Art. VI 



Carney, Glacial Dam at Hanover 



145 



uiululatiiii;-, rarely liavin_q- a vertical rant^e of 20 feet. The sur- 

 face material is rather hne, and as revealed in sections is some- 

 times water-laid ; unassorted sections also appear. The hic^hway 

 leadin^:;" north from the I'rick Plant crosses four distinct channels 

 (Fig. I»). which have neither the form nor the relative location 

 of normal erosion channels ; they are interpreted as made hy ice- 

 front streams. East of the highway, and ahout half the distance 

 between the Brick Plant and the first road leading eastward, 

 the drift assumes a sharp morainic aspect. The level-topped area 

 west of the highway continues northward in the valley extending 

 into Perry Township ; here too the delta-like appearance blends 

 into more irregular forms of the drift, suggesting intervals of re- 

 treating and stationary ]X)sitions of the lateral tongue wdiich fed 

 into this side valley. 



In eastward continuation we have next another interval of 

 descending contours (Pig. l'>) , denoting a period during which the 

 melting factor was greater than the ice-feeding factor. Here the 

 Pennsylvania railroad swings northward towards the sag be- 

 tween the ice margin and the valley wall. In doing this the rail- 

 road has made a cut about one-half mile long and oO feet in maxi- 

 nuim depth. The great amount of clay in the drift has necessi- 

 tated a wide cut and frequent cribbing. The region of this cut, 



FUj. .0. View from the hill south of the Bi-ifk Plant looking northwarfl. Most 

 of the area shown is the tiat-topped interval between halts 4 and •'"). The middle 

 distance shows this tlat area extending into the tributary valley northward. The 

 ice-front channels appear along the highway leading north. 



