DEEP MINING IN NOVA SCOTIA — PREST. 433 



1 2,000 feet in Caribou has reached a paying auriferous zone, 

 while an erosion of about 25,000 feet in Mount Uniacke has not 

 gone beyond it. Between those limits lie the paying portions of 

 tlie gold-bearing zones of nearly all the other mines. 



Some facts showing the existence of rich spots both above and 

 below the present surface are as follows : — 



At Killag, by far the richest parts of the leads have apparently 

 been swept away. At Fifteen Mile Stream the richest parts of 

 the Orion and Serpent leads have been carried away. The same 

 may be said of the Cumminger lead of Mooseland and the Prest 

 lead of Upper Cornwall and many others. Other rich spots 

 have been reached only by deep mining, as for instance in the 

 Stuart mine in Caribou. 



Our deepest mines have reached a vertical depth of not much 

 over 400 ft., the pay streak where present, being followed on an 

 incline of course considerably farther. Some, like the Lake 

 Lead of Caribou, once considered worked out, have been again 

 attacked under new and energetic managers and promise a 

 bountiful return for the future. 



A reconsideration of the evidence as far as I have been able to 

 collect it, seems to justify the following conclusions : 



Lst. The probability of the hydro-thermal origin and resulting 

 great depth of our mineral veins and pay streaks. 



2nd. That the original was far above the present surface and 

 even the upper beds of the series in question show evidences of 

 great erosion and still higher beds. 



3rd. That what are now called surface deposits were then 

 many thousands of feet deep. 



4th. That denudation (or geological deep mining) has already 

 exposed our pay streaks to a depth of 25,000 ft. below the 

 original .'^urface. 



5th. And finally, modern mining has only exposed those |>ay 

 streaks oOO or 600 ft. lower down, thus only slightly extending 

 the former geological work. 



When the question of deep mining is fully considered in all its 

 varied geological relations, I cannot see why there should exist 

 any doubt as to its successful prosecution. Judging future 



