Casselman Formation
| Casselman Formation | |
|---|---|
| Stratigraphic range: Pennsylvanian | |
Outcrop of Casselman Formation at Mile Marker 84.2, Pennsylvania Turnpike | |
| Type | sedimentary |
| Unit of | Conemaugh Group |
| Underlies | Monongahela Group |
| Overlies | Glenshaw Formation |
| Lithology | |
| Primary | shale, siltstone, sandstone, red beds, coal |
| Other | limestone |
| Location | |
| Region | Appalachian Plateau |
| Country | United States |
| Extent | Ohio, Pennsylvania, Maryland, West Virginia |
| Type section | |
| Named for | Casselman River |
| Named by | N. K. Flint, 1965 |
The Casselman Formation mapped sedimentary bedrock unit in Pennsylvania, Maryland, and West Virginia, of Pennsylvanian age. It is the uppermost of two formations in the Conemaugh Group, the lower being the Glenshaw Formation. The boundary between these two units is the top of the marine Ames Limestone. The Conemaugh Group overlies the Upper Freeport coal bed of the Allegheny Formation and underlies the Pittsburgh coal seam of the Monongahela Group.