476 GEOLOGY AND MINING INDUSTRY OF LEADVILLE. 



The first level from No. 3 shaft, at 100 feet below the surface, starts 

 in the White Porphyry below the upper ore horizon, which pitches at 20 

 to 25 towards the Amie line. Drifts were run to the north and west and 

 to the southwest on this level ; the former passes at 20 feet from the shaft 

 into the upper ore horizon, whose lower portion consists of soft red silicious 

 iron, passing into soft black iron or into chert; turning westward it reaches 

 the continuation of the sand carbonate ore body of the Amie, from which 

 considerable rich ore was taken. The southwest drift runs mostly in the 

 underlying porphyry, in which are several thin streaks of ore and of Chinese 

 talc. To the west of this drift, near the Amie line, are old stopes, from 

 which a peculiar white sand ore, lying at the top of the ore horizon, was taken. 

 This ore is said to resemble a decomposed porphyry so much that at first 

 it was supposed to be worthless, but on examination was proved to be 

 extremely rich, assaying as high as 1,600 ounces of silver and giving mill 

 runs of 300 ounces, but containing little or no lead. It is probably the 

 result of a leaching of the original ore body, during or subsequent to the 

 process of erosion. 



No. 5 shaft was sunk later and passed through 125 feet of Wash, 5 

 feet of iron, and 110 feet of White Porphyry, stopping in the Parting 

 Quartzite and White Limestone, which here dip gently northward. A drift 

 to the northwest, on the 383-foot level, from this shaft, and a western branch 

 from this drift in the direction of No. 3 shaft find a small body of iron in 

 the porphyry, which may correspond to the second ore horizon of the Amie 

 mine. A drift to the northward, on the other hand, finds quartzite in the 

 midst of the porphyry, which is supposed to be a detached portion of the 

 Parting Quartzite, as shown in Section G. 



The northern workings are opened by No. 1 and No. 2' shafts, and also 

 connect with the northern Contract shaft. The workings from the latter 

 have developed little of importance ; the shaft was sunk through 85 feet 

 of Wash and 30 feet of iron vein material. Drifts to the south and west 

 rise to the overlying Wash at their extremities, but develop no ore bodies. 

 To the north the workings follow some thin streaks of pay ore standing 

 nearly vertically in the iron vein material. 



'The number of this shaft has been omitted on the map ; it lies near the Dunkin line, abont one 

 hundred feet southwest of No. 1. 



