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

Geologic units in Craig county, Virginia

[Additional scientific data in this geographic area]

St. Paul Group (Ordovician) at surface, covers < 0.1 % of this area

St. Paul Group - includes the New Market and Row Park Limestones. Predominantly medium-gray aphanitic limestone, containing very low-silica, cream-colored member of considerable economic importance. Chert nodules and dolomite occur in the Row Park.

Lithology: limestone; chert; dolostone (dolomite)

Knox Group (Cambrian-Ordovician) at surface, covers 8 % of this area

Knox Group - dolostone, limestone, sandstone. Includes the Mascot Dolomite, Kingsport Dolomite, Chepultepec Dolomite, Copper Ridge Dolomite. (Includes: Ob, Omk, Occo, Cco, Occc.)

Lithology: dolostone (dolomite); limestone; chert; sandstone

Tuscarora Sandstone (Silurian) at surface, covers 0.1 % 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

McKenzie Formation, Clinton Group and Tuscarora Sandstone, undivided (Silurian) at surface, covers 0.2 % of this area

McKenzie Formation, Clinton Group and Tuscarora Sandstone, undivided - 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. 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: shale; sandstone; limestone

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

Lower Ordovician and Upper Cambrian Formations Undivided (Cambrian-Ordovician) at surface, covers < 0.1 % of this area

Lower Ordovician and Upper Cambrian Formations Undivided - Includes Pinesburg Station Dolomite, Rockdale Run Formation, Beekmantown Formation, Stonehenge Limestone and Conococheague Formation.

Lithology: limestone; dolostone (dolomite); chert; sandstone

Juniata, Reedsville, Trenton, and Eggleston Formations (Ordovician) at surface, covers 7 % of this area

Juniata, Reedsville, Trenton, and Eggleston Formations - Dusky-red shale and mudstone and sandstone; shale and limestone. Note: one area in southeastern Bland County has landslides with intact stratigraphic units.

Lithology: shale; mudstone; sandstone; limestone

Nolichucky and Honaker Formations (Cambrian) at surface, covers 0.5 % of this area

Nolichucky and Honaker Formations - Dolomitic shale; dolomite and minor chert.

Lithology: shale; dolostone (dolomite); chert

Chemung Formation (redefined as Foreknobs Formation) (Devonian) at surface, covers 2 % of this area

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

Lithology: shale; sandstone; conglomerate

Ridgeley Sandstone, Helderberg and Cayugan Groups (Silurian-Devonian) at surface, covers 9 % of this area

Ridgeley Sandstone, Helderberg and Cayugan Groups - Calcareous sandstone; partly cherty limestone; calcareous shale; fossiliferous.

Lithology: limestone; sandstone; shale

Millboro Shale and Needmore Formation (Devonian) at surface, covers 23 % of this area

Millboro Shale and Needmore Formation - Black, fissile shale; gray calcareous shale; Tioga metabentonite at top of Needmore.

Lithology: black shale; shale; bentonite; limestone

Lower Devonian and Silurian Formations Undivided (Silurian-Devonian) at surface, covers 11 % of this area

Lower Devonian and Silurian Formations Undivided - Some landslides with intact stratigraphic units in Craig County area. Includes: Dsu, Skrt, Sm. (Shrc?)

Lithology: sandstone; limestone; shale

Keefer, Rose Hill, and Tuscarora Formations (Silurian) at surface, covers 12 % of this area

Keefer, Rose Hill, and Tuscarora Formations - Quartzarenite, dusky-red shale, and sandstone, Some landslides with intact stratigraphic units in Craig County area..

Lithology: arenite; shale; sandstone

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

Moccasin or Bays Formation through Blackford Formation (Ordovician) at surface, covers 4 % of this area

Moccasin or Bays Formation through Blackford Formation - Dusky-red shale and mudstone; sandstone; limestone, in part cherty; and calcareous shale.

Lithology: shale; mudstone; sandstone; limestone; chert

Harrell Shale (Devonian) at surface, covers < 0.1 % of this area

Harrell Shale (part of Millboro Shale) - dark gray to black thinly laminated to fissile shale. Calcareous shale and limestone lenses near the base (Tully).

Lithology: shale; limestone

Brallier Formation (Devonian) at surface, covers 23 % of this area

Brallier Formation - Micaceous shale, siltstone, and sandstone.

Lithology: shale; siltstone; sandstone

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

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

Lithology: sandstone; shale; siltstone; limestone; conglomerate; coal

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

Mahantango Formation (part of Millboro Shale) - thickly laminated marine shale, siltstone, very fine sandstone, and some limestone, with an occasional coral reef or biostrome. Contains the Clearville and Chaneysville Siltstone Members of Pennsylvania.

Lithology: shale; sandstone; siltstone; limestone; coral