YELLOWSTONE PETRIFIED FORESTS

 

 

 

Sequoia stump at Specimen Ridge

 

Sequoia stump at Specimen Ridge

 

 

Growth rings - The excellent preservation of much of the wood is suitable for dendrochronology

 

 

Pattern of strong concentric and radial fracturing

 

 

Thin section from Michael Arct's 1991 dissertation on dendrochronology of the forests.

 

 

Mountain man Jim Bridger in the 1830s may have been the first white man to see the stone trees.  It is believed that the re-telling of his report of them became exaggerated - "Petrified birds a sittin' on peetrified trees a singin' peetrified songs in the peetrified air. The flowers and leaves and grass was peetrified, and they shone in a peculiar moonlight that was peetrified too".

 

The National Park Service describes the 35-55 million year old petrified forests at Yellowstone as the "world's largest".  These "forests of stone" can best be seen on Specimen Ridge near Lamar Valley in the Gallatin Region.  This is in the northwest part of the park, in the Gallatin National Forest Range. The Gallatin National Forest shares its borders with Yellowstone National Park, covering 1.8 million acres in southwestern Montana.

Various exposed upright trees may extend up to 6m above ground level, and one which is almost 15m tall may be the tallest standing petrified tree in the world.

 

Within the Eocene Absaroka Volcanic Supergroup, petrified wood occurs in both the Sepulcher Formation and the Lamar River Formation.  The greatest sequence of superimposed fossil forest levels may be at Specimen Creek, where 65 or more levels are discerned by some (an early count was 27 levels) (Fritz, 1985).

 

Nearly 150 species of fossil plants from Yellowstone have been described (exclusive of palynological specimens), including ferns, horsetail rushes, conifers and many deciduous plants such as sycamores, walnuts, oaks, chestnuts, soapberries, maples, and hickories. Seqouia is the dominant conifer. This type of assemblage reflects a warm temperature sub-tropical environment (Dorf 1980).

 

In his report in the Hayden Survey in 1878, Holmes made the first reference to Yellowstone's fossil forests. The report identified the petrified trees located on the north slope of Amethyst Mountain opposite the mouth of Soda Butte Creek, about eight miles southeast of Junction Butte.  Tillman published a popular account of the fossil forests in 1893 and they were described by Knowlton in 1895.  Subsequently, Knowlton (1899) published a complete study of the Yellowstone fossil forests in a comprehensive monograph that identified 147 different species and provided a detailed taxonomic treatment of the fossil plants, especially the leaf impressions. 

 

Knowlton desribed the most remarkable fossil forest as being on the northwest end of Specimen Ridge, where it covers several acres on a steep hillside about opposite the mouth of Slough Creek, a mile southeast of Junction Butte.  It was first brought to scientific attention by E. C. Alderson of Bozeman, Montana, who showed it to Knowlton in 1887.

 

At Specimen Ridge most of the trees project well above the surface, including hundreds of trunks from 1 to 8 feet in diameter and from 1 to 20 feet high, with the tallest more than 40 feet. Just beneath the largest known tree in Yellowstone (26.5 feet by 12 feet), which contains large roots, are two trees that are 9 feet in circumference and 20 feet high. Fossilized bark is preserved at this locality.  Tillman (1893) reported channeling and burrowing of worms or other insects occur in some petrified tree bark.

 

The first known map of the Gallatin Petrified Forest is found in a 1935 report, "Petrified Sequoia Trees in the Northwest Corner of Yellowstone National Park" by Dr. Paul A. Young of Bozeman.  He identified and mapped 21 standing trees in the Gallatin/Specimen Creek area and noted the discovery of leaf impressions of poplar, willow, and magnolia trees.  After mapping the trees, Young concluded in his report, "May the Officials of Yellowstone National Park please guard these secrets until they can adequately protect the Sequoias."  After the opening of the Gallatin River road in 1911 specimen hunters had pillaged the area. 

 

Andrews (1939) surveyed the Gallatin region of the park in the 1930s, collecting specimens in the Gallatin Petrified Forest in 1936. He reported at least 12 successive layers of fossil forest around Bighorn Peak, predominantly consisting of Sequoia magnifica, and fossil impressions of S. langsdorfi along Bighorn Creek. The petrified trees are preserved in the Eocene Sepulcher Formation.

 

Dendrochronology was attempted by A.E. Douglas in 1929-1930 but he found no correlations.  In 1979 and 1991 Michael Arct obtained some cross-matching at Specimen Ridge but others regard such as doubtful.  

 

 

 

REFERENCES

 

Arct, M. J., 1979.  Dendoecology in Yellowstone Fossil Forests. M.S. thesis,  Loma Linda University.

 

Arct, M. J., 1991.  Dendroecology in the Fossil Forests of the Specimen Creek Area, Yellowstone National Park.  Ph.D. dissertation, Loma Linda University.

Ammons, R., Fritz, W.J., Ammons, R.B. and Ammons, A., 1987.  Cross identification of Ring Structures in Eocene Tree (Sequoia magnifica) from the Specimen Ridge Locality of the Yellowstone Fossil Forests. Paleogeography, Paleoclimatology, Paleoecology, 60, pp. 97-108.

Andrews, H.N., 1939.  Notes on the fossil flora of Yellowstone National Park with particular reference to the Gallatin region. American Midland Naturalist 21(2), pp. 454-460.

Andrews, H.N. and Lenz, L.W., 1946.  The Gallatin Fossil Forest (Yellowstone National Park). Missouri Botanical Gardens Annual, 33, pp. 309-313.

Arno, S.F. and K.M. Sneck., 1977.  A method for determining fire history in coniferous forests of the

mountain west. General Technical Report INT-42. Ogden, UT. USFS Intermountain Research Station.

 

Arnold, C.A., 1947.  An Introduction to Paleobotany. McGraw-Hill, NY. 433 pp.

 

Chapman, W. and Chapman, L., 1935.  The petrified forest. Natural History Magazine, May, pp. 382-393.

 

Coffin, H., 1976.  Orientation of trees in the Yellowstone Petrified Forests. Journal Paleontology 50(3), pp. 539-543.

 

Cook, E.R. and Kairiukstis, L.A. (Eds.), 1990.  Methods of Dendrochronology. Kluwer, 394 pp.

 

Daniels, F.J., 1988.   Petrified Wood: the world of fossilized wood, conifers, ferns and cycads. Western Colorado Publishing Company, Grand Junction, CO.

Dorf, E., 1964.  The petrified forests of Yellowstone Park. Scientific American 210(4), pp. 106-114.

Dorf, E., 1974.  Early Tertiary fossil forests in Yellowstone Park. Pages 108-110 in Rock Mechanics: The American Northwest, Third International Congress on Rock Mechanics.

Dorf, E., 1980.  Petrified forests of Yellowstone. U.S. Government Printing Office, Washington, D.C. 12pp.

Field, L.G., 1983.  The Gallatin Petrified Forest. Lapidary Journal 37(8), pp. 1218-1223.

Fisk, L.H., 1976.  Palynology of the Amethyst Mountain "Fossil Forest", Yellowstone National Park, Wyoming. Ph.D. Thesis, Loma Linda University, Loma Linda, California. 340pp.

Fisk, L.H., 1976.  The Gallatin "Petrified Forest": A review. Montana Bureau of Mines Geology Special Publication, 73, pp. 53-72.

Fisk, L.H., 1976.  Paleoenvironmental interpretations of the Eocene "Fossil Forests" of Yellowstone National Park, Montana and Wyoming. 25th International Geological Congress, abstract. 1:303.

Fritz, W. J., 1980.  Reinterpretation of the depositional environment of the Yellowstone 'fossil forests'.   Geology, vol. 8, pp. 309-313.

Fisk, L.H., Aguirre M.R. and Fritz, W.J., 1978.   Additional conifers from the Eocene Amethyst Mountain "Fossil Forest," Yellowstone National Park, Wyoming. Rocky Mountain Section, Geological Society of America Meetings, abstract.

Fisk, L.H. and DeBord, P., 1974.  Palynology of the "Fossil Forest" of Yellowstone National Park, Wyoming. American Journal of Botany, abstract, 61, pp. 15-16.

Fisk, L.H. and DeBord, P., 1974.  Plant microfossils from the Yellowstone Fossil Forests: Preliminary Report. Geological Society of America, Abstracts with Programs, 6(5), pp. 441-442.

Fisk, L.H. and Fritz, W.J., 1984.   Pseudoborings in Petrified Wood from the Yellowstone "Fossil Forests." Journal Paleontology 58(1), pp. 58-62.

Fritts, H.C., 1976.  Tree rings and climate. Academic Press, London.

Fritz, W.J., 1977. Paleoecology of petrified woods from the Amethyst Mountain "Fossil Forest" Yellowstone National Park, Wyoming. Ph.D. Thesis, Walla Walla College, College Park, Washington. 57pp.

Fritz, W.J., 1980.  Reinterpretation of the depositional environment of the Yellowstone "fossil forests". Geology, v.8, pp. 309-313.

Fritz, W.J., 1982. Geology of the Lamar River Formation, northeast Yellowstone National Park. Pages 73-101 in M. Rucker and F. Drago, eds. Wyoming Geological Association Guidebook, Casper, Wyoming.

Fritz, W.J., 1984. The puzzle of Yellowstone's petrified forest. Montana Magazine, January-February, pp. 15-16.

Fritz, W.J., 1984.  Comment and Reply on "Yellowstone fossil forests: New evidence for burial in place." Geology, v.12, p.638-639.

Fritz, W. J., 1985.  Roadside Geology of the Yellowstone Country.  Mountain Press, 149 pp.

Fritz, W.J., 1986. Plant taphonomy in areas of explosive volcanism in land plants: Notes for a short course. T.W. Broadhead, ed. Department of Geological Sciences, University of Tennessee, Knoxville. Studies in Geology 15, pp.1-9.

Fritz, W.J. and Fisk, L.H., 1977.  Paleoecology of some Eocene woods from the Amethyst Mountain "Fossil Forest," Yellowstone National Park, Wyoming. Botanical Society of America Abstracts 154, p.37.

Fritz, W.J. and Fisk, L.H., 1978.  Eocene petrified woods from one unit of the Amethyst Mountain "fossil forest." Northwest Geology, 7, pp.10-19.

Fritz, W.J. and Fisk, L.H., 1979.  Paleoecology of petrified wood from the Amethyst Mountain "Fossil Forests," Yellowstone National Park, Wyoming. National Park Service Proceedings 5(2), pp. 743-749.

Holmes, R.L., Adams, R.K. and Fritts, H.C., 1986.  Tree-ring chronologies of western North America:

California, Eastern Oregon, and Northern Great Basin with procedures used in the chronology

development work including users manuals for computer programs COFECHA and ARSTAN. Laboratory

of Tree-Ring Research, University of Arizona, Tucson, AZ, Chronology Series VI.

Knowlton, F.H., 1895.  Fossil forests of Yellowstone National Park. The Epoch 1(1), pp. 15-50.

Knowlton, F.H., 1896.  The Tertiary floras of Yellowstone National Park. American Journal of Science, 4th Series 2, pp. 51-58.

Knowlton, F.H., 1898.  The standing fossil forests of the Yellowstone National Park. Plant World 1(4), pp. 53-55.

Knowlton, F.H., 1899.  Fossil flora of the Yellowstone National Park. U.S. Geological Survey Monograph 32, pp. 651-882.

Knowlton, F.H., 1914.  Fossil forests of the Yellowstone National Park. Department of the Interior, Office of the Secretary. 31pp.

Lugenbeal, M.P., 1968.  Evidence bearing on the time involved in the deposition of the fossil forests of the Specimen Creek area, Yellowstone National Park, Montana. M.A. Thesis, Andrews University, Michigan. 85pp.

Read, C.B., 1930.  Fossil floras of the Yellowstone National Park, Part 1, Coniferous woods of Lamar River flora. Carnegie Institute of Washington Publication 416, pp.1-19, 416-468.

Retallack, G., 1981.  Reinterpretation of the depositional environment of Yellowstone fossil forest: Comment. Geology, 9, pp. 52-53.

Ritland, J.H., 1968.  Fossil forests of Specimen Creek area, Yellowstone National Park, Montana. M.A. Thesis, Andrews University, Michigan. 62pp.

Smirnoff, L.,  and Connelly, W., 1980.  Axes of elongation of petrified stumps in growth postion as possible

indicators of paleosouth, Alaska Peninsula. Geology 8:547-548.

 

Tillman, S.E., 1893.  Fossil forests of the Yellowstone. Popular Science Monthly, 43, pp. 301-307.

Wheeler, E., 1993.  Fossil dicotyledonous woods of Yellowstone National Park, Wyoming. Pages 113-116 in V. Santucci, ed. National Park Service Paleontological Research Technical Report NPS/NRPEFO/NRTR-93/11.

Wheeler, E., 1995.  Systematic and ecologic significance of fossil hardwoods: Examples from Big Bend National Park, Yellowstone National Park, and Florissant Fossil Beds National Monument. Pages 113-117 in V. Santucci and L. McClelland, eds. National Park Service Paleontological Research Technical Report. NPS/NRPO/NRTR-95/16.

Wheeler, E., Scott, R.A. and Barghoorn, E.S., 1977. Fossil dicotyledonous woods from Yellowstone National Park Region. Journal Arnold Arboretum, 58, pp. 280-302.

 

Yamamoto, T. and Chadwick, A.V., 1982.  Identification of fossil wood from the Specimen Creek area of the Gallatin Petrified Forest, Yellowstone National Park. Part I. Gymnosperms. Journal San-iku Gakuin J C. 10, pp. 25-42

 

Young, P.A., 1935.  Petrified sequoia trees in the northwest corner of Yellowstone National Park. Research Report in Yellowstone National Park Archives. 4pp.

Yuretich, R.F., 1984. Yellowstone fossil forests: New evidence for burial in place. Geology, v.12, p.159-162.

Yuretich, R.F., 1984. Comment and Reply on "Yellowstone fossil forests: New evidence for burial in place." Geology, v.12, p.639.