Geological Survey research 1968: Chapter C

Refractory flint clay and semiflint clay layers, totaling as much as 7% feet in thickness, occur in the lower part of the Allegheny Formation of Pennsylvanian age in north-central Randolph County, W.Va. The deposit seems to be a lens in a widespread bed of plastic clay and may underlie an area of 1-2 square miles. Refractory tests of three samples indicate a pyrometric cone equivalent of cone 30-31 which is comparable with tests of the most highly refractory clay previously reported from West Virginia.