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. 22. Facies E. Sandstone with ripple cross-stratification and cross-lamination dipping in opposite directions (Gaskill).