Model of an Arizona Gold Mine 5 



This mine is on a large ore chute. After the vein 

 had been found, the prospector explored it along its 

 length until he found a place where it was unusually 

 rich. This was the outcrop of a chute. As the mine 

 grows deeper the bottom of the shaft, while still in 

 the vein, will leave the ore body. The working faces 

 of this mine at these deeper levels will be off to the 

 left and will be connected to the shaft by a long 

 gallery. 



In the upper part of the vein, called the OXID- 

 IZED ZONE on account of the nature of the minerals 

 contained in it, the distribution of the gold is much 

 more irregular than it is in the SULPHIDE ZONE 

 below. In the oxidized zone the ore in the main ore 

 chute is again segregated into minor chutes. Three 

 of these are plainly shown by the worked-out areas 

 pitching do^\^lward and to the left which appear in the 

 upper part of the model. 



Entrance to the mine is through the SHAFT 

 which appears at the left. This is a vertical shaft. 

 To suit other conditions, shafts in many mines are 

 inclined. Such shafts are sometimes called INCLINES. 

 In still other mines it has been found better to run a 

 nearly horizontal gallery into a hillside. This, which 

 is practically a shaft laid on its side, is a TUNNEL. 

 The shaft in the model is divided into two COMPART- 

 MENTS and is hence a two-compartment shaft. To 

 the right is the HOISTING COMPARTMENT through 

 which the ore is raised and through which entrance 

 and exit are ordinarily made. The smaller compart- 

 ment to the left is the LADDER-WAY. In this are 

 placed the various pipes and electric wires which enter 

 the mines, as well as ladders for emergency use. In this 

 mine the ladders are continuous. This is unusual. In 

 most mines the ladder-way is interrupted every thirty 

 feet or so by a platform to minimize the danger of falls. 



[5] 



