REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1903 101 



of the territory now covered by Lake Ontario; and though much 

 •of the glacial drift is made up of fragments of Medina sandstone, 

 it is generally conceded that much of the erosion of this formation 

 was accomplished by a preglacial riyer. The Salina deposits, on 

 the other hand, have a shallow yalley at one part and a deep valley 

 near by ; and the presumption is that, if the deeper valley was 

 made by glacial actiion, the shallow valley west of Rochester should 

 be deeper, as it was exposed to glacial action longer than the 

 Finger Lake region. In case the shallow valley was the result of 

 glacial action, it still remains a question why the action should 

 have been greater in the Finger Lake region. An examination of 

 the Hamilton deposits shows no marked valley, and, as this form- 

 ation was exposed to glacial action and is fully as soft as the 

 others under consideration, it becomes almost certain that the 

 Salina valley was not the result of glacial action. 



The changes in level which these strata have undergone render 

 it very difficult to determine with exactitude the direction of the 

 ancient river, as it is supposed that the Finger lakes were formed 

 in preglacial times by streams flowing south. The existence of this 

 deep valley at the outlet of these lakes, however, leads the writer 

 to suggest that at a stage between the time when the rivers flowed 

 toward the south and the glacial epoch, the rivers in the Finger 

 Lake valleys flowed into the Salina depression and thence through 

 the Mohawk river. 



While this valley was being formed, this part of the State was 

 considerably higher than at the present time, as is shown by the 

 fact that the bottom of the valley at Syracuse and the deepest 

 part of Lake Ontario are below sea level, and valleys are not cut 

 below the level of the outlet of the streams. 



It is probable that the solvent action of water has had much 

 to do with making this depression, and, if the existence of de- 

 posits of salt in this section could be proved, this would undoubt- 

 edly be a most logical explanation of the formation of cer- 

 tain parts of the depression. The existence of salt, however, in 

 this region, is only a matter of conjecture, but in the region south 

 of this, it is found in almost all cases where wells have been 



