| Black River Formation Stratigraphic range: Middle Ordovician |
|
|---|---|
| Type | Formation |
| Underlies | Trenton Formation |
| Overlies | Au Train Formation |
| Location | |
| Region | Quebec and Michigan |
| Country | Canada and the United States |
The Black River Formation is a geologic formation in Quebec, Canada and Michigan, United States. It preserves fossils dating back to the Ordovician period.