|An impressive feature of Devils Tower is the columns joints that cut the monolith. Most of the columns are 5-sided and taper from 6.5-8 feet (2-2.5 m) at the base to about 4 feet (1.3 m) at the top. They formed as the magma cooled from the surface downw ard and from the periphery inward. Photo by Steve Mattox, June 1979.|
Green, J. and Short, N.M., 1971, Volcanic landforms and surface features a photographic atlas and glossary: Springer Verlag, New York, 519 p.
Halvorson, D.L., 1980, Geology and petrology of the Devils Tower, Missouri Buttes, and Barlow Canyon area, Crook County, Wyoming: Grand Forks, University of North Dakota, Ph.D. dissertation, 218 p.
Karner, F.R., and Halvorson, D.L., 1987, The Devils Tower, Bear Lodge Mountains, Cenozoic igneous complex, in Beus, S.S., ed., Centennial Field Guide Volume 2 Rocky Mountain Section of the Geological Society of America, p. 161-164.
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