kARTIN.] 
PETROLEUM FIELDS. 133 
cline. The westernmost is on the eastern Hank, and about halfway 
down the Katalla Valley anticline. Those in the valley of Burls Creek 
are in a less certain structural position. The gas springs on the banks 
of the Katalla River are probably located on or near the crest of the 
Katalla Valley anticline. It seems probable that in this, as in most 
other fields, the occurrence of oil is controlled by the structure. The 
location of the anticlines and the structural position of the strata out- 
cropping at the lines of seepages will probably prove to be the safest 
guide in the location of the wells. 
THE COOK INLET PETROLEUM FIELDS. 
But little of economic value can be added to the description of the 
structure as given in earlier publications." The Mesozoic rocks are 
much thicker than was previously estimated. The Middle and Upper 
Jurassic rocks, overling the surface rock where the wells are being 
drilled, are about 7,000 feet thick. The underlying beds probably 
consist of about 1,000 feet of Middle Jurassic, an unknown amount 
of Lower Jurassic, and probably at least 2,000 feet of Triassic. The 
structure has already been described. 
The first well at Oil Bay was begun in 1898 and has been drilled to 
I depth of somewhat over 1,000 feet. No log of this well or any very 
authentic information can be obtained, as the property has changed 
management several times. It is reported that gas was encountered 
all the way below 190 feet, and that considerable oil was found at a 
depth of 700 feet. The flow of oil is reported as having- been esti- 
mated at 50 barrels. On drilling deeper a strong water pressure was 
encountered, which shut off the flow of oil. The well is now over 1,000 
feet in depth and affords a continuous flow of gas, which at times 
becomes very strong. Attempts have been made to shut off the flow of 
water and either recover the lost oil or drill deeper, but without 
success. 
A second well, located about a quarter of a mile west of the older 
one at Oil Bay, was drilled during the summer of 1904. 
Record of well as reported by August Bowser. 
Feet. 
Sandstone 200 
Shale - 120 
Oil and some gas 1 
hale (caving) 129 
\ The well was abandoned at a depth of 450 feet because the shale 
Eaved so badly. 
A third well, located about 250 feet south of the last, was also drilled 
luring the summer of 1904. 
The general sequence of strata was the same as in the last well, the 
a Bull. U. S. Geol. Survey No. 225, 1904, pp. 376-379; Bull. U. S. Geol. Survey No 250, 1905. 
