A local development of ripple marks can be seen on the upper surface of the basal three-foot limestone bed of the Sandbanks Limestone on the coast south of Spittal, Northumberland, northern England. The ripple marks occur for only about 150 feet and are exposed only at low tide. They are very large and for the most part are symmetrical. It is presumed that the ripples formed by oscillatory wave motion after the calcareousmud was partially consolidated, and that they have been preserved only because their formation was immediately followed by a quiet period of shale deposition. The occurrence is unique in Carboniferous rocks in Great Britain, as far as is known.