THE MINING AND QUARRY INDUSTRY 1915 83 



The blende and .pyrite are segregated, instead of being intergrown 

 as in most instances, while they are accompanied by secondary 

 calcite and other unusual features. 



J. C. Finch reports to the writer the occurrence of zinc on the 

 west branch of the Oswegatchie, near the falls, about 3 miles above 

 FuUerville. This locality is rather remote from the main district 

 and indicates the extension of the limestone farther south than has 

 been indicated on the maps. It appears quite certain that a narrow 

 tongue of the limestone extends south on the east side of the West 

 Branch at least to the locality named, which is just off the limits of 

 the Gouverneur quadrangle. 



The Davis farm, northwest of Pleasant Valley school, is one of 

 the new localities for blende that has been under prospect. It is 

 held under lease by Gouverneur parties, with B. J. Hatmaker in 

 charge. The ore occurs in disseminated grains within a zone of 

 impure limestone, but had not been explored to any extent at the 

 time of the writer's visit in August 1916. 



Across the Oswegatchie river from the mine of the Uniform 

 Fibrous Talc Co. is a ridge of impure Hmestone in which an old 

 talc shaft was sunk years ago. Nearby an opening shows 3 to 4 

 feet of fairly rich blende, with some pyrite, having a mottled ap- 

 pearance from inclusions of carbonates. The ore appears to run 

 about north and south and dip steeply to the west, but it has not 

 been explored sufficiently to reveal fully the extent and attitude of 

 the body. Another outcrop is found on the south side of the ridge, 

 nearly in line with the first. The locality is on the Freeman farm 

 now leased by the Dominion Company. 



Nature of ore occurrence. Two types of ore bodies may be dis- 

 tinguished on the basis of the methods of aggregation. In the one 

 type the zinc and iron sulphides form a well-defined band, shoot or 

 lens within the limestone. The contact is sharp and shows little evi- 

 dence of a true gradation between the ore and wall rock, although 

 if the two are frozen the ore may send out stringers from the main 

 body for a little distance into the limestone. In this type, however, 

 it is rare to find both foot and hanging wall tightly cemented ; more 

 often the ore breaks clean from one wall and is separated from the 

 limestone by a gouge of talcose decomposition products. This 

 type of deposit averages high in metallic content, the blende and 

 pyrite together forming more than 50 per cent of the mass, and 

 specimens may be found that are practically solid sulphides. The 

 visible gangue minerals are chiefly serpentine and talc which occur 



