452 QUICKSILVER DEPOSITS OF THE rACIFIC SLOPE. 



duced more than any one of the otlier three. Idria, Huancavehca, and Cali- 

 fornia have each yielded pretty nearly the same amount from the dates of 

 discovery of the deposits to the present day, California taking the lowest 

 rank. But considering only the period which has elapsed since the mines 

 of the Pacific- Slope were first opened the case is different. Peru produced 

 nothing from 1850 to 1886 ; Idria, in round numbers, 300,000 flasks ; Alma- 

 den, 1,140,000; and California, 1,400,000, or nearly half the entire product 

 of the world. But California does not seem likely to maintain the same rank 

 among quicksilver producers in the future. 



Quicksilver was first recognized in California as occurring at the crop- 

 pings of the New Almaden mine by Andreas Castillero in 1845. His 

 means of testing the ore were quaint, but effectual, and he immediately 

 began production on a small scale. A large number of other deposits were 

 discovered at later dates, and some forty mines have produced metal, tliough 

 from some of these the yield has been trifling. Half a dozen of them 

 have yielded from 40,000 flasks upward and New Almaden has turned out 

 over 853,000. The sketch map of California (see Plate I) shows the dis- 

 tribution of some of the mines. 



Foreign occurrences of quicksilver. Thc aCCOUUt givBU of dcpOsltS kuOWU tO 



occur in foreign countries will not bear condensation, being in itself a brief 

 dio-est. The rocks inclosing quicksilver deposits are of very diverse ages, 

 rantrino- all the way from Archaean granites and schists to recent strata and 

 lavas. The lithological variety of the inclosing rocks is equally great, 

 including limestones, sandstones, and shales, many kinds of metamorphic 

 strata, and massive rocks of acid, neutral, and basic types. Cinnabar does 

 not even seem to exhibit any preference for one class of rocks rather than 

 another. It is clear that the mere age of the surrounding material is with- 

 out influence on the deposition of the ore and that the ore cannot in gen- 

 eral be derived from the walls of the deposits, for it is scarcely supposable 

 that this metal forms an original constituent of all sorts of rocks. 



A glance at the map (Plate II) shows that the quicksilver deposits 

 occur along the great axes of disturbance of the world. One of these is on 

 the line of the principal mountain system of Eurasia, for which I suggest 

 the name of Alpimalayan chain, because it includes the Alps and the Hima- 



