Llewellyn Formation
| Llewellyn Formation | |
|---|---|
| Stratigraphic range: Late Pennsylvanian ~ | |
A hand sample of the bottom of the Llewellyn from St. Clair, Pennsylvania | |
| Type | Sedimentary |
| Unit of | none |
| Sub-units | none (most economic coal beds are named) |
| Overlies | Pottsville Formation |
| Thickness | up to 1,500 feet (460 m) |
| Lithology | |
| Primary | Sandstone |
| Other | Shale, Conglomerate, Coal |
| Location | |
| Region | Appalachian Basin of eastern North America |
| Extent | Anthracite fields of Pennsylvania |
| Type section | |
| Named for | Llewellyn, Pennsylvania |
| Named by | G. Wood, 1964 |
The Llewellyn Formation is a mapped bedrock unit in eastern Pennsylvania. It was previously known as the "coal measures" and the post-Pottsville rocks. The formation is named for the community of Llewellyn in Schuylkill County.