35 



the silver discoveries have been made. The silver is found 

 in fissures in this rock near the intrusions of Keweenawan 

 diabase, and in some cases the veins have crossed the dia- 

 base as well as the slate. The dark colour of the slate is 

 largely due to the presence of carbonaceous matter which 

 is thought to have been an important factor in the pre- 

 cipitation of the silver, for the silver is said to be always 

 accompanied by carbonaceous matter. 



S79.tf.l. above Lake Sr(/ierior 



Drift banddtis 



msm 



mhm 



^—~~ LZTr-^^—^-^Sb^ TaUts thtefly trap, blocks 



Trap Can 



Section through Mt. McKay near Fort William, Ont. The trap here bears a similar 

 relationship to the slaty series to that which it has in the Cobalt area. Some 

 silver veins in the Port Arthur area cut both the trap and the slate. (After Dr. 

 A. C Lawson.) 



The most noted mines of this vicinity are the Silver 

 Islet, Silver Mountain, Beaver, Badger, and Porcupine. 

 None of these have been worked to any great extent since 

 the fall in the price of silver in 1892. 



Itinerary. 



At Current River park the Keweenawan traps and over- 

 lying slate are first noted. Usually the slate is not more 

 35069— 3^ 



