| Author: | Illinois State Geological Survey |
| Subject: | QE, Geology -- Illinois, Geology -- Illinois -- Maps |
| Format: | Text |
| Date issued: | 2021 |
| Language: | English |
| Publisher: | Project Gutenberg, |
| Rights: | Public domain in the USA. |
| Download link: | Guide to the Geologic Map of Illinois [electronic resource] / Illinois State Geological Survey |