bansome.] LODES OF UNCOMPAHGKE CANYON. 199 
carry conspicuous lodes, have cut the San Juan breccia into huge, 
nearly vertical slabs (PI. VII), which, becoming undermined at their 
bases, occasionally fall in chaotic ruins at the base of the cliff. A 
second and less prominent set of fissures, usually carrying quartz 
stringers, lias a general strike of about N. 60° W. The relative ages 
of the two sets of fissures could not be determined. 
Silvi r Queen mine. — This is a small mine nearly a mile north of 
the Silver Link, in the canyon of Bear Creek, and on the northern 
boundary of the quadrangle. The lode, which is possibly a continu- 
ation of the Silver Link, here strikes N. 3° E., and is practically ver- 
tical. It is a breccia zone, 10 or 12 feet wide, in San Juan breccia, 
with a clay gouge on the east wall. The pay streak, from 3 to 6 
feet wide, lies next the clay seam on the east wall. It is worked 
through a tunnel 300 feet in length and a 40-foot shaft with short 
drifts below the tunnel level. 
As far as known, the ore occurs in three distinct bodies or shoots, 
pitching south. In such shoots there is practically no quartz, the 
ore, sometimes with a little barite, filling the spaces between the 
fragments of country rock, which is altered to a soft, putty-like 
material, locally called "talc," but in reality impure kaolin. The 
northern ore shoot, nearest the tunnel mouth, consists of low-grade 
copper ore, chiefly chalcopyrite, with subordinate galena and tetra- 
hedrite. It is separated from the next ore shoot on the south by 
12 or 15 feet of solid quartz, carrying too little ore to work. This 
second ore body was rich in a bism uthif erous silver ore (argentif- 
erous sulphobismuthite of lead), associated with galena, at the tun- 
nel level, but changed into chalcopyrite in stoping upward. The 
third ore body, also separated from the second by a mass of rela- 
tively barren quartz, is almost wholly galena ore. South of this ore 
body tin; main lode is cut, but not noticeably faulted, by a younger, 
nearly east-and-west vein, carrying galena, chalcopyrite, and zinc 
blende and assaying fairly well in gold. South of this intersecting 
vein the main lode is poor and grows smaller. It is to be noted that 
not sufficient work has been done to establish the fact that the three 
small ore bodies cut in the tunnel are really distinct and character- 
ized throughout by different kinds of ore. The fact that the second 
one changed into chalcopyrite when followed upward would rather 
tend to negative this idea of the characteristic individuality of these 
ore bodies. 
Post-mineral movement is indicated b}^ the clay gouge along the 
east wall of the vein and by similar sheets of gouge within the vein, 
generally nearly parallel to the walls. Contrary to the experience on 
the Silver Link, the best ore is said to occur in soft clayey ground. 
The mine was working a small force in 1899, the ore being packed 
to the toll road on burros and thence hauled to Ouray in wagons. 
In 1900 it was idle. The total output has been between $15,000 and 
820,000. 
