No. 2.] SPENCER — COPPER-MINING. 81 



American friends will be a guide. Yet the metal must be paid 

 for, as riches cannot be picked up in the streets. 



On Isle St. Ignace, at Mamainse, Point Aux Mines, and on 

 Michipicoten Island, the copper-bearing rocks particularly re- 

 semble those on Keweenaw Point, and appear to be as promising. 

 Some small workings have been carried on on Michipicoten Island, 

 but these have not been sufficiently extensive to more than prove 

 the presence of copper in considerable quantities. In a report 

 of Dr. T. Sterry Hunt to the Quebec and Lake Superior Mining 

 Association, he speaks very strongly as to their probable value, 

 and from my own experience in the various copper mining locali- 

 ties on Keweenaw Poiut, and the comparative value of such 

 cupriferous rocks of Michipicoten Island as I have seen, I 

 look forward to the time when the development of these Canadian 

 mining localities will also be none of the least important of those 

 in the Lake Superior region — already the richest copper mining 

 region in the known world. 



Appendix. — After the former part of the present paper was in 

 print, Principal Dawson kindly referred me to a paper of his 

 published in 1857, relating to the cupriferous series in the 

 region of Maimanse, on the North Shore of Lake Superior. 



Although written at an early date in the history of geological 

 knowledge in that region, I was struck with the descriptions of the 

 rocks under consideration, and could almost have imagined that 

 he had a section of Keweenaw Poiut before him, so similar is 

 the lithological and geological structure in this locality to that 

 on the South Shore ; and I think the evidence quite sufficient 

 to prove the rocks both here and on Michipicoten Island to 

 be a continuation of the same part of the formation as is exposed 

 on Keweenaw Point. Moreover, Dr. Dawson considered the 

 proofs in the Maimanse region sufficient to establish from 

 stratigraphical grounds that the Copper-Bearing Formation was 

 intermediate between the Huronian and Potsdam (or the St. 

 Mary's) Groups ; which proofs have not been found further 

 west on the Canadian Shore. 



Again, the same writer points out the comparatively superfi- 

 cial volcanic character of the rocks of the Cupriferous Formation, 

 while those of the Huronian have a deep-seated origin 



At Maimanse aboriginal workings have been found, and several 

 years ago a shaft was sunk to a depth of twenty-seven feet, from 

 which three tons of copper were taken, one mass weighing 600 

 pounds. 



