74 NEW YORK STATE MUSEUM 



paper and sections prepared in 1897 and published in the Trans- 

 actions of the American Institute of Mining Engineers, volume 

 XXVII, pages 146-204, are brought up to date and are made 

 to include the results of 10 years of mining. 



There are three principal and separate faulted parts of one great 

 bed, viz: roughly from north to south, the Miller, the Old Bed or 

 Mine 23 (the first discovered under the name of the Sanford 

 pit) and the "21 "-Bonanza-Joker continuous ore body, the chief 

 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 100 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 [fig. 7-1 4]. 



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

 the truth. The ore is a steep, vertical anticline, doubled over a fold 

 of rock, and bulging at the lower part of the east limb. In No. 23, 

 which is more fully based on mining experience, a great swell has 

 developed in the eastern limb, and a tendency is shown toward a 

 closed fold, the two limbs coming almost together in depth. In 

 No. 22 the swell is more pronounced in the east limb, and a curious 

 shoulder with an almost flat top has been revealed in mining. The 

 interior core of rock shows a sympathetic development in the same 

 way. A smaller swell or bulge is manifested in the west limb. In 

 No. 21 the swell contracts a bit, 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 wellnigh 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 1 9 the upper western bulge has 



