DEEP MINING IX NOVA SCOTIA — PREST. 427 



amount of (jiiartz than tlie complete absence of gold Of the 

 streaks we will speak farther on. 



The mineralization of our gold -bearing leads seems to have 

 taken place during the folding process and before the formation 

 of the cleavage planes. The different seams composing them 

 show a somewhat interrupted mode of formation while polished 

 and striated surfaces show that the folding and consequent 

 earth movements were not complete when the deposition 

 of vein matter began. Those veins were of course then far 

 below the surface of the folds. The auriferous zone of Mt. 

 Uniacke for instance was over 20,000 feet below the upper 

 slates, and could one of our pessimists have been there at that 

 time he would have declared that no gold existed there, and that 

 deep mining was useless. 



The hydro-therinal theory of the origin of mineral-veins now 

 so widely upheld and based on so many well knov>^n facts ac- 

 counts (as far as my opportunities for knowing go) for every 

 peculiarity of our gold-bearing leads. The hot springs of 

 California and the Yellowstone Park in which many minerals 

 are now being precipitated reach down without doubt to the 

 great internal source of heat and are active examples of the 

 hydro-thermal mode of mineralization. If this theory accounts 

 fcr our pay streaks, which is very probable, I see no reason 

 wdiy they should not reach down as far as it is possible for 

 mining to be carried. We have in Nova Scotia men who while 

 convinced of former hydro-thermal action in our auriferous 

 veins, yet give voice to the idea that they are, comparatively 

 speaking but surface deposits. 



xMetamorphism. 



To the metamorphic influences of the early Devonian must we 

 ascribe the origin of the gneisses, schists and diorites and much 

 if not all of our granite. We may define the granite as the 

 molten nucleus by which the metamorphosis of our Cambrian 

 and Silurian rocks was brought about or we may class it as a 

 result of the fusion of our stratified rocks. The latter seems to 



