GLACIAL LAKES AND CHANNELS NEAR SYRACUSE 761 



channel, of which nothing was known, the river could not have found a 

 passage north. 



GLACIAL LAKES AND CHANNELS NEAR SYRACUSE- 

 BY T. C. HOPKINS 



(Al)stract) 



Where the south-moving glacier met the north slope of the Allegheny pla- 

 teau with its northward drainage there would be considerable ponding of the 

 waters that could be released only by an east or west outlet. During this 

 east-west drainage across the divides between the north-flowing streams 

 numerous high channels would be formed. Where these glacial streams drop 

 over a cliff, a basin or pool would be eroded that after the disappearance of 

 the glacial stream would remain as a pond or lake. The writer has evidence 

 to indicate that a number of these so-called glacial lakes were not formed in 

 this way, but are due in large measure to solution by the ground waters. 



ISOBASES OF THE ALGONQUIN AND IROQUOIS BEACHES AND THEIR 



SIGNIFICANCE 



BY J. W. GOLDTHWAIT 



Published as pages 227-248 of this volume. 



Discussion 



Dr. J. W. Spencer said that he was much interested in the work of Pro- 

 fessor Goldthwait, who had extended the surveys of the Algonquin beach to 

 the west about Lake Michigan. Doctor Spencer also stated that all his own 

 leveling of the Algonquin some twenty years ago, as also that of the Iroquois 

 beach on the north side of Lake Ontario, had been made by use of the "Y"- 

 level. He also said that he had shown that the upward warping of the Huron 

 and Ontario regions pointed to an ellipse north of the city of Ottawa rather 

 than to a center of glaciation. This was some three years before De Geer 

 visited the region. Doctor Spencer said that he was particularly gratified that 

 the newer details brought out by Professor Goldthwait fully confirmed the 

 original conclusions. 



Mr. F. B. Taylor: The gravelly delta at Peterboro, Ontario, is apparently 

 in a slightly constricted bay connecting with Lake Iroquois, as has been stated 

 by Coleman, and may be very slightly higher than the Iroquois beach on that 

 account. But it is also in the belt bordering on the Archean area, where the 

 old water plane as found at Kirkfield and Orillia takes on a relatively sudden 

 increase in the rate of its northeastward rise. Thus it may after all stand at 

 or very nearly at the Iroquois level, although it seems at first too high. 



Professor Goldthwait replied as follows: These methods have been pre- 

 sented in earlier papers. The crest of a beach ridge or the foot of a sharply 

 cut bluff, where most typically developed, have been selected for measure- 

 ment. Usually the modern lake has been used as a starting point from which 

 to run the levels. The original variations in height of the beach and the pos- 

 sible error in the leveling together are probably not over 7 or 8 feet. In spite 



• Read by title, In the absence of the author. 



