Kansas Geological Survey, Current Research in Earth Sciences, Bulletin 243, part 1
Sedimentology and Ichnology of Paleozoic Estuarine and Shoreface Reservoirs, Morrow Sandstone, Lower Pennsylvanian of Southwest Kansas, USA

Fig. 15. Facies D. Parallel-laminated shales with thin, very fine grained sandstone lenses forming connected starved ripples.