MINES OF BEACON HILL. 
361 
Gold Dollar lodes the ore goes deeper, but even in these lodes little ore has been 
found below 350 feet in depth. The pay shoots occur irregularly in the lodes and 
are not, so far as observed, related to cross fissures or intersections. 
The main ore body of the Prince Albert occurs at the intersection of the Prince 
Albert lode with an intrusive sheet of phonolite. This sheet is about 8 feet thick 
and dips north-northeast at an angle of 30°. It is clearly an offshoot from the 
main phonolite mass of Beacon Hill. The ore body, most of which has been stoped 
out, was about 200 feet long and had a maximum width of 40 feet. The general 
relation of the ore to the Prince Albert fissure zone and to the phonolite sill is shown 
in fig. 15 (p. 208). It extended from the surface southwest of the Prince Albert shaft 
down to level 1 of the Gold Dollar mine and is said to have produced over 10,000 
tons of good ore. This ore occurred entirely in the granite, the fissures being prac¬ 
tically barren within the phonolite. A little low-grade ore only has been found in 
the granite on the under side of the phonolite sheet. From a maximum width of 
40 feet, where it rested upon the phonolite, the ore seems to have contracted rather 
abruptly 20 or 25 feet above the phonolite to the narrow width of the Prince Albert 
lode proper, which carried ore up to the surface. 
In the Beacon claim a little ore has been obtained from fissures in the main 
phonolite intrusion. This however, is exceptional, the bulk of the Beacon Hill ore 
occurring in the granite. 
UNDERGROUND WATER. 
These mines were formerly much hampered by water, even at a depth of 200 
feet. The levels were drained by the Standard tunnel and now by the El Paso tun¬ 
nel, though at the time of visit there was stagnant water in the sump of the Mabel 
M. shaft. 
