A Florissant Fossil for the White City

 

by

Steven Wade Veatch

 The “Big Stump” at Florissant Fossil Beds National Monument, Colorado is one of the larger petrified stumps exposed in the Monument: it measures 3.6 meters tall and is 3.7 meters in diameter at breast height (Meyer, 2003). This solitary petrified stump is all that remains of a tree that was more than 60 meters tall when a volcanic mudflow (lahar) buried its base during the late Eocene.

Figure 1. This postcard, ca. 1894, shows a wooden framework
built around Big Stump. From the E. Simmons collection.

Big Stump is similar to the modern Sequoia (redwood) and is the type specimen described by Andrews in 1936 for Sequoioxylon pearsallii. An often-confusing aspect of paleobotany is that different organs (e.g., wood and leaves) that belong to the same living species are sometimes preserved isolated and unattached, in the fossil record. Therefore, it can be difficult to prove that they belonged to the same living species. For that reason they are sometimes given different names as fossils. At Florissant, Sequoioxylon pearsallii is the name assigned to the fossil wood and Sequoia affinis is the name for cones and foliage. They likely belonged to the same species of tree when they were living, but this cannot be proven unless these organs can be found attached in the same fossil. Philosophies differ, however, and in 1953 MacGinitie placed Sequoioxylon pearsallii into synonymy with Sequoia affinis. (Synonymy in the fossil record refers to the situation where two or more scientific names have been applied to the same fossil taxon.)

The Big Stump has been depicted in early photographs and postcards that date back to the late 1890s. Geologist Arthur Lakes, on an early expedition to the area with paleontologist Samuel Scudder, marked the location of a "petrified forest" on his original watercolor map in 1878—the general area where Big Stump is situated.

Figure 2. A broken and rusted saw blade remains wedged
in Big Stump from an attempt to cut it into sections and ship it to
Chicago for the World’s Fair. Image date 2003 by S. Veatch.

There was once a local effort to send this incredible fossilized tree stump to the World's Columbian Exposition (The Chicago World's Fair) of 1893. A plan was made in 1890 to remove the stump, transport it to Chicago by rail, and then rebuild it at the fair. Fortunately, the attempt to remove Colorado's prized fossil was unsuccessful. As it happened, the workmen’s saw blades became permanently wedged in the fossil wood. The plans to send Florissant’s famous stump to the Columbian Exposition were then quickly abandoned.

The World’s Columbian Exposition, one of the greatest cultural events of the nineteenth century, was named in honor of Christopher Columbus and celebrated the 400th anniversary of his arrival in the New World.

Figure 3. This ticket admitted the bearer into the World’s Columbian Exposition
in Chicago, a landmark event in American history and culture.
From the Michele Veatch Collection. 

Thousands were employed in the development of 633 acres of fairgrounds and the construction of 200 buildings in Chicago’s Jackson Park. Many of the fair buildings were located along constructed waterways fed by Lake Michigan. The Court of Honor buildings (14 main buildings) were covered in white stucco. Visitors, after seeing these white buildings, began to call this the White City. After three years of planning and building, and at a cost of twenty-eight million dollars, President Cleveland opened the fair on May 1, 1893. Ticket prices were 50 cents for adults and 25 cents for children.

Visitors to the Columbian Exposition enjoyed more than 65,000 exhibits and attractions. The fair contained many marvels and introduced Americans and the world to picture postcards, carbonated soda, hamburgers, and a gigantic wheel (built by George W. Ferris Jr.) that visitors could ride. The fair also introduced the nation to the Pledge of Allegiance and a new holiday—Columbus Day.

Figure 4. View of the Colorado building at the
World’s Columbian Exposition. Stacks of petrified wood
appear to be on either side of the entrance
to this building. Photo from the Michele Veatch Collection.

Most of the states and territories had exhibits at the fair, including Colorado. The Colorado building had a wide variety of displays from the Centennial State. If Big Stump had been cut and quarried into sections, the Colorado building would have been a likely destination. Colorado Day was celebrated September 12 at the fair without Big Stump—Colorado’s famous fossil remained at the Florissant Fossil Beds, intact. Although Big Stump did not make it to the Columbian Exposition, other Colorado fossils probably made it to the fair, perhaps even fossils from Florissant. (See note below.)

Figure 5. Fortunately, Big Stump did not make it to the
White City but remains for visitors to the Monument
to enjoy. Image date 2003 by S. Veatch.

By its closing date on October 30, 1893, more than 27 million people had visited the White City. If Big Stump had been removed and displayed at the fair, this oddity of nature would have been lost. This magnificent fossil is now protected by the National Park Service, and visitors to the Florissant Fossil Beds National Monument can view Big Stump in its geologic setting.

 Note: Some photos of the Colorado building depict stacks of petrified wood by the entrance. Because the Big Stump didn’t reach the Columbian Exhibition, I think this petrified wood is from Florissant. I contacted the Field Museum to see if they still had some of this petrified wood. The Earth science curator said they had some unidentified petrified wood in the basement. I went to the Field Museum, met the curator, and examined this petrified wood. It was not fossil wood from Florissant. The origin of this wood in the museum’s basement is unknown. The wood in old photos of the Colorado Building might have come from Florissant and is no longer at the museum. We may never really know what became of the fossil wood in the photos or where it originally came from.

Acknowledgements

            I thank Bob Carnein for improving this manuscript. I also benefited from many discussions of the Big Stump with park ranger Jeff Wolin. I dedicate this article to him.

References and further reading:

Andrews, H.N., 1936. A new Sequoioxylon from Florissant, Colorado. Annals of the Missouri Botanical Garden 23 (3): 439-446.

MacGinitie, H.D. 1953. Fossil Plants of the Florissant Beds, Colorado. Carnegie Institution of Washington Publication 599:1-198.

Meyer, H.W., 2003. The Fossils of Florissant, Smithsonian Books, Washington, D.C., 258 p.

 

 

Florissant’s Sequoias: Redwood Giants of the Eocene

During the late Eocene large Sequoia (redwood) trees grew on terraces along an ancient river valley near present-day Florissant. Among these trees was the extinct Sequoia affinis, closely related to the modern redwoods (Sequoia sempervirens) that are now restricted to a narrow coastal region in northern Californa.


The “Big Stump” is one of the largest petrified redwood stumps exposed in
the Monument.  It measures 3.6 m tall and is 3.7 m in diameter at breast height. 
This stump is all that remains of a tree that was more than 90 m tall
when the mudflow buried its base.  Image date Nov 2003 by S. Veatch.

 More than 34 million years ago a lahar or volcanic mudflow, coming from a nearby volcanic center, flowed into the Florissant valley. The mudflow was up to 5 meters deep and quickly surrounded these giant trees. The upper section of the redwoods decayed and rotted away while the lower 5 meters were protected by the silica-rich mudflow. The unhurried progression of petrification—through a process known as permineralization—preserved the remains of these ancient trees with incredible detail, including tree rings.

Tree rings, which record annual growth, also reveal the growing conditions of trees. A researcher at the Florissant Fossil Beds National Monument carefully measured tree rings in fossil wood (Sequoioxylon pearsallii) and noted a larger (40%) average tree-ring width than the modern redwoods (Sequoia sempervirens) and giant Sequoia (Sequoiadendron giganteum) growing along the northern California coast. The significant difference in mean ring width between modern and extinct redwoods suggests the ancient redwoods in the Florissant Valley were growing under more favorable conditions than their modern counterparts.
It is thought that there was more precipitation, from moist Pacific Ocean air,that reached the western interior as the Sierra Nevada mountains of California had not yet been uplifted to block the flow of moist air. More precipitation, resulting from these moist air masses, would have fallen during the growing season.

Precipitation at Florissant during the late Eocene is estimated at about 50 – 80 centimeters of annual rainfall, greater than the modern precipitation of 38 centimeters. A higher level of atmospheric CO2, perhaps twice that of modern levels, may have contributed to the favorable growing conditions in the Florissant Valley of the late Eocene.

A subsequent volcanic mudflow moved across the ancient paleovalley, forming a dam of mud, rocks, boulders, and associated debris. A stream, running over earlier mudflows, began to back up behind the mud dam, eventually forming a large lake—Lake Florissant. Leaf and insect fossils were preserved in this lake.

Not only are the Sequoia stumps preserved, but Sequoia cones and foliage are also represented in the fossil record at Florissant. The cones and foliage are found separated from the tree, and have a separate classification from the fossil wood. Sequoia affinis cones are found as fossils in the thinly bedded shales of ancient Lake Florissant. The ovoid cones are made of spirally arranged scales and tend to be smaller (about two-thirds the size) than the modern coast redwood cones.

Fossil branches of the Florissant redwood, Sequoia affinis. 

Specimen FLFO-4858 from the collection of Florissant Fossil Beds National Monument. 

Image date Oct 2003 by S. Veatch.

Sequoia affinis cones. Specimen FLFO-4717 from

the collection of Florissant Fossil Beds National Monument. 

Image date Oct 2003 by S. Veatch.