Art. V] 



Carnky, Glacial Dam at Hanover. 



147 



Fic). 10. T.onking west from halt ". The hn^eled surface of halt 4 shows in 

 the middle distance; camera stands on the west slope of halt o. I'.arn on left 

 is in line with the Brick Plant. 



THE DELTA-LIKE TOPOGRAPHY OF PARTS OF THIS VALLEY DRIFT. 



As one approaches the Hanover Dam area from Newark, he 

 notes the strip of even sky-line, flanked by irregular horizons, 

 blocking" the valley (Fig'. 8). In ascending' the g'rade just east 

 of the Rocky Fork, gravel is conspicuous in the road gutters. 

 Having reached the summit, it is evident that "the top is nearly 

 plane.'' ' And looking eastward the second area of level topo- 

 graphy, near Boston Corners, tends to emphasize the resemblance 

 to a delta, or an outwash deposit "from the ice sheet into a body 

 of water held in the valley to the east." ' This second level strip 

 averages 10 to 15 feet lower than the first, thus the dam "de- 

 scends gradually eastward." ' Therefore the topography and the 

 surface materials suggest that "while the dam was accumulating 

 a lake probably occupied the valley to the east."* 



If this accumulation is otitwash material, delta-like in form, 

 then we would anticipate finding other but probably smaller del- 

 tas marking the mouths of valleys that were tributary to the area 

 involved by the static body of water extending eastward. During 

 the long interval since these smaller deltas, if any existed, were 

 built they must have suffered nnich from erosion and solifluc- 

 tion,' but not to the extent of being obliterated. We have studied 



' F. Leverett, ]oc. cit., p. 200. 



= Ihid., p. 200. 



» Ihid., p. 200. 



* IhUL, p. 280. 



^ J. G. Anderson, Journal of Gculoyy. Vol. XIV (1000), pp. 95-90. 



