54 MmiNG INDUSTET. 



in the last section, the lower portion of the quartz is white, and is parted from 

 the red by a seam of clay. 



Minor changes occur throughout the whole quartz-mass. They are usu- 

 ally traceable in a parallel arrangement of zones, which differ from each other 

 in size of fractured blocks, in color, in amount of clayey infiltrations, and most 

 prominently in their tenure of silver minerals. An interesting example of this 

 is in the section now before the reader. That spur which follows down the 

 east wall is charged through its eastern half with extremely rich silver sulphu- 

 rets, the argentiferous portion being defined on the west by a thin seam of 

 mixed clay, red ochre, and finely comminuted quartz. The quartz lying west 

 of this seam is redder, firmer, and far less richly mineralized of the two. 

 Upon descending, the partition line continues to separate the bodies down to 

 the west wall, where it brings up against the black (andesite) dike. Below 

 the 290-foot level the east body loses its red color. 



The west wall preserves its old dip, but has not so perfectly even a sur- 

 face. It has already begun to bend westward. The same deep explorations 

 have been continued below the termination of the vein, and there are still no 

 signs of its renewal. From the Bullion, then, to this point, the lode is an 

 immense wedge of quartz, widening as it rises toward the surface, until, on 

 the 242-foot level, it divides into three bodies, which continue to the face of 

 the hill slope, occupying respectively the west side, the middle, and the east 

 wall, and embracing two large horses of propylite. It was shown that the 

 bonanzas on the Gold Hill northern sections are confined to the east wall. 

 The evident parallelism of arrangement between them and the two last con- 

 sidered sections is an interesting instance of the unity of plan throughout the 

 lode. 



Lying to the north of the Chollar-Potosi is the Hale and Norcross claim. 

 A section through the plane of its shaft is next given. It will be noticed that 

 a marked change has taken place in this short distance. The old wedge of 

 quartz reaches down to about the same distance, but the horses have pene- 

 trated to a greater depth, cutting off entirely the middle and east quartz-spurs 

 on the lower levels. The clay wall which defined the eastern Hmit in Potosi 

 ground is still apparent on the east side of the east red quartz, but an entirely 



