256 The Parallel Drift-Hills of Western New Yorh. 



From numerous obsei'vations upon recently cleared lauds, I 

 should judge the relative i:)roportions of the different rocks re- 

 presented to be as follows : Medina, crystalline, Hudson River, 

 Kiagara, Clinton. 



The surface soil of the upland along the Niagara outcrop, and 

 for some distance south, is commonly of sandy loam, Avith boul- 

 ders freely interspersed. Far down upon the Salina, and north 

 toward Ontario, it is clayey. The soil of the valleys is of course 

 much more variable, depending greatly upon the extent to which 

 it has received the wash of the neighboring hills. All the 

 swampy valleys have superficial deposits of muck or peat, while 

 many, somewhat better drained, contain beds of brick-clay. 



The surface soil of the uplands is from a few inches to a foot 

 or two in thickness. Underneath, and separated from it by no 

 well-defined line, is a deposit of far different character. This is 

 a compact, tough, generally red, clay, filled with small glaciated 

 pebbles and boulders. South of the Niagara outcrop, the in- 

 cluded pebbles and boulders are almost entirely of the dark-blue 

 hard Niagara limestone, while north of this line they are of 

 lower rocks. In this clay, are no evidences of true stratification, 

 though examples of a rude a'ssortment of its materials are not 

 uncommon. Some of these have been afforded in sinking wells. 

 One case occurs to my mind, of two wells having about the 

 same depth, a few rods apart, tapping the same i-eservoir, so 

 that in dry times the upper may be drained by pumping out the 

 lower. In this instance, the water-bearing layer is a coarse 

 black sand, quite unlike the overlying clay, and was struck about 

 twenty feet below the surface. 



Numerous springs occurring on the hillsides also attest the 

 rude assortment of these drift materials ; for where the clay 

 occurs in its typical character, it is almost as impervious to 

 water as a rock. 



This clay, with its included stones, is, in short, a typical 

 boulder clay or till. Though I have described it as found in 

 the uplands, excavations in the valleys show it in precisely the 

 same character, though of course its superficial covering is quite 

 different. An observation Avhich I made last season will illus- 

 trate this point. After passing through two feet of muck, six 

 inches of yellow sandy clay, six inches of washed gravel, and 



