and Birth of Lake Huron. 13 



topography of the country. I have named it after the In- 

 dians who, long ago, used it for a trail — the Algonquin Beach. * 

 It forms the basis of this paper. 



Between Lakes Huron, Ontario and Erie, at respective alti- 

 tudes of 582, 573, and 247 feet above the sea, the land rises to 

 1709 feet. It shows water action to within 20 feet of its sum- 

 mit. From the highest ridges or plains, the land falls away 

 towards the lakes, sometimes gradually, but often by abrupt 

 steps, especially upon the northeastern side. Over this 

 peninsula, there are many ridges of drift. Exclusive of the 

 ridges, the general surface of the country is composed of fine 

 stony till, or of modified drift, — the product of wave action 

 upon the stony clay, the result of which has been the forma- 

 tion of beach ridges of sand and gravel, separated by plains of 

 silt or clay soil. In many cases, these floors slope so gently as 

 to appear level, and from two to five or six miles may inter- 

 vene between successive beaches, whose altitudes do not differ 

 by more than 50 or 60 feet. The silt on these plains is that 

 which was washed out into the deeper water, by the assorting 

 action of the waves that were building sand or gravel beaches 

 in front of their coast lines, composed of the older stony 

 clay. In such cases, the lithological recognition is striking. 

 Upon surveying, the beaches are all found to rise in altitude 

 toward the north and east, with a slightly increasing diverg- 

 ence between the ridges in the same direction, for the differ- 

 ential uplift has always been greater toward the northeast, 

 than in the opposite direction. 



The methods of investigation have been similar to those 

 pursued in the survey of the Iroquois Beach. Boulder pave- 

 ments are rather more important features of the Algonquin 

 Beach than of the Iroquois. About the head of Georgian 

 Bay the country is sandy. East of Georgian Bay, there is 

 the same kind of broken wilderness as that among the Archssan 

 rocks of the Adirondack Mountains of New York, with more 

 or less stony sand in place of stony clay. 



The waves of the lake are encroaching upon the eastern 

 coast of Huron, and consequently modern beach-making is 

 not a characteristic feature, except in proximity to the mouths 

 of some streams or in sheltered places, where terraces or bars 

 are constructed. The encroachments of the lake upon the land 

 have washed away, in many places, the bluffs upon which the 

 Algonquin Beach rests. But a sufficient number of fragments 

 remain, for its identification, especially as the position relative 

 to its elevation, compared with the next higher shore-lines, 

 which are well marked by beaches, is known. 



* The name was first printed in Proc. A. A. A. S., p. 199, 1888. 



