75° 10 

 38°55' 



50- 



45 - 



40 - 



38°30 



75° 10 



05 



— r- 



75° 00 



1 



55 



-I - 



75°50 



38°55' 



Contour Interval, 1 ft 

 I 



50 



45' 



40 



-35" 



75° 00 



74°50 



38.° 30 



Figure 16. Structure contour map of the pre-Holocene erosional drainage surface off 

 Delaware, modified after Sheridan, Dill, and Kraft (1974). 



45 



