Grantsburg and Hosmer soils average less than 10 percent sand to a depth of 60 inches. Lawrenceville soils have rock fragments in the upper part of the series control section. Omulga, Otwell, and Rainsboro soils have subhorizons in the lower part of the series control section that have as much as 50 percent sand. Sadler soils have as much as 30 percent fragments of siltstone or sandstone in the fragipan. Weisburg soils have a paralithic contact in the series control section.
Zanesville soils have a lithic contact in the series control section.
Ava soils are on convex ridges, shoulders and backslopes on loess-covered dissected till plains. Slope gradients are 0 to 18 percent. The underlying deposits contain more sand than the overlying loess mantle and consist of erosional sediments or reworked material of the A horizon of the paleosol and an admixed amount of earliest Wisconsinan loess. Locally these soils contain a band of pebbles of the Illinoian till concentrated by erosion. Ava soils are underlain, at a depth of about 4 to 7 feet, by a strongly developed paleosol considered to be from the Illinoian till stage.