REPORT OF THE DIRECTOR 1919 59 



History of the Tioughnioga river. Up to this point the dis- 

 cussion, with the exception of the emphasis put upon the notable 

 succession of the glacial series features found in the area and the 

 regional descriptions, has not involved anything especially novel in 

 the interpretation of glacial phenomena or physiographic history. 

 The reader has, however, now been sufficiently informed in regard 

 to the general succession and relation of the features exhibited, to 

 be in a position to appreciate a set of conditions which have given 

 the course of the Tioughnioga river peculiarities that have unusual 

 significance in the interpretation of the last phases of the glacial 

 development of the area. 



The Tioughnioga river has its source in Big lake of the Tully Lake 

 group. Probably Crooked lake and Long lake also underdrain to ir, 

 for they stand at a slightly higher level than does Big lake. Refer- 

 ence to the topographic map will reveal the fact that almost immedi- 

 ately after leaving the Big lake source the course of the river bends 

 sharply over to the east valley wall of the outwash plain and con- 

 tinues to parallel the valley side for several miles. In this section, 

 parallel to the valley and alongside the improved state highway, the 

 river cuts directly into the rock wall of the larger depression. Then 

 the stream passes through Little York lake, meanders for some miles 

 over the valley train deposits and next, opposite Homer, it agani 

 swings sharply against the east valley wall. What is the significance 

 of these two swings with a course close up against the bedrock of 

 the valley side in each case? 



Reference to the photograph of the relief model of the region 

 (plate i), in conjunction with use of the topographic map will 

 make it evident that the place where the first of the swings occurs is 

 just opposite the mouth of the Otisco lake through valley, marked 

 at its end by the village of Preble. Similarly the swing at Homer 

 is the end of the Skaneateles lake through valley. Both of these 

 lake valleys have a history equivalent to that of the Onondaga valley. 

 They are glacially eroded troughs even more deeply and sharply in- 

 cised by the ice than the Onondaga valley. 



Apparently, also, they were occupied longer by the ice than was the 

 Onondaga valley. This might be expected since they were more 

 directly in line with the axis of the ice advance, as pointed out earlier, 

 and were cut deeper and straighter; hence they could hold a more 

 actively supplied and deeper lobe of ice during the retreatal stages. 

 But more significatit than such inferences is the fact that beyond 

 the south end of each of these valleys there is spread a wide fan of 

 outwash material, which lies higher on the west and slopes off in 



