martin.] IGNEOUS ROCKS OF CONTROLLER RAY REGION. 15 
lies in an adjacent belt to the south of it, by the presence of coal 
seams, the predominance of sandstone over shale, and the coarseness 
of the sediments. It evidently adjoins on the north a belt of crys- 
talline formations, of which numerous fragments have been trans- 
ported into this region by streams and glaciers. The stratigraphic 
relation to the formations existing in the adjacent areas is not 
known, except that the general structure of the region is such as to 
indicate that it overlies the Katalla formation, which probably occu- 
pies a low horizon in the Tertiary. 
The formation has yielded the following fossils (as determined by 
Dr. F. H. Knowlton) : Salix sp. cf. S. varians, Corylus macquarrii, 
Betula prisca, and Betula grandi folia. All of these occur also at Port 
Graham in the Kenai formation, and are representative of the so- 
called Arctic Miocene or Oligocene. Poorly preserved fragments, 
which probably represent species of Zizyphiis and Lauras were also 
found. 
MIOCENE ROCKS. 
The rocks exposed on the north shore of Kayak Island consist of 
beds of conglomerate, sandstone, and shale, with a marine fauna in 
which Dr. W. H. Dall and Dr. Ralph Arnold have identified the fol- 
lowing species: Lecla sp. A. (smooth), Yoldia aff. scissurata Dall, 
Yoldia aff. thraciaformis Dall, Macoma cf. calcarea Gmel., Callista 
sp., Natica sp., Chrysodomus sp. A., Ghrysodomus sp. B., Rostellites 
cf. indurata Conrad. They are of the opinion that this fauna is upper 
Oligocene or lower Miocene, and is the equivalent of the marine 
faunas at Unga and Cape Yaktag. 
IGNEOUS ROCKS. 
Several igneous masses were seen on the west shore of Bering 
River near its mouth, and include dikes of a light-colored, fine- 
grained rock, tentatively determined under the microscope to be a 
micro-granite. About one-half mile above this point and just below 
the Chilkat Indian village are numerous exposures of a fine-grained, 
dark-green, igneous rock, which upon examination proves to be a 
chloritized tuff. 
A massive, light-colored, medium-grained rock is exposed in the 
north bank of Bering River at the south end of Carbon Mountain, 
and the island in the river at this point is perhaps of the same com- 
position. It is possibly of igneous origin and may have furnished 
the heat that produced the coke occurring in the vicinity. Speci- 
mens of this massive rock were collected but were lost in shipment, 
and no determination of either its name or its general character can be 
made. Several large masses of a basic glassy rock have broken up 
through the Miocene rocks on the north shore of Kayak Island. 
