REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1900 rl29 



harder shale, which heads in a smooth, swampy col 1 mile north- 

 east of Fayetteville. The flat bottom of the channel is from 20 

 to 30 rods wide, the breadth on an upper or flood plain level, a few 

 feet higher, is some 40 rods. Nearing Round lake, the channel 

 bottom becomes Y shaped, and falls about 120 feet to the lake 

 level. 



These lakes certainly lie in the course of an ancient river 

 channel. The argument for their origin is the same as that 

 applied above to the case of the Evergreen lake. If the streaim, 

 did not produce them, then it could have been only some subse« 

 quent agency. Solution and subsidence afford the readiest sug- 

 gestion. A serious fact against this last suggestion is that the- 

 depth of the lakes is too great to be caused by solution of all the 

 thickness of salt ever held in the underlying strata. We miust 

 regard the basins of Round and Green lakes as a type of cataract 

 basin in soft shale, while those of Jamesville and Blue lakes- 

 represent the type in limestone. 



The ice front 



Position and form. As the stream channels cutting across the 

 north ends of the ridges were held there by the frontal edge of 

 the glacier^ the attitude, form and relationship of the channels 

 give us some knoiwledge of the position of the ice front at the 

 time the channels were cut, and of its order of recession. 



The well known habit of the glacier to follow the valleys or to 

 push farther up the low ground is shown by the curving form of 

 the channels. The higher channels on Eagle, West Stockbridge 

 and Eaton hills show a decided curvature around the ends of the 

 ridges (pi. 16). As these channels either laved the glacier front 

 or were very close to it, the fact is evident that the ice had 

 reentrant angles at the ridges with projecting lobes in the 

 valleys. 



Order of recession. The channels were certainly cut by east- 

 flowing waters. It is evident, therefore, that the receiving water 

 at the east of any particular channel must have been lower than 

 the mouth of the effective channel. The falling of the dammed 

 waters was consequently from the east toward the west. This 

 m^ans that the ice front receded or backed away from the escarp- 



