432 DEEP MINING IN NOVA SCOTIA — PREST. 



The position of our gold-bearing zones in regard to the anti- 

 clines are as follows : — 48 are on or very near the apex of anti- 

 clines ; 11 are from | mile to 3 or 4 miles from the apex, with a 

 few of uncertain position. 



It must be remembered that the proximity of a lead to the 

 anticlinal apex is no certain evidence that it is gold bearing. Its 

 position in regard to tlie apex is simply a geological accident 

 depending on the size of the fold and the amount of erosion it 

 has suffered. For example, we can see that had erosion not 

 extended so far the auriferous zone of Renfrew would have been 

 nearer the anticlinal apex, while Mount Uniacke, Caribou, Golden- 

 ville and numerous others would have been hidden from sight 

 beneath their anticlinal coverings. Again, had erosion been 

 carried several thousand feet deeper the gold bearing zone of 

 Renfrew would have been removed much farther from the apex 

 than it is now, while Caribou, Goldenville and Mount Uniacke 

 would probably have borne the same relation to the apex that 

 Renfrew now does. 



Or, to explain my meaning more thoroughly, Mt Uniacke, 

 according to an old survey, has a north dip averaging 60*^, and a 

 south dip averaging 90^, and an anticline inclining north about 

 75". Assuming that the paying leads extend 600 ft. south of 

 the apex, they would meet and fold over it at a height of 2,318.2 

 feet. However, as the sharpness of the apex generally decreases 

 with its increase in geological height, the leads would curve over 

 the anticline and be covered by succeeding layers before reaching 

 the height mentioned. An auriferous zone which was once 

 hidden from view in the depths of the anticline is first laid bare 

 by denudation, and then removed farther and farther from the 

 apex with every successive period of erosion. Therefore the 

 distance to which the auriferous zone has been removed from the 

 apex of the anticline marks the stage to which denudation has 

 been carried. That tlie distance to which a lead has been 

 removed by erosion has nothing to do with its poverty or rich- 

 ness is seen in Renfrew, South Uniacke, VVhiteburn and Kempt 

 That the depth to which it has been eroded does not mark its 

 richest spot is slio\v n by the fact that an erosion of 10,000 or 



