46 NEW YORK STATE MUSEUM 



The general direction of movement of the ice of the last epoch 

 of invasion was, in the region under consideration, about 42 ° west 

 of south. A control of the direction of movement was evidently 

 effected by regional topography. 



When at length the final melting of the ice took place, the two 

 highlands regions were first uncovered, a thick lobe of ice lingering 

 in the central basin. Probably at the same time another lobe of ice 

 occupied the great valley of the Hudson. Presumably close upon 

 the melting of the latter the valley became filled with, waters, form- 

 ing Lake Albany. Eventually the Lake Albany waters covered all 

 parts of the area, the present elevation of which is 400 feet or less 

 above sea level. 



The ice lobe occupying the central basin was slowly melted back 

 at its front, leaving in its wake the thick deposits already gathered 

 under the glacier and which to a large extent had been left molded 

 into elliptical hills, or drumlins. At its western margin the ice lobe 

 suffered comparatively rapid melting, due to the heat reflected from 

 the bared, rocky slope of the highlands. The depression thus formed 

 between the ice and the slope became a channel for flowing waters 

 derived from the melting ice to the north. This stream, at times 

 large in volume and of strong currents, laden with sand and gravel, 

 in places dropped its load and, following the lateral margin of the 

 shrinking ice lobe, gradually built up groups of moundlike hills, or 

 kames, and flat-topped stretches of sand and gravel, or kame ter- 

 races. 



When the central lobe had melted back as far as 3 miles south of 

 Corinth, a balanced condition between recession by melting and 

 advance by the flowage of the ice supervened. Along the stationary 

 or slightly shifting ice front the debris brought by the glacier 

 accumulated, forming a moraine extending all the way across the 

 basin. The waters issuing from the ice front carried the finer 

 materials borne by them beyond the edge of the ice, building outwash 

 plains. The largest of these formed in front of the western end of 

 the morainic belt, extending southward in the line of the preglacial 

 drainage valley. 



When the ice front renewed its retreat to the north, waters from 

 the melting ice became ponded back of the moraine, originating 

 Lake Corinth. Also a second lake, farther to the east and beyond 

 a ridge, developed behind the eastern end of the morainic belt where 

 it abutted against the foot of the Luzerine mountain. These lakes 

 received deposits of sand and gravel, now represented by the sand 



