EKDLicii.l GEOLOGY GAEDNER AND ILLINOIS LODES. 289 



is 3J to 4 feet. The minerals of this mine do not vary from those of the 

 others, either in relative quantity or mode of occurrence. 



South of the Monte Cristo are the Gardner and Illinois, of a little 

 more northerly strike, neither of which was worked during my stay. 

 The distribution of the precious metals seems to vary constantly, and 

 thus far science has not been able to produce a guide whereby mistakes 

 can be avoided in the appreciation of the relative or absolute value of 

 ore from lodes contiguous to those yielding good profits. In no branch, 

 perhaps, is a want of this kind so keenly felt as in mining, where experi- 

 ence must always be bought at a high price. Upon a large number of 

 lodes in the district at present under consideration, large sums of money 

 have been expended, but the owners or workers were obliged to aban- 

 don them — temporarily, it may be hoped — for some i)ursuit more re- 

 munerative. The Alps lode, to the southwest of the Illinois, is reported 

 as having been doing very well some years since. 



Besides the mines that have been enumerated here, quite a number of 

 small ones are in operation, only presenting features that would essen- 

 tially repeat those given above, or possessing no further interest. On 

 the other hand, a considerable percentage of the more important 

 mines were closed during the short time of my stay, i)artly on account 

 of the inability of owners to resume work, partly on account of the 

 spring-waters filling the levels and shafts, so that the facts given of the 

 gold-mines of this section, taken as a vv hole, must necessarily be incom- 

 plete. 



There yet remain to be treated of, five lodes belonging to this region, 

 located on the outer edge of what might be termed the lode-circle. 



The Forks lode, situated on Quartz Hill, in the immediate neighbor- 

 hood of the California, Mercer,^and Flack, has a strike of east 10° north. 

 Gneissic granite composes the wails on either side, which are smooth 

 and well defined, the hanging one dipi>ing about 25° to the south. At 

 present the working-shaft is 250 feet distant from the discovery-shaft, 

 located on the line of intersection of the Helos with the Forks, on which 

 it remains down through its entire depth of 517 feet. Keeping on reg- 

 ularly in its course, the Forks shows very little deviation either in direc- 

 tion or in thickness of vein between walls ; the thickness is about 5 feet. 



Both the Forks and Helos are galena veins, and have as such afforded 

 already a large quantity of that mineral, but the main reliance for re- 

 muneration is upon the silver contained therein. To some extent only 

 has the Helos been worked, as the Forks showed a larger body of ore. 



Of minerals, mainly galenite and sphalerite are found, mixed with small 

 amounts of pyrite on chalcopyrite. Galenite occurs, from the very fine- 

 grained feathery variety to the coarse-grained breaking in cubical 

 fragments. Argentite is contained between the single crystals of the 

 latter. Of a similar character is the J. P. Yv hitney, although scarcely 

 developed sufficiently to admit of any opinion. This also is a galena- 

 vein, showing at a depth of 50 feet a body of galena 12 inches in thick- 

 ness, with other portions of the same mineral at either side of the walls. 

 (Plate IV.) Pyrite and chalcopyrite occur as ores, and yield a small 

 amount of gold ; but silver is the main object for mining here ; strike is 

 east 12° south. Besides galenite, sphalerite, pyrite, and chalcopyrite, 

 we find small quantities of argentite and cerussite. 



The Dallas lode is located on the eastern slope of the hill immediately 

 north of Black Hawk. It has been worked quite extensively, and the 

 vein can be traced along for nearly 1,000 feet. Contrary to the usual 

 course, it strikes a little south of east ; the exact number of degrees could 

 not be determined by the compass on account of strong local attraction. 

 19 G s 



