A, P. Coleman — Wave Work as a Measure of Time. 351 



Art. XXIX. — Wave Work as a Measure of Time: A Study 

 of the Ontario Basin ; by A. P. Colemak. 



The Pleistocene of the Toronto region has been studied as 

 long and as carefully as that of any part of ^orth America, 

 and the work of waves on lake shores, ancient and modern, and 

 of rivers entering the successive lakes in the Ontario basin has 

 been of great importance in determining the geological rela- 

 tionships. Its study may be said to have begun with the visit 

 of Sir Charles Lyell to the raised beaches (Iroquois) north of 

 the town in 184:2 ;'^ and to have been continued by the distin- 

 guished engineer, Sir Sandford Fleming, who in 1850 described 

 the growth of Toronto island by the transport of materials from 

 Scarboro' Heights,t and in 1861 gave an excellent account of 

 a part of the Iroquois beach to the north of Toronto.ij: In 

 1880 Dr. Spencer and Dr. Gilbert showed that the beaches of 

 the ancient lake were deformed, and the appropriate name of 

 the Iroquois Water was given to the predecessor of Lake Ontario 

 by Dr. Spencer.§ Since then various papers have been pub- 

 lished by the present writer on matters connected with Lake 

 Iroquois and other lakes and rivers which formerly played a 

 part in the history of the region, the latest in 1913. || In this 

 paper an attempt was made to work out the age of Lake Ontario 

 from the rate of recession of the Scarboro' cliffs and the 

 distance they had receded, additional, though less reliable, evi- 

 dence being deduced from the growth of Toronto island. 

 The results thus obtained have recently been criticised by Dr. 

 Spencer in an article on the "Origin and Age of the Ontario 

 Shore Line."*|f Dr. Spencer's pioneer work on Lake Iroquois 

 was so good that his views on the history of the Ontario basin 

 will naturally receive careful consideration. The question of 

 the age of Lake Ontario is of so much interest that a further 

 discussion of the matter is desirable, since the difference between 

 8,000 years, as determined by myself, and 2,000, as worked out 

 by Dr. Spencer, is far too great to be accidental. In reading 

 his paper carefully it appears that through lack of personal 

 knowledge of the region he has made some incorrect assump- 

 tions which lead to wrong conclusions, and it is proposed to 

 restate the problem and show how the errors occurred. 



* Travels in North America, vol. ii, pp. 103-8. 



t Jour. Can. Inst., 1854, pp. 107-223. 



ilbid., 2d Series, vol. vi. pp. 247-253. 



§The Iroquois Beach, Trans. Roy. Soc. Can., 1889, p. 121, etc. ; and 

 other publications. 



II An Estimate of Post-glacial and Interglacial Time in North America, 

 Congres Geologique, Xlle Session, Compte-Eendu, pp. 435, etc. 



IT This Journal, vol. xliii. No. 257, pp. 351-362, May, 1917. 



