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

Geologic units in Clay county, West Virginia

Allegheny Formation (Pennsylvanian) at surface, covers 48 % of this area

Allegheny Formation - 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.

Lithology: sandstone; siltstone; shale; limestone; coal

Kanawha Formation (Pennsylvanian) at surface, covers 19 % 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

Conemaugh Group (Pennsylvanian) at surface, covers 30 % of this area

Conemaugh Group - 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.

Lithology: shale; siltstone; sandstone; limestone; coal

Monongahela Group (Pennsylvanian) at surface, covers 3 % of this area

Monongahela Group - 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.

Lithology: sandstone; siltstone; shale; limestone; coal