HAYES AND 
KENNEDY 
D ] ACCUMULATION OF OIL. 143 
by oil. This condition, however, is probably very rarely present in 
the thoroughly saturated beds underlying the Coastal Plain. 
In almost every deep well which has been drilled in the Coastal 
Plain small quantities of oil have been found, generally at several 
horizons. While this is not sufficiently abundant to be of value, it 
indicates the extremely wide distribution of the oil through these 
formations and the enormous aggregate which they must contain. If 
these beds were regular in thickness and character, like those under- 
lying the Appalachian field, and were similarly folded, the oil would 
travel to the crests of the anticlines and accumulate in long, narrow 
pools. The beds of this region, however, are most irregular. No two 
well sections, even if closely adjoining, exactly correspond. In Ohio 
alone the Berea sandstone extends over 15,000 square miles with 
scarcely any variation in thickness and composition. In the Coastal 
Plain, on the other hand, no single bed can be traced without material 
modification over 100 square miles. The underlying formations are 
composed of a vast number of overlapping lenses and the stratigraphic 
relations are therefore exceedingly complex. The conditions are 
unfavorable for the transfer of oil from place to place, and the result 
is that the most of it has remained disseminated through the beds. 
The Coastal Plain formations have a general southeastward dip of a 
few feet to the mile, but this has apparently not been sufficient to 
enable the oil to overcome the obstacles occasioned Irf the irregularity 
in the character of the bed. Under these conditions some agency in 
addition to mere difference in specific gravity between the oil and 
water was required for the segregation of the oil. This was found in 
the circulation of the water contained in the beds. The agency of 
circulating waters in the accumulation, not only of the oil in the 
Coastal Plain pools, but also of the associated sulphur, dolomite, and 
salt, has recently been suggested ly^ Hill. 05 
The hypothesis is as follows: The oil and salt pockets of the Texas Coastal Plain 
are probably not indigenous to the strata in which they are found, but are the 
resultant products of columns of hot saline waters which have ascended, under 
hydrostatic pressure, at points along lines of structural weakness, through thou- 
sands of feet of shale, sand, and marine littoral sediments of the Coastal Plain 
section, through which oil and sand are disseminated in more or less minute 
quantities. The oil, with sulphur, may have been floated upward on these waters, 
and the salt and dolomite may have been crystallized from the saturated solution. 
The channels of these ascending waters may have been in places of structural 
weakness, such as fissures, which probably at one time continued to the surface, 
but may have been sealed by the deposition of the later overlapping strata now 
capping the oil pools. 
Many facts may be adduced in support of this hypothesis, although 
it must be admitted that it presents some serious difficulties. The 
mode of accumulation of the enormous masses of rock salt which 
occur in the Louisiana Salt Islands, in Damon Mound, in High Island, 
n Robert T. Hill, The Beaumont oil field, with notes on the other oil fields of the Texas region: 
Jour. Franklin Inst., 1902. 
