In the north the plateau is overlain by red and purple unfossiliferous sandstones, capped near its edge by a cherty limestone also unfossiliferous but possibly of Lower Cretaceous age.
On the escarpment around the Blue Grass Region the soils are for the most part either cherty or stiff with clay and of inferior quality.
The main lithic finds include microliths, particularly scalene triangles, and irregularly shaped picks made mostly of cherty limestone.