r36 NEW YORK STATE MUSEUM 



apparently had a trend oblique to the south border of the basin, 

 thus making an open angle toward the east. The ice front there- 

 fore receded from the higher ground progressively from east 

 to west. In consequence of this oblique position and westerly 

 recession of the ice front, the eastern channels were cut earlier 

 than the more westerly channels of corresponding levels. It 

 follows that the several low level channels which we are con- 

 sidering in this paper are not all of one series. The channels 

 toward Rome are to be correlated with some of the high level 

 channels toward Syracuse, described in earlier papers, while 

 the low level channels near Syracuse probahly poured their flood 

 into the primitive Lake Iroquois, which then occupied the low 

 ground toward Rome. 



The final outlet of all the glacial waters was over the col at 

 Rome to the Iroquois river and the Mohawk valley. As the ice 

 front receded from Rome the lake (Iroquois) was initiated, and it 

 enlarged at the expense of the glacier till it filled the Ontario 

 basin. 



The channels which have an altitude over 445 feet were always 

 above the lake level. Those toward Syracuse with altitude 430 

 feet and lower probably poured their waters at first directly 

 into the forming lake, and later may have been flooded by the 

 lake. This topic is discussed in the next section. 



Altitude and deformation of the channels 



The present hights of the channels above sea level are indicated 

 by the map contours (pi. 8-10). It will be observed that the alti- 

 tudes do not decrease toward the east as might be expected. On 

 the contrary, the highest channels are those beyond Oneida, 

 while the lowest are those at Syracuse. There are two causes of 

 this discrepancy. The most important is that the several chan- 

 nels are not of one series, but were cut at different times and in- 

 dependently of each other. The second cause is that the absolute 

 and the relative altitudes of the channels are not quite the same 

 now as when they were made. Since the ice retreat the land 

 surface of the region has been uplifted and possibly warped. 



