Illinois County Geologic Maps (ICGM)

The Illinois County Geologic Map (ICGM) series was initiated in 2007. This series may include a variety of geologic themes, such as bedrock geology, surficial geology, geologic cross sections, three-dimensional models, major Quaternary aquifers, aquifer sensitivity to contamination, and others. ICGM series maps are available for sale as hard copy and as free downloadable graphics through this Web site. The maps in this series are extensively reviewed internally and externally and comply with ISGS cartographic standards at the time of public release.

The map at the right shows the completed areas.