Illinois Geologic Quadrangle (IGQ) Maps

Illinois Geologic Quadrangle maps were originally produced as STATEMAP or Illinois Preliminary Geologic Map products, or were derived from other mapping activity. In addition to bedrock and surficial geology, this series may include a variety of geologic themes such as bedrock topography, drift thickness, and others. IGQ maps are available for sale as hard copy and as free downloadable graphics through this website. They are extensively reviewed internally and externally, and comply with ISGS cartographic standards at the time of public release.

The image at the right shows the IGQ mapped areas.

Not shown on map
Bandana, Brownfield, Cairo, Columbia, Crab Orchard, Crab Orchard Lake, Carrier Mills, Hampshire, Herrin, Johnston City, Joppa, Karnak, Marion, Mascoutah, Mt. Pleasant, Pittsburg, Renault, Waterloo, Welge