| Blue River Group | |
|---|---|
| Stratigraphic range: Carboniferous | |
| Type | Group |
| Sub-units |
|
| Lithology | |
| Primary | Limestone |
| Other | Shale, Sandstone, Gypsum, Chert |
| Location | |
| Region |  Illinois |
| Country |  United States |
| Type section | |
| Named for | The Blue River |
The Blue River Group is a geologic group in Illinois. It preserves fossils dating back to the Carboniferous period.