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



river or Middlesex valley gave a northeast channel toward Stanley. As 

 the waning ice-sheet thinned and weakened over this divide, masses of 

 the front were probably lifted and removed by the buoyant water, and 

 lower outlets along the ice-front were thus opened rather suddenly. This 

 probably accounts for the several unusually distinct terraces upon the 

 deltas. 



It is possible that for a time the waters flowed northwest through 

 Honeoye valley, if the ice-blockade was removed there earlier than over 

 some particular level south of Stanley, but the col between the Canan- 

 daigua and Honeo3^e valleys has not at this writing been examined, and 

 that question will be considered in a future description of the Honeoye 

 glacial lake. 



The lowest terrace is thought to represent the level of the great water 

 which united all these local lakes until the Mohawk outlet was opened. 



The Hammondsport Lake. 



keuka valley, 



The glacial lake which formerly filled this valley to southward over- 

 flowing had on account of the simple character of the geography a 

 comparatively plain history. The lake is eighteen miles long, one mile 

 wide, and is forked at the north end. Its depth at the southern end 

 averages about 160 feet. The walls rise abruptly for about 500 feet, and 

 more gently to a height of 1,000 to 1,200 feet above the present water 

 surface. Through these high walls of the plateau there are no breaks, 

 except at the two ends of the valley. The lake level is preserved for two 

 or three miles in low, swampy land, characteristic of the heads of the 

 linear lakes, to the point where moraine-kame filling begins, which ex- 

 tends four miles further. The south end of the valley is chiefly drained 

 by Inlet creek, about six miles long, with its many tributary brooks. At 

 the head of the lake two smaller streams have cut ravines, one on either 

 side of the valley, the Laughlins Glen brook coming from the east and 

 joining the inlet near its mouth, and the Glen brook from the west flow- 

 ing through the village of Hammondsport, which lies against the south- 

 west corner of the lake, and debouching directly into the lake. 



DIVIDE. 



The glacial outlet was over the moraine and kame filling of the south 

 end of the valley, which begins about three miles from the lake and con- 

 tinues four miles to near Bath, where it becomes an overwash gravel- 

 plain. The general height of the divide is about 1,150 feet above tide. 





