7i 

 IROQUOIS BEACH. 



BY 



A. P. Coleman. 



GEOLOGY AND PHYSIOGRAPHY OF THE 

 HAMILTON DISTRICT. 



As shown in former pages by Mr. Taylor, the most 

 striking physiographic feature of the Ontario region is the 

 Niagara escarpment, which runs as cliffs facing northward 

 from Queenston to Hamilton, then turns northeast to 

 Waterdown, and finally bends to the northwest to the shore 

 of Georgian bay. The cliff is due to the more rapid 

 attack of the weather upon the soft underlying shales 

 than upon the protecting layer of resistant limestone 

 on top. It ranges in height from 300 to 400 feet (90 to 

 120 m.) above the plain which slopes gently down between 

 its foot and Lake Ontario. 



A short distance inland on each side of the lake there 

 is a less conspicuous feature, to which reference has also 

 been made — the old shore of Lake Iroquois, which 

 occupied the basin toward the close of the Ice Age when the 

 removal of the ice sheet had progressed as far as the 

 Thousand Islands region, though the St. Lawrence valley 

 beyond was still blocked. 



The old shore of Lake Iroquois has been mapped 

 by Gilbert and Fairchild in New York, and by Spencer 

 and Coleman in Ontario; and it was early recognized by 

 Dr. Spencer that the beach was no longer horizontal, 

 but had been deformed by the upward warping of the 

 earth's crust toward the northeast. It is commonly very 

 well defined, with cliffs and gravel bars as mature as 

 those of the present lake. At Lewiston and Queenston, 

 as mentioned before, its level is about 125 feet (38 m.) 

 above Ontario, but at Hamilton its height is 116 feet 

 (35-4 m.) and at Toronto 176 feet, (53-6 m.) toward 

 the west and 200 feet (61 -o m.) toward the east. Between 

 Hamilton and Toronto its deformation is at the rate 

 of 2 feet per mile (-38 m. per km.). To the east of Toronto 

 it increases to 3-4 feet and at the far northeastern end 

 reaches 5 or even 7 feet per mile, its last observed point 

 rising 495 feet (150-8 m.) above Lake Ontario. The 



