42 MINING INDUSTEY. 



the front of a great mountain spur, trends north 28° east, magnetic, until it 

 reaches the north part of the Yellow Jacket claim, where it makes a curve 

 amounting to an angle of 30°, trending north, magnetic, for about 500 feet; 

 then sweeping west in a sharp recurve around Gold Canon, projects northward 

 into the Alpha and Bullion. There are indicated on the map a number of 

 points where the east clay wall has been intersected, and whenever the same 

 level develops it at several places its probable course is dotted. Where this 

 is done a glance is sufficient to understand the direction of the vein. 



In general plan, this section differs considerably from the portion north 

 of it. 



From a line which traces the surface in the curves above noted descend 

 two distinct fissures, each containing an ore-bearing quartz vein, and each par- 

 taking of the geological features of the east gash or ore-channel of the north- 

 ern part of the lode. These two veins diverge at about 50°. The east fissure, 

 varying in dip from vertical to 45° east, continues indefinitely downward, show- 

 ing, in the present lowest mine-levels, a heavy quartz body with no signs of 

 immediate change ; while the west vein dips west at 45° to 48°, descending 

 to a depth varying from 300 to 500 feet, where it is cut ofi" by a nearly hori- 

 zontal seam of clay and corresponding wall of rock. After leaving the vein, 

 this sheet of clay curves eastward and down through propylite until it nearly 

 joins the selvage of clay which lines the surface of the east body. The posi- 

 tion and relation of these two veins are shown in the sections of Crown Point 

 and Yellow Jacket, Atlas-Plate 8. The section through Empire shaft on this 

 Plate marks the greatest eastward dip of the east body ; that through the 

 Crown Point shaft indicates the same body 1,600 feet further south, where it 

 has assumed a nearly vertical standing. 



Included between the two quartz veins, and bounded in depth by the cut- 

 oif clay-wall, is a continuous horse of propylite, which is divided by fissures, 

 filled with plastic clay, whose conchoidal forms terminate downward upon the 

 flat clay-wall or connect with the east vein, separating the whole interior of 

 the lode into a number of water-tight compartments. 



Deposits of silver occur in the quartz, distributing themselves capriciously 

 in segregated bonanzas, separated from each other by intervals of entirely 

 barren gangue, or of ore so poor as to be unworkable. 



