DISTEIBUTIOX OF CINIsABAE. 51 



exhibit a partiality it is sandstone, but rich deposits are common in hme- 

 stone, shale or slate, and serpentine, and are not unknown in other rocks. 

 No definite relation between the lithological character of the inclosing 

 rocks and the richness of deposits is apparent from the descriptions. 



Relations to lines of disturbance — Comparlson of tlio skctcli-niap (PI. 11) with 

 any physical chart o( the globe shows that the quicksilver deposits bear 

 a most intimate relation to lines of disturbance. Tlie great mountain 

 chain of Eurasia includes the Pyrenees, the Alps, and the Himalayas. 

 This, which might conveniently be called the Alpimalayan chain, breaks up 

 into divergent ranges at each end, or in Spain and China. The larger part 

 of the known occurrences of Eurasia are distributed along the Alpima- 

 layan chain, and their frequency is very nearly proportionate to our knowl- 

 edge of the regions in which they occur. There is little reason to doubt 

 that, when Kurdistan, Afghanistan, and Thibet are better known, quicksil- 

 ver localities as }'et undiscovered will be found. At the western end of the 

 chain the quicksilver deposits, like the ranges, scatter. This appears also 

 to be the case in China, since, according to Mr. R. Pumpelly, cinnal^ar oc- 

 curs in ten out of the eighteen provinces of China; but I have not thought 

 the information sufficiently definite to justify me in entering the localities 

 on the map. The chief localities not immediately in the Alpimalayan 

 chain are those on the western coast of Italy. These deposits form a line 

 which may manifestly be regarded as a mere offshoot from the great belt of 

 disturbance. The outlying range of the Ural Mountains is marked by a 

 few traces of cinnabar. The famous deposit of eastern Siberia seems quite 

 isolated. The occurrences of Kamtschatka and Ja[)an lie along a line of 

 disturbance marked by a series of active and extinct volcanoes, and the 

 deposits of the East Indian islands are associated with similar evidences of 

 dynamic action. 



The American deposits from Alaska to Chili lie near the coast, along 

 the western ranges of the Cordillera system, and the line in which they oc- 

 cur is mai'ked from one end to the other by manifold evidences of profound 

 disturbance. The Brazilian deposits, like that of Nertschinsk, are in mount- 

 ainous, metalliferous regions, but seem only remotely connected with the 



