320 QnCKSILVER DEPOSITS OF THE PACIFIC SLOPE, 



isrepresenteci, and pseudodiorite, pseudodiabase, plitliauites, sandstone, shale, 

 and serpentine are mingled in inextricable confusion. 



Atlas Sheet X shows a section taken along the course of the south group 

 of bonanzas. Tlie line on which the section is made is shown on the mine 

 map and was selected with a view of illustrating the continuity of ore from 

 the surface at the top of Mine Hill to the lowest workings. The group of 

 ore bodies thus intersected is for the most part distinct from that to the east 

 of the Randol shaft. It is manifest from this section that a fissure extends 

 from the lower workiiigs to the top of Mine Hill, a vertical distance of 

 about 2,000 feet, and that ore has been deposited almost continuously along 

 its entire course. This fissure is remarkably sinuous in vertical section, and 

 a long tongue of ground north of Mine Hill has manifestly moved north- 

 ward sufficiently to leave space for the deposition of ore. If one considers 

 the character of the disturbance to which the fissure must owe its origin, it 

 appears almost certain tliat this tongue of country rock overlying the fissure 

 cannot have remained intact. One would expect to find one or more fis- 

 sures intersecting it in a direction more nearl}- vertical than the south ore 

 channel, because the tenacity implied in the movement of the entire hang- 

 ing country without fracture would be improbably great, even were the rock 

 much firmer than the materials of which the Coast Ranges are chiefly com- 

 posed. Such a fissure intersecting tlie hanging country really exists, and a 

 trace of it may be perceived on this section from the l,oOO-foot level down- 

 ward, where the stopes show that the ore occurs on parallel lines. The 

 line of the northerly stopes in this region if continued upward would reacli 

 the surface near the point at which the Randol shaft appears projected. 



On Atlas Sheet XI two sections are shown, cutting the northern portion 

 of the mine on parallel north and south planes. One of them is taken 

 through the Randol shaft and the other ooO feet west of it. The two are 

 to be considered together and as if they were superimposed. The western 

 section shows the same group of bodies as is (Jepicted upon Sheet X, but 

 cut at a different angle. The relations of the section on Sheet XI are most 

 easily appreciated by reference to their traces on the mine map (Sheet IX). 

 The eastern section, through the shaft, on Sheet XI is very different. It 

 shows only the edge of the south ore channel, or of that series of deposits 



