The lower part of the Bt horizon has hue of 10YR or 2.5Y, value of 4 through 6, and chroma of 2 through 4. Clay content ranges from about 32 to 38 percent. Mottles in the Bt horizons commonly have chroma of 4 through 8, but some pedons contain considerable mottles of 2 chroma. The C horizon is silty clay loam or silt loam. These are the Gymer , Oska , Polo , Sharpsburg , and Wenona of the same family and the Grundy , Ladoga , Mahaska , and Tama series.
Gymer soils have redder B horizons.
Oska soils have a lithic contact at depths of less than 40 inches. Polo soils have redder hues in the lower part of the B horizon, Sharpsburg soils have more organic coatings in the upper part of the B horizon and total amounts of phosphorus and potassium are greater. Wenona soils have less silt and more sand and clay in the lower parts of the B horizon which formed in part in clayey glacial till or lacustrine sediments. Grundy soils have more mottles in the upper part of the B horizon, and the B horizon contains more clay. Ladoga soils have A horizons that are thinner or lighter colored or both, and have E horizons.