PLATE XVI 



Sketch map of the vicinity of Easton, Penna., showing the occur- 

 rence of serpentine and talc and their relations to the main geologic 

 features of the region. 



gn = pre-Cambrian gneiss, gr = granite, xxx = augite syenite. 



The principal occurrence of talc and serpentine are at points num- 

 bered I to 7 and are represented by thickenings of the fault lines. 



A-B, etc., are fault lines. 



I and II are lines along which sections are taken. See figs. 4 and 5 

 on pages 420 and 426 of text. 



(430) 



