82 



NEW YORK STATE MUSEUM 



pass and the Chapel pond pass on the western edge of the EHza- 

 bethtO'wn sheet, although much lower than the surface of the water, 

 were effectively blocked by side ice lobes from the glacial tongue 

 that occupied the Elizabethtown valley, preventing eastward escape. 

 It seems quite likely that as the lobe, which prevented northward 

 escape of the Keene lake, gradually retreated, it at last uncovered 

 the eastern end of the Wilmington notch which furnished connec- 

 tion with the western portion of the area, and then the waters in 

 the valley of the East branch fell to the level of Upper Lake 

 Newman. 



WISCONSIN ICE 



GLKCIHL LBKE 

 LOWER NEWMRN 



5 EXISTING LBKE5 

 TOWNS 



SRRRNRq 



LHKE 

 PLRCID 



\ 



SRNRNTON\ 



MT 

 MRRCY 



\ 



M \A M 



SCRLE OF MIUES 



^^,^■^s^^^^'^%: 



Fig. 4 The Glacial Lake succession in the Lake Placid quadrangle. 

 Stage three. 



The Keene lake was succeeded by the eastern section of Upper Lake 

 Newman when the ice lobe in the valley of the Ausable river had retreated 

 to uncover the Wilmington notch, allowing discharge to the west. Both 

 eastern and western sections of Upper Lake Newman were succeeded by 

 Lower Lake Newman, altitude 1740 to 17180 feet. 



