It consists of alternating beds of ferruginous oolitic chert and fine-textured cherty carbonates. The Flint Hills developed on the north-south exposure of Permian cherty limestones. Sedimentary-derived soils may be stone free, not cherty as in neighboring regions. Cerrati, Cerati, Cerrati, Cerruti, Cherty, Cherti, Ceruti, and many others.. Hard formations include hard shale, calcites, mudstones, cherty lime stones and hard and abrasive formations. Pine is most common on steep, thin, cherty soils. Typical lithologies include thick-bedded cherty dolomites and limestones.