270 NEW YORK STATE MUSEUM 



and pitches northward under it ; it is opened as a pit and under- 

 ground drift for a distance of 500 feet on the strike. It measures 

 20 to 50 feet in width from wall to wall, but includes bands of lean 

 or barren gneiss intercalated with the magnetite. An interesting 

 feature of its geology is the presence of massive granite on the 

 eastern or hanging side (the dip is about 75° E.) whereas the foot 

 wall consists of the usual hornblende gneiss. The granite on the 

 north end also caps the ore body. 



The California mines are about 7000 feet farther north, on the 

 opposite side of the ridge on which the Sterling and Lake deposits 

 outcrop, and about one-half of a mile distant from these. They are 

 based on a thin but persistent band of magnetite that lies nearly flat 

 and outcrops on the southern and southwestern sides of the hill. 

 The ore is of Bessemer grade, whereas the Lake and Crawford 

 mines contain too much phosphorus to come in that class. 



The Sterling and Lake mines, of which the latter is now the only 

 active producer on the property, are opened on two long lenses or 

 shoots which outcrop on the side hill at the foot of the lake and 

 extend north under the latter at an angle of 28° for the Sterling 

 and 23° for the* Lake body, measured on the average inclination of 

 the respective slopes. Both dip to the east, although rolls occur 

 which locally reverse the normal dip. The Sterling mine is down 

 1000 feet and has not been worked since 1902. The Lake slope is 

 over 3200 feet in depth. The two slopes are 500 feet apart at the 

 surface and pursue a slightly divergent course. From the presence 

 of numerous pinches and minor rolls in the Lake mine, it might be 

 reasonably maintained that the two bodies are parts of one original 

 deposit which has been squeezed out into the present form. It seems 

 to be the prevalent opinion locally, however, that they are separate 

 and distinct deposits and the Lake, if it were continued on the dip, 

 would lie above the Sterling deposit. For a distance of 2300 feet 

 on the slope, granite forms the hanging wall of the Lake slope, but 

 at that depth gives way to hornblende gneiss. The Lake mine has 

 yielded 1,500,000 tons of shipping ore up to the present time. The 

 ore runs about 57 or 58 per cent iron and i per cent or so of phos- 

 phorus. 



To the east of Sterling lake about 3000 feet are a series of lenses 

 that lie along a nearly north-south axis, on w^hich are located the 

 Causeway, Mountain and Smith mines. About 800 feet farther east 

 a second series, with openings known as the Augusta, Cook, Scott, 

 Oregon and Long mines, occurs along a parallel axis measuring 



