Page:Popular Science Monthly Volume 79.djvu/426

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422
THE POPULAR SCIENCE MONTHLY
hyphenated word was joined on the previous page because of the intervening image.— Ineuw talk 23:22, 30 November 2013 (UTC) (Wikisource contributor note)
PSM V79 D426 Davis camp of coal claims on canyon creek.png
Davis Camp on Canton Creek. These buildings are on the claims of the Alaska Coal and Petroleum Company.
PSM V79 D426 View of slope glacier from the hartline claims.png
Looking toward Slope Glacier from the Hartline Claims. It shows the structure of the coal-bearing rocks in this part of the field.

sediments in the northeastern part of the field are narrow dikes and sills of diabase and basalt which are either Tertiary or post-Tertiary in age. The morainal deposits extend beyond the present limits of glaciation only a few miles.

The Tertiary sediments have been divided by Dr. Martin into three formations, namely, the Stillwater, the Kushtaka and the Tokun. The Stillwater is the oldest formation, and consists chiefly of sandstone and shale with a thickness of about 1,000 feet. The Kushtaka overlies the Stillwater conformably and is that part of the Tertiary which contains the beds of coal. It has a thickness of about 2,000 feet made up of coarse arkose, sandstone, shale and beds of coal. Complete sections