Ludlow Formation
| Ludlow Formation | |
|---|---|
| Stratigraphic range: Paleogene | |
| Jarosite concretions from the Ludlow Formation (South Dakota) | |
| Type | Formation | 
| Unit of | (partially) Fort Union Formation | 
| Underlies | Cannonball Formation and Slope Formation | 
| Overlies | Hell Creek Formation | 
| Location | |
| Region | North Dakota, South Dakota | 
| Country | United States | 
The Ludlow Formation is a geologic formation in western North Dakota. It preserves fossils dating back to the Paleogene Period.