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NEW YORK STATE MUSEUM 



benches in lateral valleys owe their present courses to glacial em- 

 barrassments. The Ausable has an old valley near Keeseville west 

 of its present course, and the drift filling must be very deep at and 

 above Keeseville. 



The deep notches of the Winooski and the Lamoille rivers 

 through the Green mountains, draining lowland basins on the east 

 of this range, correspond in topographic development with the 

 high level valley floors worked out in the Adirondacks, but this 

 stage is apparently older than that of the immediate vicinity of 

 the Hudson and Champlain valley floors. 



GLACIAL MOVEMENT THROUGH THE HUDSON AND CHAMPLAIN VALLEYS 



The observed striae throughout the Hudson and Champlain val- 

 leys, accord closely with the direction of the axis of this great de- 

 pression and with the expansion and contraction of the valley 

 walls. Throughout the entire district the direction of transpor- 

 tation of debris, the arrangement of the glacial deposits, the form 

 of roches moutonnees and every feature indicative of glacial 

 erosion points conclusively to the general southward movement of 

 ice from the broad open northern expanse of the Champlain valley 

 southward. 



Along the Xew York shore of Lake Champlain there is marked 

 tendency of the striae to turn southwestward, indicating a move- 

 ment of the ice upward over the basal slopes of the Adirondacks as 

 the ice became pressed within the narrowing southern part of the 

 Champlain valley. At Port Henry this tendency Is so marked 

 that it may be doubted whether further detailed examination of 

 the region back from the lake may not show the existence of local 

 glaciers moving down the slope so as to produce the eastwest stri- 

 ation seen just south of the town [see p.156] . 



Through the southern arm of Lake Champlain the ice moved 

 southwestwardly through the defiles of the mountains and out on 

 the plain about Fort Edward. This southwestward movement 

 is well shown at Glens Falls where striae have a course 

 n. (33° e. Thence the movement Avas southward through 

 the Hudson valley. About Albany the ice appears to have 

 backed up in its advance against the Helderberg escarpment on 

 the south and west. It has long been known that, in this latitude, 



