146 Agricultural Experiment Station, Ithaca, N. Y. 



• 



disappearing just south of Hamburg, the others extending to the 

 vicinity of Crittenden where they also die out. Without analyzing 

 my measurements here, it may be said that the crest of the first or 

 lowest beach ranges from 15-20 feet above the base of the terrace ; 

 the second beach ranges between 10-16 feet above this ; the third 

 from 10-15 feet higher; the fourth also 10-15 feet higher; and the 

 fifth between 30-40 feet above this. As one drives along the main 

 road to Buffalo, the face of the upper terrace is frequently visible, 

 while the road itself is usually upon either the lowest, or, more com- 

 monly on the second level. From just west of Silver Creek to within 

 three miles of Fredonia, it follows the lowest ; but west of this is 

 more commonly on the upper level, though at times descending to 

 the lower. When visible, the third and fourth beaches (measured 

 from the base) are indicated by slight gravel ridges. There is so 

 much variability in these respects that to make the feature entirely 

 clear it would be necessary to describe the region in much detail. 

 From figure 67 one will obtain an idea of the irregularity of level, 

 throughout which, however, there is considerable uniformity. 



Below the upper terrace there is usually a bench or plain which 

 slopes quite uniformly up to the base of the terrace and on the 

 northern margin ends in a steep descent ; but in a number of places 

 this plain is diversified by slight benches of gravel, marking some 

 of the intermediate beaches. From the crest of the upper terrace 

 toward the south there is also a plain, which is usually very narrow, 

 but is sometimes gradually merged into a broad till-covered plain 

 (Fig. 54). 



From the lake shore to the base of the first gravel ridge, near 

 the main road, there are no beaches of a distinct character, although 

 in one or two places there are indications of wave action. Over 

 this plain, which is often one or two miles in width, the soil is 

 mostly of clay, as has already been noted. However, north of the 

 town of Portland there is an ancient sand dune region, in which the 

 sand is no longer in movement, having probably had its features 

 introduced immediately after the lake water left the land. The 

 sand is fine in texture, quite like moulders' sand, and it is heaped 

 into the typical conical peaks with enclosed craters, which char- 

 acterize sand dune belts. Here the topography is very rough ; but 

 elsewhere the prevailing condition is that of a plain, sloping lake- 

 ward. 



