LOS ANGELES-POSITION OF THE BITUMEN. 
113 
lie only mentions two localities, that near the village Santa Barbara, and this at the Pueblo Los 
Angeles, it is presumed he'reckons these as the only sources of his estimate. He does not state 
what the data of the calculations are. The actual quantity already poured out on the Santa 
Barbara shore is vastly greater than at Los Angeles—perhaps 6,000 tons would he an under 
estimate for Santa Barbara; hut as a source of asphaltum it is extinct, while that at Los 
Angeles is actively pouring out, although the accumulated overflow is much smaller. As a 
locality of asphaltum available for the present time, Santa Barbara is pre-eminent; as a source 
for future wants, Los Angeles is preferable. By following the line of upheaval on these hills, 
and making borings in the sandstone strata, the bitumen might he reached, and thus other sources 
than the natural well might he drawn upon. Dr. Trask values the asphaltum delivered in San 
Francisco at $16 per ton ; hut this is an excessive valuation according to the price at the well, 
or according to the calculations of freight from Santa Barbara northward; allowing the value to 
he $7 per ton, and in Los Angeles valley about 2,500 tons to he at present available, the 
actual present wealth of the valley in bitumen would he $17,500. This, of course, does not 
take into account the future supply. 
11. Bitumen of San Pedro hills. —This locality, south of Los Angeles valley, is a soft argillite, 
similar to those found further north in the Monica hills ; in these strata the bitumen leaks out 
in small quantity as at Rincon and San Buenaventura rivers ; no actual deposit has been met 
with as yet upon these hills. 
Further east, in the valley of San Gabriel mission, the asphalt again occurs in small 
quantity on the low hills nearest the mission. 
12. Bitumen of San Juan Capistrano .—This is taken for granted on mere report, as no 
observation was made ; it is said to occur a few miles inland above the mission in considerable 
amount. 
18. Bitumen of San Diego. —Here, as was stated at the commencement of this chapter, the 
asphaltum is observed on the seashore, washed up by the tide ; as the strata in the immediate 
vicinity of high water is the greenish arenaceous rock, in which it is elsewhere usually found 
associated along the Santa Barbara shore, the point of exudation cannot be far out under water. 
The strata dip toward the sea at False Bay and Point Loma, it is probable that its true position is 
not far distant from the shore. 
From the foregoing notice of the occurrence of bitumen at various points in the State, and of 
the accompanying strata, it appears evident that the beds in which it is found are accidental and 
not constant. From the outpouring being close to shore, it has happened more frequently that 
the softer and more recent of the deposits are those in which it is found; but that where it 
occurs inland it is met with infiltrated in a brownish yellow sandstone, which lies below the softer 
rocks along shore; in other words, it is sometimes met in the Santa Inez brownish sandstones, at 
others in the softer argillites of the San Luis series. The immediate cause of the outpouring is 
the upheaval of trachyte and amygdaloidal greenstone, and almost in contact with this rock it 
is at present oozing out; showing that this elevating force is not yet quiescent. At Santa 
Barbara, east of Point Rincon, and a few other localities, where magnesian talcose rock or 
scoriaceous lava is the upheaving cause, the action has ceased and the deposit is limited ; 
lastly, it may be remarked that numerous as are the serpentine protrusions among the mountain 
ranges, constituting some of the most powerful uplifts in the Coast mountains, and occupying a 
breadth of surface which is not equalled by any other volcanic rock, yet nowhere is bitumen 
found close to it. 
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