Middlesex Formation
| Middlesex Formation | |
|---|---|
| Stratigraphic range: Frasnian | |
| Type | Formation |
| Unit of | Sonyea Group |
| Underlies | Cashaqua Shale or Pulteney shale |
| Overlies | Genesee Group |
| Thickness | 6–75 feet (23 m) |
| Lithology | |
| Primary | Black Shale |
| Location | |
| Region | Maryland, New York, Ohio, Pennsylvania, West Virginia |
| Country | United States |
| Type section | |
| Named for | Town of Middlesex, NY |
The Middlesex Formation is a carbon rich black shale geologic formation found in the Appalachian Basin. It represents one of several transgressive events (rising sea levels) during the Late Devonian.