Atkinson and Plattville soils lack 5YR or redder hue in the lower sola. Calmar, Rockton, and Sibleyville soils have a lithic or paralithic contact at depths less than 40 inches. Hitt soils are on gently undulating to rolling till plains and moraines which are partially controlled by underlying limestone bedrock. Slope gradient ranges from 1 to 12 percent. These soils formed in Late Sangamon paleosols formed in sandy loam, loam, or clay loam Illinoian glacial till and residuum from weathered limestone bedrock, except the upper 10 to 25 inches above the IIB is formed in loess.
Summers are hot and winters are cold.
Mean annual temperature is between 45 and 57 degrees F, and mean annual precipitation ranges from 28 to 40 inches. Ogle or Tama soils commonly occur on ridgetops upslope from the Hitt soils where the loess is thicker. Durand and Winnebago soils occur in many places with Hitt soils in similar side slope positions, where the drift is thicker. Dodgeville soils occur on steeper slopes or on similar slopes where glacial deposits do not occur above the bedrock. Hitt is the dark colored member of a biosequence containing Oneco and Woodbine series.