524 GEOLOGY AND MINING INDUSTRY OF LEADVILLE. 



Archean formation. Its horizontal distance from the Moose mine is about 

 two miles. The expense per foot of driving such a tunnel after the first few 

 hundred feet, as any person familiar with mining can readily see, must be 

 very great. The only ore bodies which it can strike will be those occur- 

 ring at considerable depths in the Archean rocks. In this extent of two 

 miles a valuable ore body might be struck, especially near some dike of 

 eruptive rock, but the probabilities are against it. As far as present devel- 

 opments show, the veins discovered in the Archean in this region are gen- 

 erally small and of no great value. Even in the case of a well-defined 

 vertical fissure, the advisability of running so long a tunnel to strike it in 

 depth, unless it had been proved by actual exploration to be rich at the 

 depth at which it would be reached by the tunnel, would be extremely 

 doubtful. 



BUCKSKIN CANON. 



The neighborhood of Buckskin Cafion is a region of important devel- 

 opments of ore bodies, which are not confined to the horizon of the Blue 

 Limestone, but occur also at lower horizons, some small bodies having even 

 been discovered in the Archean rocks. The most important of these is the 

 Phillips mine, which was discovered in 1860 by Joseph Higginbotham, 

 commonly known as ''Buckskin Joe," from whom the neighboring town 

 received its name. The ore occurs in the Lower Quartzite, near the bottom 

 of the valley, on the south side of the stream. Here an immense lenticular 

 body of iron pyrites, with a little copper pyrites and a gangue of sulphate 

 of baryta, follows the strike of the rocks up the gentle slope of the valley, 

 rising from the stream bed to the foot of the caflon walls. Erosion having 

 laid bare this body in a length of about two thousand feet, it was mined by 

 the early settlers in an open trench from 20 to 30 feet wide and about fifteen 

 to twenty feet deep. Being exceptionally exposed to the action of water 

 and of the atmosphere, the upper part of the deposit was entirely oxidized. 

 By a natural process of concentration this oxidized portion became very 

 rich, so that in the early days, even with the rude processes then in use, 

 consisting mainly in sluicing and grinding in arastras, it was worked at a 

 profit, and from a quarter to a half million dollars are said to have been 



