368 H. L. FAIRCHILD — GLACIAL LAKES OF WESTERN NEW YORK. 



blasted for some distance in deepening the old canal for better drainage 

 (see figure 1, plate 21). 



In being narrowed and interrupted by morainic drift north of the 

 water-parting this large channel agrees with the smaller outlet channel 

 of the Naples lake, but does not agree with the channel of the Ithaca 

 lake. 



It is suggested that the relative altitudes of north and south portions 

 of this valley may now be somewhat changed from what they were dur- 

 ing the existence of the glacial lake. Northward differential uplift may 

 have raised Pine Valley somewhat; in other v/ords, it is possible that 

 Pine Valley may have been relatively lower during the life of the Wat- 

 kins lake, and the drift-hills have been partially submerged, the current 

 of water starting from a point so far below as not to seriously erode them. 



DEL T AS AND WA TER-LE VELS. 



On the west side of the valle}^, at Havana, is a delta conspicuous from 

 the village. Across the valley is the famous Havana glen, with a broad 

 delta showing on the higher ground, but not measured. The finest delta 

 is at Watkins, where Glen creek has cut the remarkable ravine after 

 bisecting its delta. The village cemetery occupies the slope of this de- 

 posit of gravel, which has several terraces. The summit is a flat gravel 

 plain more than a mile wide, with a measured height above the lake of 

 521 feet. Adding the lake height, 440 feet, gives the summit an altitude 

 of 961 feet, which is 61 feet above the channel of the Horseheads divide, 

 and 20 to 30 feet over the broad flood-plains bordering the channel. A 

 small terrace occurs at 917 feet; a strong terrace at 883; another broad 

 plateau, which is the upper field of the cemetery, at 790. These were all 

 measured upon the north side of the ravine. Apparently another ter- 

 race occurs at 760 feet upon the south side of the glen (see figure 2, 

 plate 21). 



During another season of field-work careful measurements will be made 

 of other deltas and the levels compared. Doubtless many stream deltas 

 along the lake will show summit plateaus at a plane corresponding with 

 the expanded summit of the Watkins delta, but the full correlation, of 

 the lower terraces cannot be so confidently expected. 



LAKE HISTORY. 



Coalescent Waters called Lake Newberry. — While the water rested at the 

 highest level, something below the summit plateau of the Watkins delta, 

 it had a general depth over the Havana plain of 500 feet, and over the 

 site of the present lake of 1,000 feet. The local lake must have attained 

 a length of thirty to forty miles, with a breadth of perhaps five miles, 



