Io8 NEW YORK STATE MUSEUM 



source of the ore. There are several shafts for Old Bed and " 21 '' 

 (named from the lot) and there are large open pits as well. The 

 axis of the fold strikes about n. 30° e. true, and, as stated, pitches 

 south. The full extent to the south has not yet been revealed. 

 The sections here used are 24 in number, separated by intervals 

 of ICO feet, so that they cover 2300 feet. The folded bed is broken 

 by two main faults with strike a little more northerly than the 

 axis of the fold, and apparently by one east and west fault under 

 the skip way of mine " 21." At least two trap dikes are known, 

 running parallel with the main faults and probably themselves 

 following additional small fault lines, while one other dike crosses 

 the Joker at its southerly end in a nearly east and west direction. 

 In the Harmony mines, the apparent prolongations of the north 

 and south dikes are revealed. If now the reader follows the 

 description with the diagrams beginning on the south with No. 24, 

 the relationships can be most intelligibly stated [figs. 20-27]. 



Section 24 is largely inferential, but it is probably not far from 

 the truth. ' The ore is a steep, vertical anticline, of which we know 

 little except at the crest. In No. 23, which is more fully based on 

 mining experience, a swell has developed in the eastern limb, and 

 the two limbs have come together in depth. The drill has revealed 

 a second and lower bed. In No. 22 the swell is still pro- 

 nounced in the east limb, and a curious shoulder with an 

 almost flat top has been revealed in mining. The lower bed 

 continues as in the last section. In No. 21 the swell contracts* 

 somewhat, but the bulge toward the upper left-hand begins 

 to assert itself, which is thereafter sO' marked a feature, and is 

 apparently due to the stretching of a Avellnigh viscous mass 

 under irresistible compression, if indeed the rock was not still 

 liquid from an original molten state. In No. 20 this upper left- 

 hand bulge is much more pronounced, while the eastern shoulder is 

 still very much in evidence. The intervening horse of rock has 

 widened appreciably. In section 19 the upper western bulge has 

 thinned somewhat, and has a very flat top, while the eastern 

 shoulder has narrowed. It is very near the point where the Joker 

 shaft first grounded in the ore. In No. 18 the upper western bulge 

 has shrunk still more and the lower eastern shoulder has almost 

 disappeared. Deeper mining has shown the true relations lower 

 down on the limbs. We find them pinched together, so as to 

 entirely circumscribe the horse of rock. In No. 18 also the 

 sections first intersect the Miller pit as a small end of what soon 



