102 ^EVV YORK STATE MUSEUM 



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There is considerable variation in the proportions of the two 

 minerals, though blende is much the more common and in some 

 parts of the deposit is practically the only ingredient. Assays of 

 the richer material shoAv from 40 to 50 per cent zinc. The blende 

 is black, nontransparent, and apparently carries relatively large 

 amounts of iron. 



The general features of the ore occurrence in the Edwards section 

 were presented in the issue of this report for the year 1905, but 

 in view of the discoveries that have since been made, it may be of 

 interest to enter upon their discussion here. 



The existence of* the zinc in this part of St Lawrence county 

 has been know^i since the early part of the last century and is 

 mentioned briefly by Ebenezer Emmons in his Report on the 

 Geology of the First District, published in 1838. Some attempts 

 were made to work the ores in the early days, as shown by the exca- 

 vations on the Balmat property wdiich are said to have been under- 

 taken for the purpose of extracting the lead and silver values rather 

 than the zinc. The intimate mixture of galena, blende and pyrite 

 proved no doubt a rebellious material to treat by the methods then 

 available ; at any rate mining was soon abandoned. The present 

 interest in the deposits dates from about 1902 when the attention 

 of local mining men w^as attracted to some specimens of rich blende ^ 

 that were uncovered in the Edwards locality about 12 miles north- 

 east of the old Balmat prospect. These appeared so promising that 

 leases were secured on the property and work was begun under the 

 direction of T. M. Williams. After a short period of exploration 

 which showed promising results the company became involved in 

 legal difficulties that have but recently been removed, and nothing 

 was done in the interval from 1904 to 191 1. 



The ores are found along a well-marked zone which parallels the 

 talc deposits and lies on the footwall of the latter. The wall rock 

 is crystalHne limestone of the same nature as that inclosing the talc; 

 it belongs to the Grenville series, widely represented on this side 

 of the Adirondacks. The limestones are interstratified with thinly 

 bedded quartzose schists, tremolite schists and heavier hornblende 

 gneisses, and the whole series has been invaded then and there by 

 granitic intrusions. The limestones and included schists of this 

 particular district are exposed in a belt that extends from near 

 Sylvia lake, town of Fowler, on the southwest to a point a little 

 north of Edwards village, on the northeast. They represent region- 

 ally metamorphosed and compressed sedimentaries which are 



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