Helderberg Group

Mostly cherty limestone, with some sandstone and shale. Contains several named stratigraphic units, including the Keyser Formation, which is partly Silurian and includes the Clifton Forge Sandstone and Big Mountain Shale Members.
State West Virginia
Name Helderberg Group
Geologic age Devonian
Lithologic constituents
Major
Sedimentary > Carbonate > Limestonemostly cherty limestone
Minor
Sedimentary > Clastic > Sandstone
Sedimentary > Clastic > Mudstone > Shale
Comments Includes: Rocky Gap Sandstone (USGS) used on Southeastern columnar section. Thickness: Northeastern 350-445 ft, Western 210 ft, Southeastern 0-50 ft, Southeastern - Rocky Gap Sandstone 175 ft.
References

Cardwell, D.H., Erwin, R.B., and Woodward, H.P., 1968 (slightly revised 1986), Geologic Map of West Virginia: West Virginia Geological and Economic Survey, Map 1, East Sheet, scale 1:250,000.

NGMDB product
Counties Grant - Greenbrier - Hampshire - Hardy - Mineral - Pendleton - Pocahontas