The Chester Formation is a geologic formationinIllinois. It preserves fossils dating back to the Carboniferous period.
| Chester Formation | |
|---|---|
| Stratigraphic range: Carboniferous | |
| Type | Formation |
| Location | |
| Region |  Illinois |
| Country |  United States |
 | This article about a specific stratigraphic formation in Illinois is a stub. You can help Wikipedia by expanding it. |
