Illinois Preliminary Geologic Map (IPGM)

Many Illinois Preliminary Geologic Quadrangle geologic maps were originally 1:24,000-scale STATEMAP products, but the series may include maps of other scales and funding sources. In addition to bedrock and surficial geology, this series may include a variety of geologic themes such as bedrock topography, drift thickness, and others. Some IPGMs will be upgraded to the Illinois Geologic Quadrangle series. IPGM maps are available for sale as hardcopy and as free downloadable graphics through this website. They receive a brief internal scientific review and editing, and comply with ISGS cartographic standards at the time of public release.

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Chillicothe, Fishhook, Dunlap, Kellervlle, Lacon, Monks Mound, Murphysboro, Oakhill, Pomona, Putnam