Geologic units in Monongalia county, West Virginia

Dunkard Group (Permian/Pennsylvanian) at surface, covers 41 % of this area

Non-marine cyclic sequences of sandstone, siltstone, red and gray shale, limestone, and coal. Contains the Greene, Washington and Waynesburg Formations. Extends from the top of the exposed bed rock section to the top of the Waynesburg coal. Includes the Washington coals and limestones. Palynological evidence favors a Pennsylvanian age, at least for the lower portion.

Conemaugh Group (Pennsylvanian) at surface, covers 25 % of this area

Cyclic sequences of red and gray shale, siltstone, and sandstone, with thin limestones and coals. Mostly non-marine. May be divided into Casselman and Glenshaw Formations. Extends from the base of the Pittsburgh coal to the top of the Upper Freeport coal. Includes the Elk Lick, Bakerstown, and Mahoning coals, and the Ames and Brush Creek Limestones.

Monongahela Group (Pennsylvanian) at surface, covers 11 % of this area

Non-marine cyclic sequences of sandstone, siltstone, red and gray shale, limestone, and coal. Contains the Uniontown and Pittsburgh Formations. Extends from the top of the Waynesburg coal to the base of the Pittsburgh coal. Includes the Waynesburg, Uniontown, Sewickley, Redstone and Pittsburgh coals. Thickness is 170 feet in Mineral and Grant Counties.

Allegheny Formation (Pennsylvanian) at surface, covers 9 % of this area

Cyclic sequences of sandstone, siltstone, shale, limestone, and coal. Includes the Freeport, Kittanning and Clarion coals, also, the Princess coals of Kentucky . Extends from the top of the Upper Freeport coal to the top of the Homewood Sandstone.

Pottsville Group (Pennsylvanian) at surface, covers 8 % of this area

Includes the Kanawha, New River, and Pocahontas Formations. Predominantly sandstones, some of which are conglomeratic, with thin shales and coals. Undivided in northern West Virginia.

Quaternary Alluvium (Quaternary) at surface, covers 3 % of this area

Alluvial deposits of sand, gravel, silt, and clay.

Mauch Chunk Group (Mississippian) at surface, covers 2 % of this area

Red, green, and medium-gray shale and sandstone, with a few thin limestones.

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.

Pocono Group (Mississippian) at surface, covers 0.3 % of this area

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

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

Cyclic sequences of shale, siltstone, sandstone, red beds, thin, impure limestone, and thin, nonpersistent coal; red beds are associated with landslides; base is at top of Ames limestone.

Monongahela Group (Pennsylvanian) at surface, covers 0.1 % of this area

Cyclic sequences of limestone, shale, sandstone, and coal; commercial coals present; base is at bottom of Pittsburgh coal.

Washington Formation (Permian) at surface, covers < 0.1 % of this area

Cyclic sequences of sandstone, shale, limestone, and coal; includes some red shale; base is at bottom of Washington coal.

Greene Formation (Permian) at surface, covers < 0.1 % of this area

Cyclic sequences of sandstone, shale, red beds, thin limestone, and thin, impure coal; base is at top of Upper Washington limestone.

Waynesburg Formation (Permian and Pennsylvanian) at surface, covers < 0.1 % of this area

Cyclic sequences of sandstone, shale, limestone, and coal; commercial coals present; base is at bottom of Waynesburg coal.

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

Cyclic sequences of sandstone, shale, limestone, clay, and coal; includes valuable clay deposits and Vanport Limestone; commercially valuable Freeport, Kittanning, and Brookville-Clarion coals present; base is at bottom of Brookville-Clarion coal.

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

Cyclic sequences of shale, sandstone, red beds, and thin limestone and coal; includes four marine limestone or shale horizons; red beds are involved in landslides; base is at top of Upper Freeport coal.

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

Predominantly gray sandstone and conglomerate; also contains thin beds of shale, claystone, limestone, and coal; includes Olean and Sharon conglomerates of northwestern Pennsylvania; thin marine limestones present in Beaver, Lawrence, and Mercer Counties; minable coals and commercially valuable high-alumina clays present locally.

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

Grayish-red shale, siltstone, sandstone, and some conglomerate; some local nonred zones. Includes Loyalhanna Member (crossbedded, sandy limestone) at base in south-central and southwestern Pennsylvania; also includes Greenbrier Limestone Member, and Wymps Gap and Deer Valley Limestones, which are tongues of the Greenbrier. Along Allegheny Front from Blair County to Sullivan County, Loyalhanna Member is greenish-gray, calcareous, crossbedded sandstone.