Thanks to the Glaciers
Dr. Edward Runge>LPL Interviews N-Z>LPL Interviews K-Z, Segment 6
- Discussion of Illinois soils. Soils of central Illinois are dark, either thick layer of loess or thin loess over Wisconsin glacial till. Latter shows a moraine in Shelbyville that marks the edge. Loess cap is about four feet deep. Gray southern soils are weathered pre-Wisconsin surface, north soils on calcium carbonate bed. Soils on acid substrate weather faster and lose fertility. Time is 20,000 years ago.