Blackleaf Formation
| Blackleaf Formation | |
|---|---|
| Stratigraphic range: late Albian-Cenomanian ~ | |
| Type | Formation | 
| Unit of | Colorado Group | 
| Lithology | |
| Primary | Mudstone, sandstone | 
| Other | Shale, siltstone | 
| Location | |
| Coordinates | 44°30′N 112°36′W / 44.5°N 112.6°W | 
| Approximate paleocoordinates | 45°54′N 72°18′W / 45.9°N 72.3°W | 
| Region | Montana | 
| Country | United States | 
The Blackleaf Formation is a geologic formation in Montana. It preserves fossils dating back to the Albian to Cenomanian stages of the Cretaceous period.