p 



216 



THE AURIFEROUS GRAVELS OF THE SIERRA NEVADA. 





The mass of Clermont is made up of talcose, silicious, and argillaceous slate, 

 having the usual northwest strike and dipping to the northeast at an angle 



of 50° — 70°. Near the summit of the mountain there is a very large out- 

 crop of quartz, and indeed the number of seams or veins of this mineral scat- 

 tered through the rock in this mountain is very great. The bed-rock is very 

 little covered by detrital material except just at the top, and here is a mass 

 of lava, having a length of about two miles in an easterly and westerly direc- 

 tion, and comparatively narrow north and south. It forms a capping of per- 

 haps 200 to 300 feet in thickness. This has been worked under, in the 

 Excelsior Claim, by a tunnel driven in, on the south side of the flow, for a 

 distance of 662 feet. Two men were occupied for five years in this work. 

 The material passed through, near the end of the tunnel, was a mixture of 

 pipe-clay and gravel irregularly interstratified. At the extreme end of the 

 workings, when examined by the writer, there was a thickness of about 

 seventeen feet of gravel, chiefly quartzose in character. A similar tunnel 

 was run in under the lava from the opposite or north side. Of the aurif- 

 erous character of the gravel nothing definite was learned. Of course, the 

 difficulty of getting water to this isolated and elevated point, on the very 

 summit of Clermont, will be apparent. A fact of interest observed here 

 was the occurrence of large logs of wood in the lava, partly carbonized, 

 and which had evidently been enveloped and borne along by the flowing 

 mass. 



Remarkable as is the above occurrence, that on the summit of Spanish 

 Peak is still more so, as the mountain is more isolated and higher, and does 

 not seem to be in the line of any known channel. With the exception of 

 the patch of gravel on Clermont, and a possible deposit under the lava at 

 the Buckeye House, previously referred to, the writer was not able to dis- 

 cover indications of any channel which could possibly connect with the one 

 on Spanish Peak, the summit of which is 7,058 feet above the sea-level. 



Spanish Peak was examined by the writer in 1866, when the existence of 

 a deposit of gravel, with a volcanic capping on the summit of the mountain, 

 was distinctly recognized. A tunnel had been run here to develop the pos- 

 sible channel, but the workings had been abandoned and were not then 

 accessible. Some years later Mr. J. A. Edman, of Meadow Valley, kindly 

 furnished the writer with a section of the formations noticed in running 



* According to barometical measurements made, as in the case of Clermont, with a station barometer 

 no nearer than Copperopolis. 



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