296 GEOLOGICAL SURVEY OF THE TERRITORIES. 



occurring iu small particles as well as iu larger pieces, and they were 

 probably derived from the surrounding rock. 



As yet no very great progress has been made in the development of 

 this mine. A shaft of 85 feet has been sunk, and several short levels 

 started in both at the bottom and before reaching it. The large percent- 

 age of silver contained in the ore renders it advisable to follow almost 

 every spur, which can readily be done in the soft gangue-rock, so that, 

 although but little headway is made in the working of the vein, it yields 

 large profits. At the western estension of the Colorado Central, a nar- 

 row dike of porphyritic obsidian crosses the vein at right angles, with- 

 out, however, occasioning any dislocation. 



Constituting the ore, the following minerals are found : galenite and* 

 sphalerite, containing an appreciable percentage of silver ; antimonial 

 fahlerz, stephanite, argentite, and pyrargyrite ; the latter two intimately 

 associated with the galenite, the fahlerz occurring in masses of 

 more than several pounds in weight. ISTone of these minerals are crys- 

 tallized, however, but occur massive. Galenite is found from the very 

 fine-grained variety, passing through every phase, to the coarse-grained, 

 breaking in large cubical fracture. 



On the same hill, within a short distance eastward of the Colorado 

 Central, is the Saco, in which operations had been taken up again but a 

 short time previous to my visit. It strikes almost due east and west. 

 A tunnel of 320 feet leads to the vein, the main ore of which is sphale- 

 rite with galenite. As at the Colorado Central, the south wall had 

 not been found, allowing a very considerable width for the fissure. 



The Star mine is close by, striking parallel with the Colorado Cen- 

 tral with an almost vertical dip. At the time, the body of ore was 

 small, mainly on the south side of the lode. 



The Equator lode was not worked during my stay; it has a strike 

 of approximately northeast to southwest ; formerly it was worked, and 

 yielded good pay. 



On the hill opposite Mount Leavenworth, to the south, quite a num- 

 ber of small lodes have been found and temporarily worked, rarely 

 yielding sufficient pay, however, to warrant a continuation of opera- 

 tions. They seem to be local infusions of ore between the strata of 

 gneiss. 



To the northwest of Georgetown, on Mount Sherman, a number of 

 remunerative lodes are located, undergoing active working. One of the 

 largest and richest there is the Pelican lode. As far as could be deter- 

 mined, considerable local attraction interfering, the strike of the Pelican 

 is about north 16<^ east, with a vertical dip. The vein is from 4 to 10 

 feet between walls, widening somewhat the deeper it goes. Another 

 lode, the Elkhorn, has a strike of north 35° east, dipping on an average 

 20° to the north. This Elkhorn approaches the Pelican both on a hori- 

 zontal and vertical projection, and while in the third level it is yet 30 

 feet distant from it, 80 feet deeper they have joined ; the Pelican keep- 

 ing its true course and dip, while the Elkhorn accommodates itself to 

 it. Between these two lodes, the intervening rock is gneissic, the same 

 forming the entire south wall of the Pelican. Although there is a 

 semblance of a wall on the north side, its character could not be deter- 

 mined : but, judging from surface-outcrops, it seems to be partly gra- 

 nitic, partly gneissic. A dike of porphyry is said to cross the vein iu 

 one of the lower levels. Blende and galenite mainly constitute the ore, 

 mixed with small quantities of pyrite, chalcopyrite, argentite, fahlerz, and 

 pyrargyrite. At the point where our section was taken, (Plate VI,) in the 

 lowest east level, the vein was 6 feet thick, containing almost in the 



