GEOLOGY OF MOUNT MARCY 



79 



Remnants are situated on the east side of the valley composed of 

 very fine sand while the western exposures are made up of coarser 

 materials. At the valley wall distributary channels are well shown ; 

 pebbles and boulders as large as one's fist or larger are common. It 

 is evident that the delta materials came from the Johns Brook valley 

 and were deposited in standing waters by the ice-fed Johns " river." 



Fig. 14 The glacial lake succession in the Mount Marcy and adjacent 

 quadrangles. Stage 6. The Upper Jay lake (upper phase), altitude, 1017 to 

 1046 feet. 



A number of beaches of the lake are beautifully shown on a hill a 

 mile north of Keene, in the Lake Placid sheet. The altitude of the 

 best developed one is 11 13 feet. Farther to the northeast we find 

 the spillway at the entrance of the gulf in the Ausable sheet at 11 57 

 feet. The cause of these apparently nonconcordant figures is due to 



