84 NEW YORK STATE MUSEUM 



giving birth to the South Meadows Lake. The uncovering of lower 

 outlets to the west extinguished this lake which was succeeded by 

 Upper Lake Newman. During this stage the ice lobe that lay in the 

 East branch of the Ausable, eastern section, retreated to allow the 

 Keene lake to form, with its drainage to the south. A further lower- 

 ing of the waters caused a separation of the Boreas-Elk-Clear pond 

 region from the major portion of the Keene lake, which continued to 

 exist as a separate unit. A further subdivision brought about several 

 smaller glacial lakes in the Schroon Lake quadrangle. The contin- 

 ued withdrawal of the ice lobe uncovered the Wilmington notch and 

 thus the Keene lake fell to the level of Upper Newman ; bringing 

 about a union of the two sections. Succeeding Upper Newman, 

 Lower Newman held the stage until the withdrawal of the lobe in the 

 Elizabethtown-Pleasant valley opened the side outlet channels in the 

 center of the Ausable sheet, when the Saranac glacial waters held 

 dominion, draining east. During the lower stages the western sec- 

 tion was drained and only the eastern section was flooded. 



The Wilmington lake, drained through the Gulf ; and the Upper 

 Jay lake, both Upper and Lower phases, likewise drained to the east. 

 The lakes that succeeded the Upper Jay lakes did not cover any 

 portion of the Mount Marcy quadrangle and are not described in 

 detail. 



The nature of the postlacustrine uptilting, which inclined the shore 

 lines of the lakes northward, points to the conclusion that the land 

 was experiencing uplift and warping while the ice was retreating 

 from the region. The total amount of uplift since glacial times for 

 the quadrangle may have been greater than 600 feet. 



