VOL. 34, 1922, PL. 4 



) 



Post Carboniferous granite 



Pennsylvanian 



fMississippian 

 / Devonian 

 [Silurian 



•'■•'••'•I I Cambrian 



Pre Cambrian 



200 300 Miles 

 I I 



_ Anticline 

 . Syncline 



A. KEiTH 

 1923 



LEGION 



/ 



