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Bulletin jf Laboratories of Denison University. Vol. XIIIJ 



No rock walls are exposed and the slope from the valley toj) is 

 uniformly gentle to the stream hed, which is an insii^niticant cut 

 in glacial dehris. Presumably this valley at one time contained 

 much more debris than at present, but this unconsolidated material 

 has permitted rapid erosion, lowering the stream to the gratle of 

 Spring Valley, and developing a valley similar to the original in 

 its upward slopes. One essential difference, however, is noted : 

 At the junction of this A-alley with Spring X'alley in a cut (C, 

 Fig. 1) through the flood plain which the latter has built across the 

 present mouth of the former is exposed compactly bedded de- 

 posits of blue and yellow clay-like material, located in what would 

 naturally be the bed of this tributary stream ; in places these 

 deposits are nearly homogeneous, showing little evidence of for- 

 eign gravels. Again, especially in some of the yellowish or brown 

 colored sections, ample evidence is found of foreign ])ebbles. 



At a point (F, Fig. 1) just north of this tributary to Spring 

 Valley, in the cut of the latter, the east rock wall abutting Spring 

 Valley and the rock bed of its stream is noted. Proceeding south- 

 ward the rock wall gradually declines forming the even north 

 slope of the tributary valley. For a short distance further the 

 rock shows but a few feet vertical ex]:)Osure in the cut of S])ring 

 \'alley flood plain. Then the outcrop becomes luore and more 



Fig. .1. Viow from lldod pl.iiii oi Si)riii,<i- N'.-illcy s(i(>aiii. lodkiiiir tiortli. S' 

 Captured drainage imw liilmtary to Spiiiii;- \alUy slri'aiu. A lOnliaiico 

 Spring Valley gorge. Uock outcrop shows to the Icl'l. 



