Carbonate-rich Shale, Siliceous Shale and Cannel Shale
Nepheline-Basanite, Analcite-Basanite and Leucite-Basanite
Easily splits into thin plates, Generally rough to touch, Is one of the oldest rock, Very fine grained rock
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate, Used as a touchstone