ELIZABETHTOWN GROUP 665 



It gives one the impression that it was a delta formed in standing- 

 water by inflowing streams. Two stream valleys to the north, Falls and 

 Jackson brooks, are drift-laden and promise to reveal terraces of some 

 higher lake levels when investigated. 



North Hudson Lake (altitude, 1,150 feet). — In the valley of the 

 Schroon Eiver and New Pond Brook a badly eroded terrace plain is situ- 

 ated at 1,150 feet. In the vicinity of Euba Mills and Underwood the 

 terraces are rather prominent. Areas about Lincoln Pond and 2 miles 

 east of Elizabethtown appear to be plains of the same level. 



Lake Poitersville (altitude, 900 to 980 feet; Holiday Lake, altitude, 980 

 feet). — "Along the Schroon Eiver, just west of Holiday Pond, there is 

 an extensive gravel terrace with pebbles up to 2 inches, and with its top 

 at the 980-foot contour. There must have been ponding of water at this 

 locality. . . . The character is such as to argue delta conditions, 

 rather than a lake bottom. Still farther south a terrace is again pro- 

 nounced between 940 and 960 feet, where the highway crosses and leaves 

 the Mount Marcy sheet." 17 



In the Paradox quadrangle the same terrace is described by Doctor 

 Ogilvie : 



"The surface of this terrace is slightly uneven aud suggests an origin of a 

 kame terrace, which ice still stood in the valley. The front of this terrace has 

 heen extensively eroded in part by the Schroon River, which has built a lower 

 terrace of floodplain origin, and in doing so has worn back the face of the 

 older one ; in part by recent gullying. . . . The material of this terrace is 

 sand." 18 



Dr. William J. Miller has mapped a glacial lake — Lake Pottersville — 

 extending over the North Creek, Schroon Lake, and Paradox Lake quad- 

 rangles. 10 He says in part : 



"The best example of the sand flat delta deposit formed in the lake lies in 

 the vicinity of Pottersville (North Creek sheet). The highest water-laid sands 

 and gravels occur from one-third to two-thirds of a mile northwest of the vil- 

 lage and at an altitude of nearly 900 feet." 



Taking these figures together with the observations of the writer, the 

 different terraces noted strongly suggest that they were formed by the 

 same lake. The 900-foot delta at Pottersville and the 960 south of 

 Holiday Pond agree, assuming a deformation of 3 feet per mile. Thus 

 the writer has taken the liberty of using Doctor Miller's name for the lake. 



In the Ausable quadrangle, 2 miles northwest of Lewis, a series of 

 beautiful beaches is exhibited at the following heights : 920, 935, 952, 975, 



17 J. F. Kemp : N. Y. State Mus. Bull.. No. 138, p. 20. 



18 I. H. Ogilvie : N. Y. State Mus. Bull., No. 96, p. 477. 



19 William J. Miller : N. Y. State Mus. Bull., No. 170, p. 70, fig. 10. 



