REPORT OF THE DIRECTOR IQII, 155 



dipping to the north with the country rock. At present ore bodies 

 lying at two distinct horizons, separated by about a thousand feet 

 across the strike, are worked, and the superintendent of the mines, 

 Mr J. Tonkin, informed the writer that a total of nineteen ore 

 bodies of varying thickness had been shown by diamond drilling. 

 According to Mr F. T. Rubidge, vice president of the St Law- 

 rence Pyrites Co., to whom the writer is indebted for many courte- 

 sies, only four or five of the pyritiferous horizons afford workable 

 ore-bodies. They run about twelve feet in thickness, but may reach 

 as high as" thirty feet. In the Stella mine, the ore, about ten feet 

 thick, extends about eleven hundred feet along the strike and has 

 been worked nine hundred feet down the dip of 20°-30°. Con- 

 siderable pyrrhotite occurs in this mine. In the Anna mine, the ore 

 averages twenty feet thick and has been followed two hundred fifty 

 feet down a 45° dip and twelve hundred feet along the strike. As 

 elsewhere, the ore bodies are not sharply defined but fade gradually 

 into the surrounding rock, which is impregnated with pyrite some 

 distance from the ore proper. While the typical ore lies in the rusty 

 gneiss, pyrite is disseminated rather generally through the rocks, 

 and railroad cuts in the hornblendic gneiss south of the mines show 

 strongly pyritiferous masses of irregular form, the pyrite being in a 

 , tough dark base. The same rock is also cut by many bands of 

 I pegmatite, both parallel to and across the foliation. These bands 

 I frequently carry pyrite in crystals and it also occurs in irregular 

 branching veins in the gneiss. 



1 The gneisses above and below the upper ore body carry a great 

 deal of sheared pegmatite, mostly parallel to the foliation, and this 

 'carries some pyrite. Thus here, as elsewhere, the pegmatite is con- 

 spicuous. The same is true of graphite, for just as at the Cole mine, 

 iche tailings from the concentrator carry considerable amounts of this 

 I mineral, which also is more abundant in the ore and immediately 

 adjacent rocks than farther from the ore bodies. 



Hand specimens of the ore show a granular aggregate of pyrite, 

 Graphite and a gray, soft alteration product, together with some 

 quartz and feldspar (see figure 17). Some specimens can hardly be 

 distinguished from the material at the Cole mine but large crystals 

 ire less frequent at Stella.. 



j Here and there vugs occur, lined with crystals of quartz, calcite 

 and sphalerite, manifestly much younger than the pyrite and formed 

 mder quite different conditions. 



