I82 



H. C. COOKE 



The succession in this area is: 



Rhyolite porphyry lavas 



Intermediate lavas 



Andesites and andesite tuffs at or near the top of the flows 



Dip ^nd Strike 



Fig. 4.— The Opawika area 



It seems possible that the structure of this whole belt is that of 

 a synclinorium, as the uppermost beds are found only near the 

 the median line of the belt. However, this distribution may equally 

 well be due to irregularity of original deposition, more especially as 



