16 PETROLEUM OF PACIFIC COAST OF ALASKA. [bull. 250. 
The extreme southern end of Kayak Island, known as Cape St. 
Elias, rises in a high peak, having the appearance of a volcanic plug. 
The rock is of light color, has a columnar jointing, and is somewhat 
exfoliated and has been identified microscopically as a trachyte. 
PLEISTOCENE AND RECENT DEPOSITS. 
At the southern end of Wingham Island are good exposures of 
horizontal or gently dipping unconsolidated sand, clays, and gravels. 
These strata rest unconformably upon the upturned edges of the 
shales, which make up the larger part of the island. They are fos- 
siliferous, containing Ostrea and a variety of other pelecypods and 
gastropods, which are surely not older than Pliocene. It is possible, 
and from the structural relations of these beds as compared with 
the other Tertiary and Quaternary deposits of the coast of Alaska, 
it seems probable that these beds are, indeed, very late Tertiary 
or post-Tertiary. They are exposed at an elevation of from 10 to 30 
feet, and possibly date from the most recent elevation of the coast. 
Gravels which are accompanied by finer deposits and carry no fossils 
are exposed in a similar position along the bluffs near and to the 
west of Fox Islands, and probably also represent the most recent 
elevation. 
The eastern shore of Bering River and Controller Bay, from a 
point slightly below the mouth of Stillwater Creek to the ocean, is 
a flat plain of sand and mud, constantly growing by the addition of 
sediment which the streams from the soutliAvestern margin of the 
Bering Glacier carry and deposit along their courses and at their 
mouths. Mount Nitchawak, Mount Campbell, Mount Gandil, and 
other peaks rise like islands from this plain, and it seems certain 
that a very short time ago they were islands in an older extension of 
Controller Bay, then as now being filled by the sediment of these 
glacial streams. This younger fluviatile Quaternary formation ex- 
tends along the northern bank of Bering River from a point about 3 
miles below the mouth of Stillwater Creek to Bering Lake. It also 
extends up the valley of Shepherd Creek for a distance of about 4 
miles above the lake, and apparently to the southern end of Lake 
Kushtaka. The valley of Katalla River and of the stream which 
heads near it and flows into Bering Lake is floored with the same 
material, as are also the lower courses of most other streams which 
enter Controller Bay. The deposits are known to have a thickness 
of over 580 feet at one point on Bering River, and of over 240 feet in 
the Katalla Valley. 
Another series of deposits contemporaneous with the last, yet differ- 
ent in origin, are the beaches, islands, and bars which the waves of | 
the ocean are building along these shores. Okalee sand spit and the 
