ME. J. H. COLLINS ON THE SUDBUEY COPPEE-DEPOSITS. 835 



sulphides with oxides and carbonates near the surface, solid copper- 

 pyrites with magnetic pyrites (pyrrJiotite) below. Blocks of nearly 

 pure copper-pyrites, weighing half a ton or more, were raised, and 

 about four thousand tons of ore were actually taken out and 

 shipped for smelting to New York, some assaying as high as 18 

 per cent, of copper, a stiU larger quantity, running only 3 or 4 per 

 cent., being rejected. As might have been expected, however, it 

 proved to be merely a rich bunch in a cupriferous belt, and not a 

 " mountain of ore." A shaft has been sunk following the dip of 

 the belt to a depth of more than 100 feet on what seems to be a 

 sort of ore-vein running diagonally across the belt, and levels have 

 been commenced right and left at various depths. A section of the 

 workings at the Copper-Cliff Mine is given in fig. 1. The mine is 



Fig. 1. — Section of Ore-deposit at Copper Cliff. 

 (Scale about 130 feet to 1 inch.) 



Cliff. 



N.W ' S.E. 





It 



a. Huronian deposits, h. Diorite. c. Ore-mass. s. Shaft on diagonal vein. 



connected with the Algoma branch by a siding about a mUe in 

 length, built by the Canadian Pacific Railway Company. 



At the Stobie Mine the ore-body has been exposed for a length 

 of several hundred feet, and to a depth of forty or fifty feet. By 

 means of bore-holes it has been tested to a further depth of 30 ft. 

 A section of this deposit is given in fig. 2. It was at first thought 

 that the ore dipped to the south-east, and the shaft shown at s 

 was actually sunk to a depth of 70 ft. at a point about 450 ft. 

 away from where the works were first started, in the assured ex- 

 pectation of coming upon mineral. As none was found, a bore-hole 

 was put down in the bottom of the shaft to a further depth of 

 80 ft., but still without success. Another bore-hole was then com- 

 menced much nearer the ore-body, and inclining towards it, 

 but stiU no ore was found, although it was carried to a depth of 

 200 ft. In fact, at the time of my visit, all the appearances were 

 in favour of the deposit dipping to the north-west, but very 

 steeply, as indicated by the section. 



