278 GEOLOGY OF THE COMSTOCK LODE. 



the east fissure of the Yellow Jacket, the west fissure here coinciding with the 

 slope of the Lode. 



The fault at the Belcher. — There is Diuch Icss cvideHce of faulting at this sec- 

 tion than on any of the preceding. The topography does not show a 

 logarithmic character; the lamination of the surface rocks is not percepti- 

 ble, nor is there much evidence of such a structure in the mine; and far 

 more of the ore was solid or composed of bunches of large interlocked quartz 

 crystals, with spaces between them, than in the Virginia mines. There is 

 some crushed quartz, however, and the character of the bonanza, which was 

 largely made up of angular fragments of country-rock, seems to indicate 

 faulting, though of a less violent and extensive character than that which 

 occurred on the flank of Mount Davidson. The bonanzas hitherto described 

 appear to have filled spaces due to secondary fracturing, while that in the 

 Belcher seems to have occupied an opening due to changes in dip, combined 

 with a relative movement of the walls, concave surfaces being brought into 

 opposition. An inspection of the section can hardly fail to produce this im- 

 pression and, if it be a foct, it furnishes another proof of the comparative 

 gentleness of the faulting action in this locality. Since the dislocating force is 

 manifestly dissipated at the ends of the Lode by distribution over a large 

 area, it is likely to grow less intense as the extremities are approached. The 

 diminution indicated at the south end of the main Lode is greater than 

 at the north end. 



Small stringers of good ore have been met on the 3,000-foot level of 

 the Belcher, the deepest level yet reached. 



cross-section through the Forman shaft. — The scctiou througli thc Baltimore and 

 Forman shafts is more valuable as a study of the succession of the rocks 

 than for any positive information it furnishes regarding the Lode. The 

 contacts in this portion of the country are much more numerous than near 

 Virginia, and one of these, seemingly continuous with the main Comstock 

 fissure, has been sufficiently opened to admit the deposition of quartz. The 

 dynamical action must have been very slight, however, for there are no 

 certain evidences, either in the shape of croppings or of lines of profound 

 decomposition, that fissures from the surface connect with this contact in 

 depth. But croppings reappear just below the Justice, and the surface and 



