| Clinton Group Stratigraphic range: Late Silurian |
|
|---|---|
Rocks of the Clinton Group on the east face of Schuylkill Gap |
|
| Type | sedimentary |
| Sub-units | Rochester Shale, Rose Hill Formation, Keefer Formation |
| Underlies | Bloomsburg Formation |
| Overlies | Tuscarora Formation |
| Thickness | 1640 ft |
| Lithology | |
| Primary | sandstone |
| Other | shale |
| Location | |
| Region | Appalachian Mountains |
| Country | United States |
| Extent | Pennsylvania, Maryland, New York, West Virginia |
The Silurian Clinton Group is a mapped bedrock unit in New York, Pennsylvania, Maryland, and West Virginia. It contains the Rochester Shale, Rose Hill Formation[1] and the ridge-forming Keefer Formation.[2] Other names for the members are Reynales Limestone, Williamson Shale, Irondequoit Limestone, and Rochester Shale[2]
Contents |
The Clinton Group is defined as a brownish-gray to olive-gray shaly claystone, and a thinly-bedded, fine-grained sandstone, with dark red, fine-grained “iron” sandstone also present. It is approximately 1640 feet thick.[1] The Rochester Shale is a gray, thin-bedded calcareous shale and dark gray, thin- to medium-bedded lenticular limestone. The Keefer Sandstone is a white to yellowish-gray, thick-bedded protoquartzite and orthoquartzite. The Rose Hill Formation is olive-gray to drab, thin-bedded sandstone.[3] The Keefer sandstone has limestone-like properties, because it contains calcite and fossils in addition to quartz.[4]
In Maryland, the Rose Hill Formation contained the Cresaptown Iron Sandstone.[3]
Relative age dating of the Clinton Group places it in the Lower Silurian period. It rests conformably atop the Tuscarora Formation and conformably below the Lower and Upper Silurian Lockport Group[2] and Bloomsburg Formation.[1]