OAKVILLE AND BELLA UNION MINES. 377 



the group of hot sulplmr springs miscalled geysers. Some of these .springs 

 reach the boiling-point and emit .steam. They are very numerous and active 

 and are regarded as one of the sights of California. Tiieir character is such 

 as is almost universally attributed to volcanic activity. Their presence near 

 the quicksilver mines therefore indicates that the remoteness of the deposits 

 of cinnabar from the nearest lavas does not preclude a relation between vol- 

 canic activity and ore deposition. The mines of this group are the Sonoma, 

 the Rattlesnake, the Little Missouri, the Oakland, the Kentucky, and the 

 Cloverdale. The Kattlesnake produced only about .sixty-five flasks of Cjuick- 

 silver, but it is a noteworthy fact that this product was obtained almost 

 entirely from uative quicksilver disseminated in a friable sandstone. An 

 unusual quantity of oily bitumen accompanied this ore, and it is recorded 

 that there were special arrangements to burn the hydrocarbons because of 

 the quantity of soot which they formed in the condensers.' Though most 

 of the ore was an impregnated unindurated sandstone, the usual opaline 

 rock also occurred here and sometimes showed geodes containing oil. The 

 Oakland mine, as stated in the table of production, Chapter I, produced 

 G,831 flasks, and may perhaps be reopened under favorable circumstances 

 The product of the Cloverdale was 2,G6l flasks, but the Kentucky only 

 turned out 54 flasks. Another small mine, beyond the limits of the map, 

 is the Livermore. It lies two miles west of the junction of Pluton Creek 

 and Sulphur Creek. 



oakviue and Bella Union — Small quautitics of ciuuabar occur in the hills 

 bounding Napa Valle}' on the west, about half way between Calistoga and 

 Napa City. The principal deposits are on two adjoining claims, the Bella 

 Union and the Oakville. The rock is siliceous slate, associated with serpen- 

 tine. The slates strike north and south and dip at 60° or 70° westward 

 toward the summit of the range. The ore is exclusively cinnabar, accom- 

 panied by pyrite and calcite. It forms seams in the slates and irregular 

 bunches connected by narrow stringers of ore. The Bella Union has pro- 

 duced some metal.^ 



' T. Eglestou, Traus. Am. Inst. Min. Eng., vol. 3, p. 273. 



^ The informatiou concerning these mines is derived from an unpublished report of Mr. C. A. Luck- 

 hardt. 



