The Belpre bentonite of Collins (1979) is here named the Belpre Ash Bed and accepted for USGS usage. In the Appalachian basin the bed is near the base of the black shale beds of the Olentangy Shale in the subsurface of eastern OH and eastern KY; in the Rhinestreet Shale Member of the West Falls Formation in northwestern PA, western WV, southwestern VA, and northeastern TN, all in the subsurface; and at the surface in southwestern VA and northeastern TN in that part of the Chattanooga Shale that is equivalent to the Rhinestreet Shale Member in the subsurface. The Belpre is composed of Md illite, kaolinite, illite-smectite mixed layer clay, quartz, and biotite. Volcanic ash beds of Devonian age in the Appalachian basin are mineralogically and physically unlike bentonite as defined originally and by industry, which requires that smectite be the principal constituent. Thickness ranges from 0.5 to 30 cm. Age is Late Devonian.

Source: GNU records (USGS DDS-6; Reston GNULEX).

Cross section between Norton and Asberrys, VA, in the Clinch Mountain outcrop belt shows more detailed divisions of Chattanooga Shale than previously indicated. Base of Chattanooga is marked by Belpre Ash, which occurs within the Rhinestreet Shale Member, and Center Hill Ash occurs within the Java Shale Member.

Source: GNU records (USGS DDS-6; Reston GNULEX).