284 GEOLOGICAL SURVEY OF THE TEEEITORIES. 



may cliange hands, while they will uot often change their names. Min- 

 ing enterprise in the region of Central City is comparatively old, and the 

 more celebrated lodes and mines are well known. Beginning with the 

 main veins of the system, striking about northeast to southwest, the 

 central portion of the rest, and afterward the outside ones will be 

 treated of. 



The Fisk lode, located on the northern slope of Bobtail Hill, was not 

 being worked at any point during my stay, so that no reliable data 

 could be obtained. It has a strike of east 37<2 north, with an. almost 

 vertical dip. Approximately parallel to it, a short distance west, run 

 the Milwaukee and Devil's Grip, two small veins. 



The Gregory lode was not worked at the time. Situated on the 

 northern slope of Gregory Hill, with a strike of east 45'^ north, it is the 

 first one that was discovered in this region. It strikes the Briggs lode 

 down in the gulch, and has been found at a depth of 250 feet, where it 

 is known as the Gregory extension, and worked. At that point it is a 

 contact-vein, having the east hanging wall of gneiss ; the western, 

 granite. By virtue of a dip of 30° to the east, it diverges from the 

 Briggs, which it strikes. It is here that the case of a slide to the east- 

 ward occurred, alluded to above, by which the vein appears of varied 

 thickness. Some disturbance has taken place here, probably occasioned 

 by slides of the ore- wall, -whereby fragments of the granite and gneiss 

 both have been thrown into the gangue-material, and are now cemented 

 together by white quartz. The ore-bearing vein is somewhat irregular 

 at the point where it was exposed — ramifying, connecting again, send- 

 ing off a number of spurs and shoots, and keeping a wavy course. Of 

 the walls, the hanging wall was well defined ; the foot wall more broken, 

 with gneissic fragments resting upon it. 



The Bates-Hunter lode begins on the northern slope of Mammoth 

 Hnl, runs through Mountain City, and is finished on Bates Hill; strike 

 east 43^' north ; dip almost vertical. I^either of the two mines on that 

 lode were in operation during May, although I am informed that the 

 Bates took up work again. The Bates is partly a contact-vein. 



Leavitt lode is located a short distance west of the Bates-Hunter, 

 having a strike of about east 40° north, and is the last large vein of that 

 northeast series. This vein is one of the best developed in the district, 

 and yields an abundant supply of ore. Yery little variation from the 

 vertical is shown in the dip, and also the course of the vein is quite 

 regular. Well-defined walls border the vein on either side, consisting 

 of granite on the north wall, gneiss on the south, to a depth of 150 

 feet, where gneiss comes in on both walls. The distance between walls 

 at a depth of 250 feet is between 4 and 5 feet, varying but little from 

 the surface down, but seeming to increase, however, with depth. 



Pyrite and chalcopyrite compose the main portion of the ore, a vein 

 of the former two feet thick being found at one place, while the latter 

 is distributed throughout the gangue-rock in small particles and masses ; 

 at times intimately associated with the pyrite, again occurring free from 

 any admixture of it. Galenite and sphalerite occur very sparingly, and 

 may not be regarded as ore. The gangue-rock is composed of quartzitic 

 and feldspathic particles, more or less' compactly agglomerated or ce- 

 mented. Sometimes large pieces of quartz will occur, thereby render- 

 ing penetration difficult for the drillers. Although the arrangement of 

 minerals between walls shows some regularity, there is no symmetry 

 about it. (Plate IV.) In this mine the following minerals were found : 

 pyrite, occuring massive and in small pentagonal dodecahedral crys- 

 tals ; chalcopyrite, massive ; sphalerite, in narrow seams, running through 



