THE MINING AND QUARRY INDUSTRY I915 79 



ZINC 



The progress of the interesting developments in zinc mining at 

 Edwards, St Lawrence county, has been described in previous 

 issues of this report, and a brief account of the ore occurrences and 

 their geological surroundings was included in the issue for 1912 

 (Museum Bulletin 166). During the past year productive opera- 

 tions were begun, resulting in the first shipments of zinc ores on a 

 commercial scale that have been made by any enterprise within the 

 State. 



The source of the production, which amounted to a few thousand 

 tons of blende concentrates, was the mine of the Northern Ore Co., 

 situated just outside the village of Edwards on the road leading to 

 Trout lake. The property, with showings of ore at the surface but 

 unprospected at the time, was acquired by the company over ten 

 years ago. Owing to the unusual character of the deposits, 

 scarcely comparable in their geological relations to any other bodies 

 of zinc ores now mined in this country, the conduct of the early 

 exploratory work could hardly be guided by experience with 

 similar ones elsewhere, and it was essential to adopt a conservative 

 policy in the development and equipment of the property. In the 

 past year the workings have been extended to a depth of about 500 

 feet, following a lens of ore that is inclined 25°-6o° from the 

 horizontal. There are no indications on the lowest level of any 

 change in the geological conditions which might lead to the inter- 

 ruption of the ore-bearing ground and the discontinuance of the 

 deposits ; on the contrary, the conditions seem favorable to the 

 extension of the ore beyond the depths attained up to the present 

 time. 



So far the Northern Ore Co. has worked only one shaft, near the 

 south line of the Edwards property, that follows a vein or lens of 

 solid blende and pyrite, about 5 feet thick at the surface, swelling 

 to 14 feet at the 150 foot level and thinning again where seen in the 

 300 and 400 foot levels. The longest levels are about 600 feet on 

 the strike of the ore. The ore body to the south of the shaft curves 

 around in a broad arc, so that at the extreme end of the working 

 stopes the direction of dip is southwest or at right angles to that of 

 the shaft itself. Swells and pinches occur frequently, and stringers 

 of ore occasionally branch off from the main body. There is much 

 resemblance in the shape of the deposit to the form assumed by 

 some of the magnetites in the harder crystalline rocks of the 

 Adirondacks. A second lens of ore shows at the surface to the 



