﻿Plate 30 





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Location map showing by the dotted belts the distribution of Inwood lime- 

 stone in the Hastings-Yonkers district and the position of the Bryn 

 Mawr tunnel section as well as shaft 13 on the New Croton aqueduct 

 with their relations to the limestone belts. Manhattan schist and Ford- 

 ham gneiss occupy the rest of the area. 



