Geologic units in Summers county, West Virginia

Hinton Formation (Mississippian) at surface, covers 55 % of this area

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

Bluestone and Princeton Formations (Mississippian) at surface, covers 22 % of this area

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

Bluefield Formation (Mississippian) at surface, covers 18 % of this area

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

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

(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.

Greenbrier Group (Mississippian) at surface, covers 0.6 % of this area

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

New River Formation (Pennsylvanian) at surface, covers 0.5 % of this area

(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.