288 QUICKSILVER DEPOSITS OF THE PACIFIC SLOPE. 



minerals. Were this a case of local chemical action, one would expect to 

 find similar inst^mces in othei- parts of this mine and in the other quick- 

 silver mines of the slope, but, excepting at Sulphur Bank and at Steamboat 

 Springs, no such temperature has been observed elsewhere. It is clear that 

 this unusual temperature, together with the nature of the occurrence of the 

 sulphur, points to the deposition of the ore from volcanic emanations and at 

 a comparatively very recent period. 



structure Tlic uppcr portion of the mine formed an immense ore body, 



or, more strictly, a confused group of ore bodies, each irregular in shape 

 and divided from the rest by thin layers of poor or barren rock. The 

 lower portion of this great ore body passed over into two parallel veins 

 dipping at a high angle. These veins carried considerable quantities of ore, 

 which did not indeed extend continuously along the fissures, but occurred 

 in lenticular masses at the fissures. The veins also often showed thin 

 seams of ore where there was no sufficient accumulation to permit of stop- 

 ing. Slickensides and clays were abundant along the veins. They carried 

 ore as far as explored, to the 600-foot level, but at that depth no valuable 

 body of ore was found. The relations of the upper mass to the veins led 

 me to believe that a third fissure must exist in the foot-wall, and at my 

 suggestion a drift was run in to the position which the structure seemed to 

 indicate as the probable position of such a third vein. A fissure was found, 

 but at the point where it was struck it carried only pyrite. The ground 

 was very hopeful in appearance, but the aflPairs of the mine were suffering 

 greatly from the depression in the quicksilver market and the exploration 

 was not pursued. 



The following figure illustrates a cross-section of the Redington mine, 

 showing the relation between the great ore deposit near the surface and the 

 more deep-seated fissures (Fig. 10). An accident having unfortunately hap- 

 pened to the original, this figure is not drawn to scale, but is founded on a 

 carefully prepared section to scale made from the mine maps, supplemented 

 by data furnished by the foremen of the mine. 



It is clear that faulting has taken place at the Redington under a com- 

 pressive strain, the result at lower levels being the distribution of the move- 

 ment over a series of parallel planes. This is n plienomenon which I have 



