THE PACIFIC SLOPE. 241 



CALIFORNIA. 



2.12.06. Geology. The topography and geology of northern 

 California have been but recently made clear. Diller considers 

 that the southern end of the Cascade range is Mount Shasta ; 

 that the Sierras proper terminate near the north fork of the 

 Feather River, but the line is continued about fifty miles farther 

 north, in the Lassens Peak volcanic ridge, and that all else west 

 and south of Mount Shasta belong to the Coast range. Central 

 California, as is well known, has the Sierras on the east, the great 

 Sacramento Valley in the middle, with the Coast range on the 

 west. The arid regions of the Great Basin just touch the north- 

 eastern corner, but on the southern extremity they swing around 

 and form a large part of the State. The Great Basin portion is 

 formed by Quaternary lake deposits. The Sierras consist of cen- 

 tral granite and gneiss, with great developments of slates and 

 eruptives on their flanks. The excessive metamorphism has large- 

 ly destroyed the fossils, but enough have been found to prove that 

 while in large part Jurassic, yet Carboniferous and Cretaceous 

 representatives are also present. The western slopes have the 

 mantles of gravel, which have furnished so much gold, and with 

 these are large outflows of basalt. The upheaval of the Sierras 

 occurred before the middle Cretaceous time. The Coast range con- 

 sists of rocks of late Cretaceous and early Tertiary age, extending 

 into the Miocene. They were upheaved in post-Miocene time. 

 Great outbreaks of andesite also occurred, and later basalts. The 

 principal product of California is gold, but recently a district 

 which furnishes considerable silver has been developed. This 

 will first be described, in order to lead up to gold. The copper 

 and iron resources have already been mentioned, and the mercury, 

 antimony, and chromium deposits remain for description after the 

 precious metals. 1 



1 G. F. Becker, " Notes on the Early Cretaceous of California," Amer. 

 Jour. Sci., iii., II. 201. " Antiquities from under Tuolumne Table Moun- 

 tain, California," G. S. A., II. 189. "Cretaceous Metamorphic Rocks of 

 California," Amer. Jour. Sci., iii., XXXI. 348. "Structure of a Portion 

 of the Sierra Nevada of California," G. S. A., II. 50. "Notes on the 

 Stratigraphy of Cali r ornia," Bull 19, U. S. Geol. Survey. W. P. Blake, 

 " Notes on California," Amer. Jour. Sci., ii., XVIII. 441. W. H. Brewer 

 epitomizes Whitney's report, Amer. Jour. Sci., ii., XLI. 231; also 351. J. 

 D. Dana, "Notes on Upper California," Amer. Jour. Sci., ii., VII. 376. 

 J. S. Diller, " Geology of the Lassen Peak District," Eighth Ann. Eep. Di- 



