OIL OF THE SANTA MARIA DISTRICT. 
Ill 
cause the relatively high percentage of nitrogen found in the Califor¬ 
nia oils. 
Fish skeletons are sometimes found in the shale, and flat impres¬ 
sions, large and small, that appear to be the scales of fish are abun¬ 
dant and very characteristic of certain portions of this formation, 
seeming to show that fish remains were in sufficient abundance to 
add at least something to the oil and to supply a portion of the nitro¬ 
gen. On the other hand, these fossilized parts may have been origi¬ 
nally separated from the tissue before they dropped to the ocean 
bottom or before being buried in the deposit, as by far the greater 
number of fish are believed to die violent deaths and to serve as food 
for larger fish or other animals. 
Other animal organisms which were present and which may have 
contributed hydrocarbons and nitrogen were sponges, mollusks, and 
crustaceans—such as crabs and possibly ostracods. The impres¬ 
sions of seaweed occur in the shale but sparingly, probably because 
plants of this kind are restricted in habitat to shallower water than 
that in which it is believed the greater part of the Monterey was laid 
down, so that it is not probable that these plants have been large 
contributors to the material of the oil. 
It is certain that there was a sufficiency of organic material in¬ 
cluded with the Monterey deposits to give rise to a vast quantity of 
petroleum, as is proved by a rough estimate based on low calcula¬ 
tions of the amount of such material present. If the area covered 
by the Monterey formation in the Santa Maria district, including 
territory surely covered by it whether the formation now outcrops 
there or not, be taken as 800 square miles and the thickness of the 
formation as half a mile, the total volume of the deposit would be 
400 cubic miles. These figures are low, especially in view of the fact 
that the average thickness and the areal extent of the formation were 
much greater when the oil began to be accumulated than at present. 
If we regard for the moment the diatoms alone to be the source of 
the oil, and only 1 per cent of the formation to be made up of these 
organisms, there would be 4 cubic miles of diatoms; and if we sup¬ 
pose further, simply as a rough guess, that these forms gave rise to 
an amount of petroleum equaling 1 per cent of their volume, we 
would have 1,000,000,000 barrels of oil as the amount distilled 
within the Monterey in this district, or more than thirty-three times 
the total production of oil in California for 1904, or eight times the 
production in the United States for the same year. According to 
Albert Mann, who has recently made an extensive study of diatoms, 
these plants when living secrete algal wax or oil in amounts varying 
from 0.75 per cent to as much as 4 per cent of their total volume. 
The amount of petroleum that might be derived from the diatoms 
is entirely unknown; but if the figure assumed hypothetically as 
