Marine sandstones, siltstones, and shales, typically brown to gray in color. There is a generally coarsening-upward sequence with shales dominant near the base and sandstones dominant near the top. Marine siltstones and shales, thin bedded and typically dark brown to gray in color. The contact with the overlying Chemung is gradational and usually drawn where several beds of sandstone greater than two feet thick are present. The contact with the underlying Millboro is also gradational and is drawn where the laminated black shales of the Millboro give way to the thin-bedded shales and siltstones of the Brallier.
Fossils are rare.
Sometimes the color of weathered shale can be brown or red, depending on its iron content. Saprolitic shales can be nearly white. Rare beds of micritic limestone up to a few feet in thickness can be found in the field camp mapping areas. Fossils are very rare, consisting of pelagic organisms and brachiopods. Mostly a highly silicified black shale containing beds that are brecciated and recemented with amorphous silica.