THE MINING AND QUARRY INDUSTRY 97 



equally probable that the narrowing- may be only a temporary fea- 

 ture, inasmuch as the deposits are inclined to be lenticular. 



The mine possesses some unique features from a geologic stand- 

 point. Three parallel ore bodies occur known as the black vein, 

 the blue vein and the gray vein, with a maximum distance 

 between the adjoining walls of each of 40 feet. The dip is 70° 

 at the surface flattening to 55° at 325 feet. Smock states that the 

 deposits have a marked shoot structure and pitch at an angle of 40°. 

 The first ore body encountered on the foot wall is the gray vein 

 which is from 3 to 25 feet thick. It yields a granular mixture of 

 magnetite and gangue minerals, chiefly quartz and feldspar. The 

 gangue is stained by iron, and when observed in hand specimens the 

 ore has a mottled gray appearance. In the black vein the ore is a 

 fine, somewhat friable magnetite, carrying rounded grains of apa- 

 tite and resembles the product of the Nelson Bush mine. In con- 

 trast with the other two the blue vein affords martite, a form of 

 hematite pseudomorphous after magnetite. It has a granular to 

 massive texture, steel-blue color and reddish streak. It is seamed 

 more or less with jasper and calcite, but is a rich ore. The conver- 

 sion of magnetite into hematite, which has evidently taken place 

 here, offers no difflculties of explanation, though it may be said that 

 it is not a common occurrence in Adirondack deposits. It is less 

 apparent, however, why the ore body on the hanging wall should 

 have been affected, while the others under apparently similar sur- 

 roundings have largely escaped the change. 



The Arnold mine has been opened for a distance of about 700 

 feet along the strike. There are two slopes, 500 feet apart, driven 

 on the dip of the gray vein. Cross cuts connect the levels on this 

 vein with the overlying black and blue veins which were exploited 

 in conjunction with the former. 



At the south end the Wells, Finch and Indian mines have not 

 been in operation for many years. The pits are filled with water 

 and debris, and little information can be obtained as to the extent 

 of the ore. There are evidently several parallel deposits of the 

 same general character as those already described. 



The present capacity of the mines when under full operation is 

 about 240 tons a day. Compressed air supplied from the large 

 compressor plant at Arnold station is used in operating the hoists 

 as well as in the underground work. The ore is loaded into cars 

 and conveyed over an incline to the separator, at the station, the 

 cars being run in balance. 



