142 
ALASKAN MINERAL RESOURCES IN 1904, 
[bull. 259. 
include, therefore, only the high land lying above and between the 
tidal flats and river flats and the glaciers. 
The coal-bearing rocks have been designated by the writer as the 
Kushtaka formation, which contains fossil plants of supposed Oligo- 
cene age, and is the probable equivalent of at least part of the Kenai 
formation of the Cook Inlet region. This formation has the area] 
extent described above and is adjoined on the south by the Katalla 
formation, which it probably overlies. Its area! and structural rela- 
tion to other formations to the west, north, and east is not known. 
Fig. 9.— Sketch map of Bering River coal field, showing location of openings from which samples o 
coal analyzed were obtained. 
The Kushtaka formation consists of probably several thousand fee 
of sandstone, shales, arkose, and volcanic ash, with many coal seams 
The prevailing strike over the greater part of the coal-bearing ares 
is about N. 40° E. The prevailing dip is northwest at an angle o 
about 45°. This monoclinal dip is apparently modified by only tw<< 
folds within the region now known. There is at least one fault o 
considerable length and displacement, and several smaller ones. 
One of these folds is an anticline exposed near the headwaters o 
Queen Creek (fig. 9) on the divide between the Shepherd Creek am 
Lake Kushtaka valleys. The rocks here have a strike of N. 64° ti 
66° E. , with a northwest dip of 42° on the northwest flank of the f ol 
