| Potosi Formation | |
|---|---|
| Stratigraphic range: Cambrian | |
| Fossil from the Potosi Dolomite | |
| Type | Formation |
| Underlies | Eminence Dolomite and Oneota Dolomite |
| Overlies | Davis Formation, [1] Derby-Doerun Dolomite, [2] and Franconia Formation |
| Location | |
| Coordinates | 38°05′30″N90°41′07″W / 38.091733°N 90.685176°W |
| Region | Illinois, Indiana, Missouri |
| Country | United States |
The Potosi Formation is a geologic formation in Missouri, Illinois and Indiana. It preserves fossils dating back to the Cambrian period.