Juniata Formation
| Juniata Formation | |
|---|---|
| Stratigraphic range: Late Ordovician | |
Outcrop on U.S. Route 522 at Blacklog Narrows southeast of Orbisonia, Pennsylvania. | |
| Type | sedimentary |
| Underlies | Oswego Formation and Tuscarora Formation |
| Overlies | Bald Eagle Formation |
| Thickness | 400–1,125 ft (122–343 m) |
| Lithology | |
| Primary | sandstone, siltstone, shale |
| Location | |
| Region | Appalachian Mountains |
| Extent | Maryland, Pennsylvania, Tennessee, Virginia, and West Virginia |
| Type section | |
| Named for | Juniata River in Pennsylvania |
| Named by | Darton and Taff |
The Ordovician Juniata Formation is a mapped bedrock unit in Pennsylvania, West Virginia, Virginia, Tennessee, and Maryland. It is a relative slope-former occurring between the two prominent ridge-forming sandstone units: the Tuscarora Formation and the Bald Eagle Formation in the Appalachian Mountains.