Paleontology of Disney - Disneyland's Petrified Tree

 

Disneyland's Petrified Tree

Unlike most of the dinosaurs and other geological features we see in most of the Disney parks, in Disneyland there is an actual fossil. This is the "Petrified Tree" in Frontierland.

Gifted to Lillian Disney on their 31st wedding anniversary by Walt, this petrified tree stump was purchase by Walt on a tour of the American west. And, as is with most anniversary gifts, Lillian just couldn't find a place for it in their house, so she ended up donating it to Disneyland as an exhibit, where it still stands today.

The Petrified Tree stump has two plaques on it that read the same thing. These state:

Petrified Tree  

from the 

Pike Petrified Forest, Colorado. 

This section weighs five tons and measures 7 1/2 feet in diameter. The original tree, estimated to have been 200 feet tall, was part of a sub-tropical forest 55 to 70 million years ago in what is now Colorado. Scientists believe it to be of the redwood of sequoia species. During some prehistoric era a cataclysmic upheaval caused silica laden water to overspread the living forest. Wood cells were changed during the course of time to sandstone. Opals were formed within the tree trunk itself. 

Presented to Disneyland 

by 

Mrs. Walt Disney 

September 1957. 

I love that they include some geology and paleontology in the description for the fossil. However, a bit of it is wrong and some of it is outdated. While at the time, the tree stump was purchased from Pike Petrified Forest, this area is now in a National Park! It is actually Florissant Fossil Beds National Monument. And while taking (and buying) fossils from National Park property is very illegal, this occurred before the National Park was established, and was therefore ok at the time. 

Stratigraphic section from where the tree stump was originally found (as noted by the stump in the section) from Florissant Fossil Beds NM. Image courtesy of Meyer et al., 2004.

The age of the petrified tree stump is also incorrect. On the plaque they note it is was part of a forest "55 to 70 million years ago", however scientists have since dated the sediments from which the trees were formed in and it turns out they are far younger, ~34 million years old. 

While there is much wrong and/or outdated on the plaque, there is information that is correct. These are indeed sequoia tree stumps and they were indeed silicified during "some prehistoric era ... cataclysmic upheaval [which] caused silica laden water to overspread the living forest". However, the tree itself was not turned into "sandstone", since there is no "sand" associated with it at all, they would just be denoted as "petrified wood" or "fossilized wood". 

Map of the impact area for the Guffey volcanic center. Image courtesy of Colorado Stories.

The Disneyland tree stump grew in a forest within ~18 miles an area known as the Guffey volcanic center within the Thirtynine Mile volcanic center. Eruptions from this volcano complex are the ones that produced pyroclastic debris (ash, pumice, hot rock, boiling hot air, and lots of nasty stuff) along with lahars (boiling hot mudflows mixed with more ash and other nasty stuff) that blanketed the region. These lahars blocked off the drainage and eventually created what is known as Lake Florissant. 

Within Lake Florissant, mudstones and other volcanic eruptive materials were deposited forming the Florissant Formation, in which the stumps are preserved. One of those volcanic eruptions produced a lahar that killed the trees and blanketed the tree stumps, preserving them in a matrix of ash, pumice, and mud. The hot ash and other volcanic eruptive material, which is mostly made of silica, caused the water to become silica rich. These silica rich waters flowed around and through the tree stumps, prompting growth of diatoms (tiny animals with silica tests (shells) which mixed with the ash-mud, preserving the stumps and protecting them from degradation. Over time the stumps themselves were inundated with the silica rich waters, where the silica molecules replaced the wood molecules, turning them into the petrified wood that we see today (both in the National Park and at Disneyland.  

References

Meyer, Herbert W., Steven W. Veatch, and Amanda Cook. "Field guide to the paleontology and volcanic setting of the Florissant fossil beds, Colorado." (2004).

Wright, Alex. The Imagineering Field Guide to the Magic Kingdom at Walt Disney World: An Imagineer's-eye Tour. Disney Editions, 2005.

Sturmer, D.M., Vice, G.S., Sumida, S., and Mary, M., 2024, How geology and paleontology help build the magic of the Disneyland Resort (Anaheim, California, USA), in Van Buer, N.J., and Schwartz, J.J., eds., From Coastal Geomorphology to Magmatism: Guides to GSA Connects 2024 Field Trips in Southern California and Beyond: Geological Society of America Field Guide 70, p. 27–44, https://doi.org/10.1130/2024.0070(02)

https://coloradostories.online/f/in-search-of-the-mighty-redwood-stumps-in-florissant-colorado