ADIRONDACK MAGNETIC IRON ORES 12J 



been mined for 1600 feet on the first level 100 feet below the surface, 

 while a second level 75 feet below the first had been opened on the 

 west end. The width of the deposit according to the same 

 authority averaged 20 feet, thickening to 30 feet in places. In 1905 

 the deposit was tested by diamond drilling, the results of which 

 have shown that it is irregular and pinches in places to a thin seam. 

 Of the 12 holes put down along the strike, ore was found in all 

 but three and the maximum thickness was 22 feet which was 

 encountered near the central part of the old workings. On the 

 western end, the body apparently is broken up into several parallel 

 bands. The dip estimated from the data obtained in the drill 

 holes ranges from 45 to 65 east, being steepest on the west. 

 Several diabase dikes intersect the ore body and are said to mark 

 lines of faulting. 



The wall rock, judging from specimens collected along the sur- 

 face, is not the usual reddish granitic variety exposed in the dis- 

 trict. It has a light gray color and is made up almost entirely of 

 plagioclase, quartz and magnetite. The plagioclase belongs to the 

 basic end of the series, corresponding optically to labradorite. 

 The composition can scarcely be identified with any common type 

 of igneous rocks, but rather suggests a metamorphosed sediment. 



The ore is a mixture of magnetite with hornblende, quartz and 



pegmatite, the percentage of iron ranging within rather wide 



limits. The following analyses of crude ore (1) and concentrates 



(2) are given by Putnam as the results obtained from average 



samples: 



1 2 



Iron 34-28 66.78 



Titanium nil nil 



Phosphorus .124 .037 



From two to three tons of crude ore were required to make 

 one ton of concentrates by the methods of hydraulic separation 

 formerly used. 



The output of the mine from its opening in 1855 is reported by 

 Smock at 260,000 tons; though not specifically mentioned the 

 quantity probably represents crude ore. 



Clayburg mine. Near the site of the old forges at Clayburg 

 are two pits, the openings of which face toward the Saranac river. 

 The larger pit, on the west bank and somewhat south of the smaller 

 one located on the east side of the river, is several hundred feet long 

 and some 50 feet deep. It is partly an underground drift. The 

 strike is nearly east and west and the dip almost vertical inclining 



