PETROLEUM POSSIBILITIES OF FLORIDA 
45 
The theories as to the origin of petroleum in nature that have been 
proposed may be divided into those that ascribe their origin to inorganic 
sources and those that recognize an organic source for petroleum. The 
inorganic theories are diverse, but those best known involve the as¬ 
sumption of the existence of carbides deep within the earth, from which 
hydrocarbons are formed. 
The organic theories include those which ascribe the origin of petro¬ 
leum to animal sources, those that ascribe the origin to vegetable sources, 
and those that ascribe the origin to vegetable and animal sources com¬ 
bined. The theory of origin from animal remains maintains that the 
petroleum originates from the slow decomposition of the fatty sub¬ 
stances of animals imbedded in the rocks. Those who regard-petroleum 
as derived from vegetable matter, for the most part name the lower 
plants as the probable source, including cellular marine plants, fucoids, 
seamuds, algae, and diatoms. Those who recognize that the petroleum 
oils may be derived in part from animal and in part from vegetable 
sources, are probably in majority at the present time. 
The geologic relations of petroleum deposits undoubtedly support the 
organic theory of its origin. The diversity of petroleums and the vary¬ 
ing kinds of sedimentary rock with which it is associated argues for the 
probable derivation, in some instances, from animal remains, and at 
other places from plant remains, or in other instances a combined origin 
from animals and plants imbedded, as they often are, in the same forma¬ 
tion. 
In the application of geology to the location of petroleum deposits, 
the organic theory of origin is very generally applied, and deposits high 
in organic matter are universally sought as one of the conditions favor¬ 
able to the accumulation of oil in commercial quantities. 
THE ACCUMULATION OF OIL AND GAS INTO DEPOSITS 
OF COMMERCIAL VALUE 
In the preceding pages it has been stated that a probable source of oil 
and gas is in the organic matter, animal and plant, imbedded in the 
rocks. If such is true, there yet remains the problem of accounting for 
its accumulation in local deposits in sufficient amounts to be of commer¬ 
cial value. The organic materials in the rocks are widely disseminated, 
