The Keefer Sandstone in the subsurface of West Virginia and Kentucky, where it produces small volumes of natural gas, was deposited on the western shelf of the Appalachian basin. The formation is a dolomitic quartzarenite and quartzwacke and ranges from 13 to 50 ft (4 to 15 m) thick. As interpreted from four cores and isopach and lithofacies maps, the sand was transported by longshore currents from a southeastern source area and laid down in a variety of environments. In Kentucky, Keefer deposition was on a wave-dominated coast. The rocks are characterized by physical sedimentary structures and textures which developed under high-energy conditions, and the formation is divided into shoreface and foreshore facies. In adjacent West Virginia, however, Keefer deposition occur ed offshore in water near the depth of wave base, swept out onto the shelf by storm-generated currents. Sedimentary structures and textures indicate a lower energy environment, bioturbation is more common, and the formation contains a greater amount of shale. The isopach map shows two linear tracts of thick sand in this offshore facies that may represent a coalescence of subtidal bars on the shelf. Between major sand bodies, the Keefer becomes appreciably thinner and is interbedded with fossiliferous dolomite. In the basin center of West Virginia, sandstone is replaced by shale. Thus, the geographical distribution of lithofacies shows a transition of shelf environments within a blanket sandstone. In all cores, regardless of depositional facies, the sandstone displays evidence of aggradin sedimentation; sedimentation exceeded subsidence, and the sand body built upward into shallower water.

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