SUPERFICIAL GEOLOGY OF DUNDAS VALLEY. 141 



any outlet for the waters of Lake Ontario towards the north-east by 

 the St. Lawrence in pre-glacial times. 



The fiuviatile theory is supposed by Mr. J. F. Carll, of the 

 Geological Survey of Pennsylvania, and Professor Spencer, of King's 

 College Windsor, N. S. Mr. Carll has shown by numerous measure- 

 ments of borings that the whole, or at least the greater part of the 

 pre-glacial drainage of the northern division of the State of Pennsyl- 

 vania, was into Lake Erie, and from the directions in which these 

 streams entered Lake Erie that their course must have been down 

 the lake towards the northeast. 



Prof. Claypole, in a paper on the origin of Lake Erie, also sup- 

 ports Mr. Carll, by stating that the basin ot Lake Erie must have 

 existed before the advent of the glacial period. He says " If Lake 

 Erie had been excavated in this manner (that is, by glacial action) 

 there would have been evidence of the beds of drift around the south 

 end of the lake " He ascribes the formation of Lake Erie to the 

 action of an ancient river flowing through the region in pre-glacial 

 times. Lakes Erie and Ontario would then be broad, open valleys 

 worn out where the rocks were soft, and connected by deep channel, 

 where they were hard. 



Professor Spencer, in his paper, assumes this theory as correct 

 and points out that the deep channel connecting the two lakes, Erie 

 and Ontario, would in all probability be through Dundas valley. 



The evidence gathered by personal inspection and given in the 

 foregoing pages, all tend towards the confirmation of the theory laid 

 down by Professor Spencer, that Dundas valley formed in preglacial 

 times the connecting link between Lake Erie and Lake Ontario. 



One objection to this theory might, however, be raised. There 

 does not appear to be any outlet for the water of this river after reach- 

 ing Lake Ontario. Professor Spencer has, after examining the dis- 

 trict to the south of the lake been unable to find a position for an 

 outlet. I am unacquainted with this region, but from a study of the 

 maps of the United States Coast survey, and the frequency of rock 

 bottom, would favor the opinion that some local elevation has had 

 the effect of closing up the old channel, and by damming up the 

 waters has formed Lake Ontario and forced the water to find a new 

 channel through the St. Lawrence. Of this, however, I have no 



