GEOLOGY. 65 



The asphaltum generally comes up through sandstone. The 

 springs of Santa Barbara seem to have ceased to flow, while 

 those in Los Angeles county are still active. It is supposed 

 that the amount lying on the surface at the various deposits is 

 not less than five thousand tons. 



§ 46. Other Minerals. — Iron pyrites, or the sulphuret of 

 iron, is found with gold in many of the quartz-veins. Iron is 

 found also in a number of chalybeate springs. Iron-ore con- 

 taining, it is said, 83 per cent, of metal, has been found near 

 Auburn, in Placer county ; and the assessor of Shasta county, 

 in his report for 1857, said "rich iron-ore" had been found in 

 that county. Magnetic iron ore is found in the Canada de las 

 XJvas, and at Williamson's Pass. 



Tin-ore, of the kind called "tin-stone," of a rich quality, has 

 been found in a large vein at Temascal, in San Bernardino 

 county ; and it is reported that another lode of similar charac- 

 ter has been found in the valley of White River, Buena Vista 

 county. 



Galena has been found in Humbug valley, Siskiyou county ; 

 in Tuolumne county ; and on the banks of the Cosumnes River, 

 in El Dorado county. Plumbago has been discovered near 

 Columbia, Tuolumne county. 



Cobalt is found, in various ores, in many counties in the 

 state. 



At San Emidio, about twenty miles westward from Tejon 

 Pass, is a rich and large lode of sulphuret of antimony ; the 

 vein is from four to twelve feet thick, and is about six thou- 

 sand feet above the level of the sea. 



Arsenic exists in many of the lodes of auriferous quartz, in 

 the argentiferous lodes at Esmeralda and Coso, and in the an- 

 timonial ore of San Emidio. 



Sulphur is abundant in California. It exists in large beds 

 near the Geysers, in Sonoma county ; near Clear Lake, in 

 Napa county; in San Diego county, thirty miles northward 

 from the town of that name, and twelve miles from the sea ; 

 near the sea- shore, fifteen miles eastward from Santa Barbara; 



