1898-99. | THE IROQUOIS BEACH. 29 
THE IROQUOIS: BEACH. 
By Pror. A. P. COLEMAN, PH.D. 
(Read November roth, 1898.) 
THE effect of wave action in cutting cliffs, spreading materials as 
terraces, and heaping up beach sands and gravels is so easily recognised 
that old shore lines, where well marked like those of the Iroquois beach, 
quickly attract attention. Mr. Thos. Roy, a land surveyor in the early 
days of “ Upper Canada,” was the first to refer to the Iroquois beach, in 
a paper on the “ Ancient State of the North American Continent,” read 
by Lyell before the Geological Society of London in 1837. In this 
paper* Roy describes a series of ‘‘ terraces or level ridges” to the north 
of Lake Ontario, the first at 108 feet above the lake, the second at 208 
feet, and a series of higher ones, the last rising 762 feet above Ontario, 
or 996 feet above the sea. It is probable that the beach described as 
two and a half miles north of the lake and 208 feet above it must be 
looked on as the Iroquois beach, though later measurements make its 
height only 170 feet. Roy’s other beaches have not been found with 
certainty by later observers, and it is doubtful if he was correct in his 
inferences, the densely wooded character of much of the country making 
it more difficult in those days to recognise an old beach. 
In 1842 Lyell visited Toronto, largely to examine these terraces, and 
rode in company with Roy about twenty miles north, z.2, to the old 
moraine of the Oak Ridges, and reports having seen in all eleven of these 
apparent beaches, the highest 680 feet above Lake Ontario ; but he is 
not certain that all of them were due to wave action. He says, however, 
that “ with the exception of the parallel roads or shelves in Glen Roy 
and some neighboring glens of the western highlands of Scotland, | 
never saw so remarkable an example of banks, terraces and accumu- 
lations of stratified gravel, sand and clay maintaining over wide areas so 
perfect a horizontality as in the district north of Toronto.” He mentions 
that the second beach, the one at 208 feet, has a shore cliff rising fifty to 
seventy feet, and is covered with boulders ; characters which we find on 
the Iroquois beach near Yonge street, in the northern part of Toronto. 
Roy accounted for this series of supposed beaches by the former 
presence of an immense lake 1,000 feet deep, dammed to the east and 
* Proceedings Geol. Soc., London, Vol. II., No. 51, pp. 537 and 538. 
+ Lyell, Travels in North America, Vel. IIJ., pp. 103-16. 
