26 NEW YORK STATE MUSEUM 



When the ice front stood at the line of the moraine the streams 

 of water issuing from it and carrying debris from the melting ice 

 deposited their excess of load beyond the edge of the ice. The 

 waters emerging from the western end of the ice front, following 

 the lowest course open to them, occupied the preglacial drainage 

 valley in this portion of the basin. These waters, through deposi- 

 tion of sediments, gradually filled in this valley, thus developing an 

 aggradation form. The form may have been of the type of a valley 

 train, or an outwash plain, or of a grade between the two, accord- 

 ing to the spread of the materials deposited, as dependent upon the 

 width and slopes of the valley, the number and places of issue of 

 streams from the ice front and other factors. In the early stages 

 of its building its surface sloped toward the south (down stream) 

 because the process of aggradation was most rapid near the ice 

 where the coarser materials were laid down and slower below where 

 the finer materials were deposited. The further aggradation of the 

 plain (it is now approximately level) may have taken place at a later 

 time, that is, after the ice front had withdrawn from the line of 

 the moraine. It is probable that this aggradation plain represents 

 an accumulation of deposits laid down during different stages of 

 the drainage of the region northward to the plain. 



Besides the plain just described there are two other level tracts 

 bordering the moraine at its southern margin. One of these is 

 the swampy area forming the reentrant between the first and sec- 

 ond morainal lobes and, as suggested above, may represent an ice 

 block hole. It seems probable also that with the melting of the ice, 

 sands were washed in from the debris of the moraine and spread 

 over the area. The third level tract extends southwestward from 

 the point of the third lobe of the moraine. Its surface materials 

 are in general sand with a veneer of vegetable mould. A consider- 

 able portion of the area is swampy. It bears the topographic rela- 

 tions of an outwash plain to the moraine and while not a typical 

 formation of this character, it has been thought warrantable to so 

 represent it on the map. 



Lake Corinth deposits. The village of Corinth stands at the 

 border of a sandy tract that extends northward beyond the edge 

 of the sheet and southward to the northern border of the moraine. 

 In its southern portion the tract broadens eastward, attaining a 

 width of about 3 miles. The area is generally level except as cut 

 by water courses, the present average elevation being about 640 

 feet. In the southeastern extension a portion of the plain shows 



