385 
MINES OF BULL HILL. 
shown, but it is in several places cut and crossed by the basalt. It is seen on all 
levels but the first. 
A second latite-phonolite dike 4 to 5 feet wide and practically parallel with the 
first is seen just south of the shaft on levels 2, 3, and 4. 
Two hundred feet south of the shaft, on the 250-foot level, ore occurs in the 
larger basalt dike and for a foot or two on each side in the country rock. The values 
consisted of tellurides distributed in small seams and fractures. The rock was 
screened and the screenings, which formed a small proportion of the whole, shipped 
at $60 per ton. The stope at this place is 25 feet long, 15 feet wide, and about 45 
feet high. 
On the 350-foot level 150 feet south-southeast of the shaft a small pocket of 
similar ore occurred on the large dike, and a stope was carried 20 feet below the 
level 8 feet wide and 15 feet long. On the 450-foot level stoping above the level 
was in progress at the time of visit. The values here extend for a short distance 
out into the breccia. 
No ore shoot of importance or persistence has been found on this dike. The 
ore occurs in bunches or pockets, at the edges of which the values decrease in all 
directions. No conditions influencing the concentration of gold-bearing minerals 
at these places were observed. 
On the 250-foot level the workings explore the intersection of the two basalt 
dikes and the fault by which the larger one dislocates the smaller. On the west 
side of the fault plane a body of ore occurred along the small dike, which is here 
considerably decomposed. The ore carried both tellurides and free gold derived 
from them by oxidation. Although the sorted ore averaged 4 to 5 ounces, the 
valuable minerals were so disseminated that they could only rarely be seen. The 
stope is 35 feet long, 5 feet wide, and extends 20 feet above and 20 feet below the 
level. It yielded $4,000. 
On level 2 another body of ore was encountered northeast of the main shaft. 
The values, mainly tellurides, occurred in the seams of the “basalt,” and particularly 
near the latite-phonolite dike. The screenings were ore, and averaged about 20 per 
cent of the total rock broken in the stope. Their value was about $60 per ton. 
The stope is 150 feet long, 5 to 6 feet wide, and extends from 40 feet above 
level 2 down to level 3, a total of 150 feet. Below level 3 the grade of ore was 
too low to be profitably mined. 
On the bottom level a 250-foot drift on the small dike under the stope above 
encounters only $10 ore and no stoping has been done. 
The latite-phonolite dike just south of the shaft has been drifted to the south¬ 
west, on level 2, and though some fair assays were obtained, no ore was found. 
On level 3 the dike is not prospected, but on level 4 it contains ore and drifting 
had just commenced at the time the mine was visited. The contact at each side 
is sharp and distinctly marked by a narrow veinlet. Small druses partially filled 
with comb quartz carry tellurides, which also occur in the seams of the dike. The 
surrounding breccia contains finely disseminated pyrite, but, except within an inch 
or two of the dike, does not carry values of importance. 
