142 NEW YORK STATE MUSEUM 



unclouded plagioclase. The biotite is closely involved with the 

 particles of ore. A partial analysis of the so called " ore " by 

 W. F. Hillebrand gave the following: 



FeO 21.34 Ti02 10.55 V2O5 .34 S .10 



Fe203 11-52 Cr203 .25 P2O5 .46 Fe 24.65 



The specific gravity was 3.199. The above percentages corre- 

 spond to 



Ilmenite 25 . 344 



Magnetite 16. 704 



Remaining FeO 6.912 



The association with biotite is unusual for the Adirondacks but 

 has been noted in-Brazil by O. A. Derby [Am. Jour. Sci. Apr. 1891. 



P- 31 i]- 



Two hundred yards northwest is another pit 15 by 30 feet and 10 

 feet deep. The walls are gneissoid gabbro and the ore resembles 

 the usual run of the gabbro ores. No analysis has been made, but 

 the specific gravity of 3.964 indicates more iron than the sample 

 from the first pit. 



At the extreme summit of the mountain which stands at 1640 

 feet a mass of ore outcrops, larger than the bodies at the foot, and 

 indicating from its position a, character of exceptional resistance to 

 erosion and weathering. An open cut has been excavated 40 feet 

 long, 10 feet wide, and apparently 40 or 50 feet deep. It is now 

 filled with water and its depth is estimated by the size of the neigh- 

 boring dump. The cut runs north and south and is parallel with 

 the vertical foliation of the walls. Lean ore and gabbro (or strictly 

 speaking norite) outcrop 10 or 15 yards to the west across the 

 strike and gradually pass into the usual massive rock. Some 200 

 feet vertically below the summit and south of it, in the side of one 

 of the characteristic cross gulches of the mountains an adit has 

 been run with the intention of striking the ore in depth. It must 

 be 100 to 150 feet long, and while it seems not to have cut the ore, 

 it has yielded beautifully fresh samples of the country rock, besides 

 giving the name to the mountain. When examined in thin section, 

 the rock proves to be a true, gneissoid norite, hypersthene being 

 the most prominent bisilicate present. 



It is thus analogous to the basic rocks of Norway which contain 

 titaniferous magnetite in that country. Green augite, brown horn- 

 blende, plagioclase and garnet are the other components. In the 

 ore, the microscope reveals besides the iron minerals, brown horn- 

 blende, serpentinized olivine, garnet and colorless transparent labra- 



