Juniata Formation. Refer to description under Ous. Oswego Formation (Prosser, 1890). Sandstone, greenish gray, fine- to coarse-grained, conglomeratic with chert, quartz, and lithic pebbles. Minor interbeds of olive-gray shale with thin sandstone layers. Conformable with underlying Reedsville Shale. Present northeast of Bath and Augusta counties but thins in all directions from a maximum thickness of 500 feet in western Rockingham County (Diecchio, 1985). Reedsville Shale. Refer to description under Ou. Dolly Ridge Formation (Perry, 1972). Limestone, medium-gray, fine-grained, thin-bedded, argillaceous, with interbedded olive-gray, calcareous claystone, silty argillaceous limestone, gray shale and thin K-bentonite beds. Thickness about 400 feet in Bath and Highland counties; laterally equivalent to the Trenton Limestone and part of the lower Martinsburg Formation of previous reports in western Virginia. It is gradational with the underlying Eggleston Formation. Eggleston Formation. Refer to description under Ou. Martinsburg Formation. Refer to Om (Martinsburg and Oranda Formations) for description. The Martinsburg is only present with this map unit (Oun) in northern Rockingham County where it occupies the Reedsville Shale - Dolly Ridge Formation interval.