NOTES ON THE PETROLEUM FIELDS OF ALASKA. 
By George C. Martin. 
INTRODUCTION. 
The attempts to develop oil fields in Alaska, which were begun in 
L901, were continued during the summer of 1904. The writer has 
already a described to some extent the geology and oil indications in 
the Controller Bay, Cook Inlet, and Cold Ba}^ fields. These fields, 
together with much intervening territory, were revisited during the 
summer of 1904. The following pages contain the additional knowl- 
edge gained during the past season and a statement of the progress of 
development. 
CONTROLLER BAY PETROLEUM FIELD. 
LOCATION. 
The Controller Bay petroleum field is situated on the shores of Con- 
troller Bay, about 25 miles southeast of the mouth of Copper River, 
in latitude 60° 10' N., longtitude 114° 20' W. The region withim 
which there are indications of petroleum, and where wells have 
been drilled, is about 20 miles long from east to west, and 7 miles wide 
from north to south, and is situated between Bering Lake and Con- 
troller Bay and between the, ridge west of Katalia and the Mount i 
Nitchawak region. 
GEOLOGY. 
STRATIGRAPHY. 
The rocks of the Controller Bay region include a series of complex] 
semimetamorphosed beds, a series of oil-bearing Eocene shales (Katalh 
formation), a series of Oligocene coal measures (Kushtaka formation) 
a series of Miocene conglomerates, sandstones, and shales, a fev j 
igneous rocks, and a large area of alluvial and glacial deposits. O 
these the petroleum belt proper includes only the Katalia formation 
some igneous rocks, and alluvial deposits. 
The Katalia formation consists of a series of dark argillaceous an< 
carbonaceous shales, with occasional bands of sandstone, limestone 
conglomerate, and volcanic ash. These are the rocks through whicl 
the petroleum of the region reaches the surface. They are typical! 
a Bull.' U. S. Geol. Survey No. 225, 1904, pp. 365-382. 
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