USGS Home
Contact USGS
Search USGS

Mineral Resources > Online Spatial Data > Geology > by state > West Virginia Geology

Geologic units in Pocahontas county, West Virginia

[Additional scientific data in this geographic area]

Oriskany Sandstone and Huntersville Chert (Devonian) at surface, covers < 0.1 % of this area

Oriskany Sandstone and Huntersville Chert - Oriskany Sandstone: sometimes designated Ridgeley in eastern West Virginia. White to brown coarse- to fine-grained, partly calcareous sandstone, locally pebbly or conglomeratic, and ridge-forming. May be white, nearly pure silica, and a source of glass sand, as at Berkeley Springs, Morgan County. Huntersville Chert (part of Onesquethaw ("Onondaga") Group): ranges from a nearly pure slightly calcitic or dolomitic chert to an inter-tonguing of such chert and the Needmore Shale. Grades westward in the subsurface to a limestone, commonly considered as "Onondaga". Contains the "glauconitic" Bobs Ridge Sandstone Member. Not mappable at scale of this map. Included with Do.

Lithology: sandstone; chert; limestone

Brallier Formation (Devonian) at surface, covers 6 % of this area

Brallier Formation - predominantly olive-gray to dark, thickly laminated marine shale, with considerable siltstone and thin sandstone lenses; mainly nonfossiliferous.

Lithology: shale; siltstone; sandstone

Millboro Shale (Devonian) at surface, covers 3 % of this area

Millboro Shale - dark grey to black shale facies of eastern West Virginia. Consists of units: Harrell Shale, Mahantango Formation and Marcellus Formation.

Lithology: shale; black shale

Hampshire Formation (Devonian) at surface, covers 13 % of this area

Hampshire Formation - non-marine shales and fine micaceous sandstones, mostly red to brownish-gray, including siltstone, sandstone and conglomerate. Generally distinguishable from the underlying Chemung by non-marine character and red color.

Lithology: shale; sandstone; siltstone; conglomerate

Mauch Chunk Group (Mississippian) at surface, covers < 0.1 % of this area

Mauch Chunk Group - red, green, and medium-gray shale and sandstone, with a few thin limestones.

Lithology: shale; sandstone; limestone

Tonoloway, Wills Creek, and Williamsport Formations (Silurian) at surface, covers 2 % of this area

Tonoloway, Wills Creek, and Williamsport Formations - includes the thin-bedded platy argillaceous limestones of the Tonoloway, the thin-bedded shale with fossiliferous limestones of the Wills Creek, the Bloomsburg red clastic facies, and the greenish-brown to white Williamsport Sandstone. The Wills Creek contains anhydrite and rock salt, the latter supplying brine from deep wells along the Ohio River.

Lithology: limestone; shale; sandstone; clastic; chemical

New River Formation (Pennsylvanian) at surface, covers 7 % of this area

New River Formation (part of Pottsville Group) - predominantly sandstone, with some shale, siltstone, and coal. Grades to nearly all sandstone in the subsurface. Extends from the top of the Upper Nuttall Sandstone to the top of the Flattop Mountain Sandstone. Includes the Iaeger, Sewell, Welch, Raleigh, Beckley, Fire Creek, and Pocahontas Nos. 8 and 9 coals.

Lithology: sandstone; shale; siltstone; coal

Chemung Formation (redefined as Foreknobs Formation) (Devonian) at surface, covers < 0.1 % of this area

Chemung Formation - Shale and sandstone with a few thin, quartz-pebble conglomerates and red-beds.

Lithology: shale; sandstone; conglomerate

Helderberg Group (Devonian) at surface, covers < 0.1 % of this area

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.

Lithology: limestone; sandstone; shale

Pocono Group (Mississippian) at surface, covers 7 % of this area

Pocono Group - predominantly hard gray massive sandstones, with some shale. In the Eastern Panhandle, has been divided into the Hedges, Purslane, and Rockwell Formations.

Lithology: sandstone; shale

McKenzie Formation and Clinton Group (Silurian) at surface, covers 2 % of this area

McKenzie Formation and Clinton Group - includes the McKenzie Formation, consisting of shale with thin limestone lenses; the dark Rochester Shale; the white Keefer Sandstone; and the Rose Hill predominantly red shale, with thin sandstone interbeds, some of which are called "iron sandstones" from their reddish-brown color and hematite content.

Lithology: shale; sandstone; limestone

Bluefield Formation (Mississippian) at surface, covers 12 % of this area

Bluefield Formation (part of Mauch Chunk Group) - red and green shale and sandstone, with a few thin limestone lenses, such as the Reynolds.

Lithology: shale; sandstone; limestone

Kanawha Formation (Pennsylvanian) at surface, covers 4 % of this area

Kanawha Formation (part of Pottsville Group) - sandstone (approx 50%), shale, siltstone, and coal. Contains several marine zones. Becomes more shaly westward in the subsurface. Extends from the top of the Homewood Sandstone to the top of the Upper Nuttall Sandstone. Includes the Stockton (Mercer), Coalburg, Winifrede, Chilton, Williamson, Cedar Grove, Alma, Peerless, Campbell Creek, Powellton, Eagle, Gilbert, and Douglas coals.

Lithology: sandstone; shale; siltstone; coal

Juniata and Oswego Formations (Ordovician) at surface, covers < 0.1 % of this area

Juniata and Oswego Formations - the Juniata is a thin-bedded, blocky, red sandstone and shale. In places it is underlain by the thick-bedded, gray Oswego Sandstone.

Lithology: sandstone; shale

Greenbrier Group (Mississippian) at surface, covers 7 % of this area

Greenbrier Group - marine limestone and marine and non-marine red and gray shale, and minor sandstone beds in numerous formational units.

Lithology: limestone; shale; sandstone

Hampshire Formation (Devonian) at surface, covers 0.1 % of this area

Hampshire Formation - Dusky-red to grayish-red shale, mudrock, and sandstone.

Lithology: sandstone; limestone; shale

Pocahontas Formation (Pennsylvanian) at surface, covers < 0.1 % of this area

Pocahontas Formation (part of Pottsville Group) - sandstone, approx. 50%, with some shale, siltstone, and coal. Extends from the top of the Flattop Mountain Sandstone to the top of the Mississippian. Includes from bottom upward Pocahontas coals Nos. 1 through 7.

Lithology: sandstone; shale; siltstone; coal

Chemung Group (Devonian) at surface, covers 21 % of this area

Chemung Group - gray to brown siltstone and sandstone with shale and conglomeratic interbeds; mainly marine and sparingly fossiliferous; boundaries gradational. Can be divided into the Voreknobs and Scherr Formations along the Allegheny Front. Parkhead Sandstone Member near base.

Lithology: siltstone; sandstone; shale; conglomerate

Hinton Formation (Mississippian) at surface, covers 7 % of this area

Hinton Formation (part of Mauch Chunk Group) - red, green, and medium-gray shale and sandstone, with a few thin limestone beds, including the Avis.

Lithology: shale; sandstone; limestone

Oriskany Sandstone and Helderberg Group, undivided (Devonian) at surface, covers 2 % of this area

Oriskany Sandstone and Helderberg Group, undivided - Oriskany Sandstone: sometimes designated Ridgeley in eastern West Virginia. White to brown coarse- to fine-grained, partly calcareous sandstone, locally pebbly or conglomeratic, and ridge-forming. May be white, nearly pure silica, and a source of glass sand, as at Berkeley Springs, Morgan County. Helderburg 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.

Lithology: sandstone; limestone; shale

Quaternary Alluvium (Quaternary) at surface, covers 0.9 % of this area

Quaternary Alluvium - alluvial deposits of sand, gravel, silt, and clay.

Lithology: alluvium

Pocono Formation (Mississippian) at surface, covers < 0.1 % of this area

Pocono Formation - Sandstone, conglomeratic sandstone, and shale with carbonaceous partings and impure coal beds.

Lithology: sandstone; shale; coal

Maccrady Formation (Mississippian) at surface, covers 1 % of this area

Maccrady Formation - red shale and mudrock, red and green sandstone, and minor limestone. Present only from Pendleton County southward. Contains rock salt and gypsum in southwestern Virginia.

Lithology: shale; sandstone; mudstone; limestone; chemical

Tuscarora Sandstone (Silurian) at surface, covers 0.4 % of this area

Tuscarora Sandstone - medium- to thick-bedded, white to gray or pinkish sandstone, fine to coarse, quartzitic, ridge-forming. Equivalent to the Clinch Sandstone of Tennessee.

Lithology: sandstone

Bluestone and Princeton Formations (Mississippian) at surface, covers 4 % of this area

Bluestone and Princeton Formations (part of Mauch Chunk Group) - the Bluestone Formation is mostly red, green, and medium-gray shale and sandstone; Princeton Sandstone is underneath.

Lithology: shale; sandstone