Scherr Formation
| Scherr Formation Stratigraphic range: Late Devonian | |
|---|---|
| Type | sedimentary |
| Unit of | Greenland Gap Group |
| Sub-units | Minnehaha Springs Member |
| Underlies | Foreknobs Formation |
| Overlies | Brallier Formation |
| Thickness | 1004 ft at type section |
| Lithology | |
| Primary | shale |
| Location | |
| Region | Appalachian Mountains |
| Extent | Pennsylvania, Maryland, Virginia, West Virginia |
| Type section | |
| Named for | Scherr, West Virginia |
| Named by | J. M. Dennison, 1970 |
The Devonian Scherr Formation is a mapped bedrock unit in Pennsylvania, Maryland, Virginia and West Virginia.
Description
The Scherr Formation consists predominantly of siltstone and shale. Lower part of unit includes considerable fine-grained sandstone, while upper two thirds contains almost no sandstone. It weathers light olive gray.[1]
Stratigraphy
Dennison (1970) renamed the old Chemung Formation the Greenland Gap Group and divided it into the lower Scherr Formation and the upper Foreknobs Formation. De Witt (1974) extended the Scherr and Foreknobs into Pennsylvania, but did not use the term Greenland Gap Group.[2]
Boswell, et al. (1987), does not recognize the Scherr and Foreknobs Formations in the subsurface of West Virginia and thus these formations are reduced from "group" to "formation" as the Greenland Gap Formation.[3]
The Minnehaha Springs Member is a "clastic bundle" consisting of interbedded medium gray siltstone and olive gray shale with some grayish-red siltstone and shale and some sandstone. It is interpreted as turbidites.[4] This same member is proposed to exist at the base of the Scherr's lateral equivalent, the Lock Haven Formation.[5]
Notable Exposures
- Type section: along WV Highway 42, Grant County 39°11′45″N 79°10′48″W / 39.19583°N 79.18000°W
Age
Relative age dating places the Scherr in the late Devonian.
References
- ↑ Dennison, J.M., 1970, Stratigraphic divisions of Upper Devonian Greenland Gap Group ("Chemung Formation") along Allegheny Front in West Virginia, Maryland, and Highland County, Virginia: Southeastern Geology, v. 12, no. 1, p. 53-82.
- ↑ de Witt, Wallace, Jr., 1974, Geologic map of the Beans Cove and Hyndman quadrangles and part of the Fairhope quadrangle, Bedford County, Pennsylvania: U.S. Geological Survey Miscellaneous Investigations Series Map, I-801, 6 p., 1 sheet, scale 1:24,000
- ↑ Boswell, R.M., Donaldson, A.C., and Lewis, J.S., 1987, Subsurface stratigraphy of the Upper Devonian and Lower Mississippian of northern West Virginia: Southeastern Geology, v. 28, no. 2, p. 105-131.
- ↑ Lyke, W.L., 1986, The stratigraphy, paleogeography, depositional environment, faunal communities, and general petrology of the Minnehaha Springs Member of the Scherr Formation: Southeastern Geology, v. 26, no. 3, p. 173-192.
- ↑ Warne, A.G., and McGhee, G.R., Jr., 1991, Stratigraphic subdivisions of the Upper Devonian Scherr, Foreknobs, and Lock Haven Formations near the Allegheny Front of central Pennsylvania: Northeastern Geology, v. 13, no. 2, p. 96-109.