Mascall Formation
| Mascall Formation | |
|---|---|
| Stratigraphic range: Hemingfordian-Barstovian ~ | |
Outcrop near Picture Gorge | |
| Type | Sedimentary |
| Underlies | Rattlesnake Formation |
| Overlies | John Day Formation |
| Area | John Day Valley, Fox Basin |
| Thickness | 2,000 feet (610 m) |
| Lithology | |
| Primary | Sandstone, conglomerate |
| Location | |
| Extent | eastern Oregon |
| Type section | |
| Named for | Mascall Ranch (south of Dayville) |
| Named by | J. C. Merriam |
| Year defined | 1901 |
The Mascall Formation is a Miocene geologic formation found along the John Day River Valley of Oregon, in the Western United States.