20 ELEVATION OF COAST KANGE — MODEKN ROCKS. 



level; Anterior to the Quaternary period, the ernpted rock tilted up their strata, which, 

 perhaps, did not reach the level of the ocean surface, and upon these smoothed edges were 

 de^josited the unconsolidated clays and local drift. They had not, however, fully appeared 

 ahove the surface of the ocean until the close of the Quaternary period. The elevated sea 

 beaches found distributed over so large an extent of country, from north to south, at a level of 

 from 100 to 150 feet above the sea, and containing species, all of which are now existing, show 

 how comparatively recent is the final elevation of the lower lands of the State, and places the 

 period of elevation of this range in the early portion of the Quaternary epoch. The plutonio 

 rocks of the coast hills also attest the comijarative newness of the land ; pumice, obsidian, 

 felspathic lava, trachyte, amygdaloidal greenstone, and serpentine. Volcanic rocks of the 

 latest kind are those which are commonly distributed both in the form of axes and veins, or 

 seams. Granite is also found, though not so extensive as a disturbing agent or an elevator of 

 a mountain ridge. When found in place it is an older rock than those previously mentioned, 

 being cut through and injected by them in many places ; but the granite in the coast mountains 

 is a modern granite, being either highly felspathic, passing into leucite, and even trachyte in 

 many places, or it is hornblendic, and passes into a hornblende porphyry ; micaceous granite is 

 very sparingly distributed in southern California. Tlie elevation of the Coast Range must have 

 taken place from two points, one in the north and one in the south ; the latter force commencing 

 in the southern part of San Luis Obispo and the eastern of Santa Barbara counties, and thence 

 extending north ; as the upheaving force passed northward, its power became spent, and unable 

 to lift the imjjosed strata ; a similar action from the north, acting in a soutlierly direction with 

 less vigor, produced an uplift, whose action ceased between latitude 37° and 38°. So that while 

 the consolidated crust of the State was uplifted at each end, it was quiescent, or nearly so, in 

 the middle ; and the two forces acting against each other may have produced a rupture of the 

 superficial strata, and even a depression of the surface below the sea level, in which the waters 

 of San Pablo, Suisun, and San Francisco, have taken their resting place. 



Depressions of the strata and fissures from east to west across the line of the mountain ranges 

 are common along the Pacific, north of this point, latitude 38°, and extend inland even east of 

 the Sierra Nevada,, In the course of these depressions rivers run. The Klamath and the 

 Columbia are examples ; which rivers might possibly never have emptied their waters into the 

 Pacific, but for this fracturing eifect produced by opposing volcanic forces. 



The upheaval of the Coast Ranges have brought to view only tertiary strata of the Miocene 

 group and beds of clay of the Quaternary period. These beds are thicker and more extensively 

 distributed in a connected series than anywhere else (known) on this continent. . In this respect 

 they rival or even excel the strata on the shores of the Mediterranean. It is interesting to 

 trace the resemblance of form and outline of hills produced by similarity of geological circum- 

 stances, whether of formation or upheaval. Many of the scenes of California resemble those on 

 the shores of northern Greece, Roumelia, northern Syria, and the Calabrian peninsula. 



The strata known as " paleozoic," have not been found in the southern section of the State. 

 It would be hazarding, perhaps, too much to say that they do not exist, although some cir- 

 cumstances might warrant it. The tertiary conglomerate has been found, in very many 

 instances, within a few yards of the granite, and occasionally in actual contact. Those rocks, 

 which are fossiliferous, are tertiary in character. There were but two varieties of rock found, 

 perhaps, not of that age— primary and metamorphic limestone and gneiss ; the former was found 

 along the Sierra Nevada and the Cordilleras, which extend south into Mexico, and it was 



