BY LEO A. COTTON. 



759- 



was earlier than the " Acid Granite " system, and may have been 

 contemporaneous with the intrusion of the latter granite. 



N.B. — The bearings in the tables are all measured clockwise from the 

 north azimuth, which is taken as 0^ or 360*^. 



Having now discussed the distribution of the lodes, and their 

 relations to the systems of fracture, the next important con- 

 sideration is the nature of the ore-deposits. 



Nature of the Ore-Deposits. 



It is not the purpose of this paper to discuss in any detail the 

 genesis of the ore-deposits, but rather to lay the foundation for 

 such a discussion by a faithful record of their field-occurrence. 

 It would be premature to attempt any such discussion without 

 chemical and microscopical investigation. It is my desire to 

 undertake this important phase of the work after having 

 examined the deposits at Emmaville. 



The question arises whether a classification should be uiade 

 upon a morphological basis, or upon the nature of the vein- 

 material. The usual method is the former, in which a classifica- 



