44 
MUSEUM BULLETIN NO. 25. 
ites are characterized by ripple-mark in a very perfect state of 
preservation according to Daly who states that: “A principal 
feature of the quartzite is the occurrence of extremely well- 
preserved ripple-marks at various horizons. On Mt. Ripple 
itself these markings are exposed in a truly spectacular fashion. 
In bed after bed for a thickness of several hundred feet together 
the surfaces of the old sand were moulded into typical ripples 
of highly varied orientation. As exposed on bedding-planes 
these marks are to-day apparently as sharply marked as they 
were when each bed was just covered by the next wash of sand. 
Whole cliffs are ornamented with the strong ridges and troughs 
of the ripples themselves or with their negative impressions.” 
The Potsdam sandstone of the Cambrian is beautifully 
ripple-marked at many localities. Good examples of ripple-mark 
at this horizon may be seen at South March quarry near Ottawa, 
Ontario, in the quarries near Montebello, Quebec, and at 
Hammond, New York. Photographs of both current and wave 
ripple-marks from the first locality have been published else- 
where. 1 
At South March quarry the rock is a hard, white to buffish- 
grey, moderately coarse sandstone. It is thin-bedded, lying in 
strata 2 to 10 inches thick. Some of the strata are beautifully 
ripple-marked. All of the ripple-marked beds and those associ- 
ated with them appear to be quite barren of fossils, although a 
Lingulepis acuminata Con. occurs abundantly a little lower in the 
section along the railway. Two distinct types of ripple-mark, 
symmetrical and asymmetrical, occur in the highest beds exposed 
on the hilltop. 
Perhaps no formation is more uniformly and generally 
ripple-marked than the Berea sandstone at the base of the 
Carboniferous section of Ohio and northern Kentucky. The 
sandstone has been described by E. B. Andrews 2 * and Orton and 
later by Hyde 8 who studied it with reference to the evidence it 
afforded on the palaeogeography of its epoch. 
1 Kindle, E. M. f Jour. Geol., vol. XXII, pp, 704-705, figure 2. 
* Geol. Surv., Ohio, Rept. Prog. (1869) in 2d. dist., ed. 1870, p. 68; ed. 1871, p. 72. 
* Jour, Geol., vol, 19, 1911, pp. 257-269. 
