MINES OF BEACON HILL. 
357 
occurring in fractured phonolite, sometimes shows considerable pvrite, in small 
pyritohedrons lining the little vugs and fissures, and often accompanied by sphal¬ 
erite. 
PAY SHOOTS AND LODE STRUCTURE. 
The principal pay shoot in both mines is that of the C. K. & N. lode, which 
has already been partly described in connection with the El Paso mine. The 
lode is a narrow sheeted zone cutting through granite and phonolite, the ore occur¬ 
ring in both rocks, though it is usually wider in the granite. The fractures are 
partly open, particularly the principal fissure of the zone, and show no gouge or 
slickensiding. The main fissure is rarely more than 4 inches wide. It is some¬ 
times solidly filled with quartz and calaverite, but more often shows an open 
vuggy structure, the calaverite occurring both as implanted crystals in the vugs 
and within the quartz lining the walls of the fissure. Occasionally the main fissure 
contains nearly loose slabs of country rock, a few inches in thickness, coated on 
all sides by crystals of quartz and fluorite. Calaverite occurs also in the smaller 
less regular fractures on each side of the main fissure, as is indicated by the fact 
that the screenings from a width of 3 or 4 feet are usually of high grade. Accord¬ 
ing to Supt. E. G. Taylor, the calaverite (or some other gold telluride) sometimes 
occurs alongside the principal fissure in granite that is not perceptibly fractured. 
Such granitic ore is grayish or greenish in color and somewhat porous, showing 
metasomatic alteration, whereas the unaltered granite is reddish in color and 
dense in texture. This pay shoot has been stoped from the El Paso line into the 
Old Gold ground and from the 370-foot level to within 165 feet of the surface. No 
ore is known above this, though the lode is said to have been followed for about 30 
feet above the point where the ore ended. Toward the west the pay shoot con¬ 
tinues to the Old Gold phonolite sill. In the phonolite the lode splits into a few 
small, irregular fissures and is soon lost. The ore does not extend into the phonolite 
and has been found to fall rather below the average grade as the sill is approached. 
On level 3 of the C. K. & N. no stoping had been done at the time of visit in January, 
1904, and it was a little doubtful whether the C. K. & N. lode had been found. 
The fissure followed in the drift was very indistinct, showing only a little pyritic 
mineralization in granite alongside a small phonolite dike. No calaverite and 
nothing resembling the open, vuggy C. K. & N. lode as known above were seen on 
this level. 
The Old Gold pay shoot was first encountered on level 1 of the Old Gold as a 
small, rather irregular, vuggy fissure in the phonolite sill, accompanied by some 
irregular fracturing. The best ore occurs in the main fissure, but the irregular 
fractured phonolite is also ore to a maximum width of 10 feet. As this ore proved 
to be of high grade and showed such a width on this level, chutes were put in and 
the drift timbered preparatory to carrying up an extensive stope. It was soon 
found, however, that the ore extended only 15 feet above the level, being limited 
to the phonolite. Later developments on the level below have shown also that 
this pay shoot does not extend below the bottom of the phonolite. 
