35 2 



FREDERICK W. SARDESON 



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site. The glacial drift has not, there- 

 fore, its original thickness. Twenty 

 feet or more of it have been washed 

 away by the river, and should be restored 

 in interpreting the glacial work in this 

 particular case. In other respects, the 

 accompanying profile explains itself in 

 the"main. [Below the soil and peat (P) 

 is terrace sand, T, with the shells of land 

 snails, Helix, et al., in it, and the river 

 shingle, R, with TJnio shells. Still lower 

 is the glacial till, G x and G 2 , overlying 

 beds of the Galena (Trenton) series. Of 

 these, the first (lowest) bed, B I} and 

 the second, B 2 , are massive limestones. 

 The lower part of the third bed, Sa, is 

 also limestone, but is distinguished by 

 its color, and hard, pyritiferous, crystal- 

 line condition. The upper part, Sb, 

 consists of several layers of grayish 

 crystalline limestone, separated by 

 uneven clay-shale seams. Sc (at the 

 right of Fig. i) is clay-shale, overlain by 

 limestone, d, belonging to the same third 

 bed. Sa to Sd comprise about half of the 

 third bed of the series, as seen elsewhere 

 in the vicinity. The upper part, here 

 wanting, is shale, with thin and widely 



•£ J '§ separated layers of limestone. 



•5 £ ^ On the right (southeast) of the section 



there are three remarkably glaciated sur- 

 « faces, X 2 (top of Sb), X 2 (top of bb), 

 , and X 3 (base of bb), one above the 

 ^ other. It is this phenomenon, noticed 

 more than ten years ago, which led me 

 to study this locality. At that time the 

 part of the profile which is represented 



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