20 
ELEVATION OF COAST RANGE—MODERN ROCKS. 
level. Anterior to the Quaternary period, the erupted rock tilted up their strata, which, 
perhaps, did not reach the level of the ocean surface, and upon these smoothed edges were 
deposited the unconsolidated clays and local drift. They had not, however, fully appeared 
above 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 plutonic 
rocks of the coast hills also attest the comparative 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; hut 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. The elevation of the Coast Eange 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 imposed strata ; a similar action from the north, acting in a southerly direction with 
less vigor, produced an uplift, whose action ceased between latitude 31° 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, hut for this fracturing effect 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 “ palaeozoic,” 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 
