658 H. L. ALLING GLACIAL LAKES OP CENTRAL ADIRONDACK^ 



ton Lake is, perhaps, at the present time the best understood of all these 

 local glacial lakes. It was confined in a general way to the East Branch 

 of the Ausable River and to the territory around the town of Wilmington 

 and stretches northward almost to Ausable Forks. 



The altitude is 1,100 feet at the foot of Johns Brook, in Keene Valley, 

 where a typical delta was developed. A mile and a half southeastward 

 of Keene, on the State road at Norton Cemetery, there is an excellent 

 display of a bisected delta. In the same vicinity a view can be obtained 

 embracing at one time successive terraces. They appear very distinctly, 

 showing Keene Lake, Newman Lake, Saranac water level, possibly the 

 Saint Hubert Lake, Wilmington Lake, and finally the Upper Jay Lake 

 at 1,000 feet. Unfortunately a photograph does not bring them out as 

 prominently as direct vision. 



As one investigates the terraces of the Wilmington Lake farther north, 

 in the Lake Placid and Ausable quadrangles, the altitude rises at a rate 

 of 2.94 feet per mile, and illustrates post-lacustrine deformation in a 

 clear and instructive manner. A number of beaches of the Wilmington 

 Lake are beautifully shown on a hill one mile directly north of Keene 

 Center. Here the altitude is 1,117 feet. Farther north we find the 

 outlet channel spillway at 1,140 feet. This level, compared with the 

 1,100-foot delta above mentioned, gives, on calculation, a deformation of 

 2.94 feet per mile. 



Cataract outlet channels. — When the outlet of the Wilmington Lake is 

 considered, we find a display of glacial phenomena which makes it one of 

 the most interesting regions of the Adirondacks ; for in the center of the 

 Ausable quadrangle, in a rather inaccessible country, a series of rock 

 channels culminating in a number of Pleistocene cataracts are very beauti- 

 fully shown. 



During the Wilmington stage an ice-lobe lay in the East Branch of 

 the Ausable with its southern wall a little south of North Jay. Another 

 blocked the narrow valley now occupied by Trout Pond. Tims northward 

 escape was prevented. The waters of the lake found their outlet to the 

 east through the gulf, a narrow and deep major fault, south of Ellis and 

 Black Mountains. The flow was through two unnamed little ponds, occu- 

 pying slight depressions in the rocky bed. One-eighth of a mile to the 

 east of them we encounter the first Pleistocene cataract of this remark- 

 able channel. Unfortunately the topography as drawn on the map is 

 defective and fails to show this feature. The crest of the now extinct 

 falls forms a beautiful horseshoe, some 80 feet across, with a drop of 

 50 feet. The cliff is not as precipitous as is the Jamesville Cataract, in 



