37G QUicKsiLVEi; deposits of the pacific slope 



Tlie Flagstaff is a olaim adjoining the Pioneer and very similar to it. 

 The ore-bearing gi-oinid is a stratnni of argillaceons sandstone impregnated 

 with metallic mercury, which is accompanied by a little cinnabar/ Pro- 

 fessor Whitney visited the region in 18(jl, when some of tiie mines were 

 being worked, and has published the following notes concerning tliem r 



Tlie Cincinnati is on the bill-side noar a steep canon, northeast of Pine Mount- 

 ain ; from it Mt. St. Helena bears S. 3'2° E., and the mine was estimated to Lave an 

 altitude of about two thousand five hundred feet. The prevailing rock is serpentine, 

 filled with fhreads and veinlets of quartz, running tlirough it in every direction, pre- 

 senting a rather peculiar appearance, as some of the quartz is in a crystallized form. 

 Both cinnabar and native mercury have been found here, but there was little appear- 

 ance of regularity in the deposit and no large mass of ore had been discovered. * * 



The Dead Brolce lies about one mile west of the Cincinnati. The rock here con- 

 sists of alternating layers of dark and light colored and partly decomposed quartzite ; 

 the strike is about N. 5° W.-S. 5° E., and their dip, which is to the west, about 45^. 

 On the east side of the ridge imperfect serpentine was seen, and a level had been 

 driven in it for 265 feet. The cinnabar, of which rich specimens had been procured, 

 was contained in a stratum about four inches wide and parallel with the formation. 



The rittsburg claim is one half a mile N. 15° W. from the Dead Broke, and some 

 cinnabar has been found here in serpentine. 



The Pioneer mine, which is south of j\It. Cobb and not far from the 



Little Cleysers, was also visited by Professor AVhitney, who says : 



The rock most nearly associated with the ore is the same peculiar siliceous variety 

 usually seen at the cinnabar mines of California, and it is inclosed on both sides by 

 serpentine. The strike of the metalliferous lode or vein was nearly northwest and 

 southeast. The metal exists here both in the form of the sulphuret, as cinrabar, and 

 in the native state ; indeed, so far as we know, it is one of the most remarkable local- 

 ities of native mercury ever discovered. The metal occurs disseminated in fine glob 

 ules through the vein-stone, or iu larger quantities in the interior of quartz geodes or 

 l)oekets. CTver six pounds have been saved from a single pocket, and one of the first 

 cavities broken into yielded four pounds three ounces of the metal, besides what was 

 unavoidably lost iu collecting. These facts are stated on the authority of Mr. B. C. 

 Wattles, the superintendent. * * * Considerable bituminous matter occurs here, 

 as iu most of the other mercury miues of the State, and some of the quartz geodes 

 contain bitumen. 



From Pine Flat, in Sonoma Count}', a definite belt of deposits extends 

 in a direction which is about 25° west of north. It is very noticeable on 

 the sketch map that this belt of deposits occurs at a considerable distance 

 from any volcanic rock, while, on the other hand, it passes within a mile of 



'UDpublishod rcjiort by L. Jauiii. -Geo). Survey Califoinin, Geology, vol. 1, j). 69. 



