66 NEW YORK STATE MUSEUM 



can flow. Gilbert, with the knowledge of the glacial theory, sought 

 for a torrent spillway along the retreating ice sheet, and considered 

 '' The Gulf " the outlet for the glacial waters. " The Gulf " there- 

 fore is an integral part of the wonderful story of the great glacial 

 lakes, and the political chance which has drawn the boundary line 

 between Canada and the United States across '^ The Gulf " serves 

 doubly to remind us of its living type, the gorge of Niagara. 



On Thursday, July 4, those who had taken the preliminary trip to 

 Covey hill drove from Mooers southward to West Chazy along many 

 abandoned shore lines, at elevations varying from 300 to 600 feet 

 above the present sea level. At West Chazy others joined the party 

 from Plattsburg, and all met on Cobblestone hill, where a halt was 

 made for an hour to study the remarkable beaches of cobbles show- 

 ing pronounced bars, spits and hooks, at levels of 600 feet and over 

 above sea level. 



These beaches of heavy glacial detritus were laid down in a fresh- 

 water glacial lake, when the ice stood a short distance north of this 

 point, by the waters discharging from the northwest over Flat Rock 

 from the Altona spillway. 



Thence the party drove across the bare Potsdam sandstone over 

 the Altona spillway, where striking evidences were seen of the scour- 

 ing action of torrential glacial waters. After lunch at a spring of 

 water running from the Potsdam sandstone in the spillway the party 

 listened to a talk by Prof. H. L. Fairchild on 



Lake Iroquois extinction 



Lake Iroquois was the great glacial water held in the Ontario 

 basin while the Laurentian ice mass occupied the St Lawrence valley 

 and forced the overflow by the Rome outlet to the Mohawk and 

 Hudson valleys. This original Iroquois outlet was effective for 

 several thousand years, and determined the water level for nearly 

 the whole existence of the glacial waters. 



When the ice body weakened, and the front receded on the salient 

 which projects northeastward from the Adirondacks into Canada, 

 a lower escape for the ice-dammed waters was opened across the 

 Covey hill ridge, precisely at the International boundary. 



" The Gulf," as it is locally known, is a great cut in Potsdam 

 sandstone, long since noted by Emmons and Gilbert, and recently 

 described by Woodworth. The present altitude of the head of the 

 Covey outlet is over 900 feet, but at the time it was opened the 

 locality was about 460 feet lower than today, and the initiation of 



