30 percent clay and 10 to 15 percent sand. Reaction is extremely acid or very strongly acid. Reaction ranges from extremely acid to strongly acid.
Reaction ranges from strongly acid to neutral.
There are no competing series. Avonburg soils are on summits of loess-covered till plains. Slopes range from 0 to 6 percent. They formed in 60 to 90 inches of loess and the underlying paleosol in Illinoian till. The upper 20 to 40 inches of loess averages about 15 percent sand, and the lower loess averages about 24 percent.