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Petrified National Forest

April 7, 2017

Thanks to Alissa Simon, HMU Tutor, for today's post.

“It is only by becoming sensible of our natural disadvantages that we shall be roused to exertion, and prompted to seek out opportunities of discovering the operations now in progress, such as do not present themselves readily to view.” - Charles Lyell

Charles Lyell first published the Principles of Geology in 1830. However, over the next thirty years, he continued to edit and revise his Principles until he published a final two-volume work in 1867-8. This work is a beautiful treatise on understanding changes that have affected and continue to affect the earth. In it, Lyell defines principles necessary for the scientific study of geology, while at the same time, he refutes common myths and stereotypes which previously inhibited the study of the earth. This gigantic work was written with the input of years of experience and conversation with other scientists, including his friend Charles Darwin.

On a recent stop in Petrified National Forest, I found some of Lyell's conversation repeating in my mind. Particularly, the idea that one can travel to a distant land without ever having left the earth, and without ever having left your home. In other words, Lyell's ability to see geologic structures as a mixture of age and processes enlivened the rocks about me as if a literal experience of time travel.

Photo credit: Alissa Simon

Photo credit: Alissa Simon

The fact that trees of such height and width once existed in the seemingly barren terrain of Petrified Forest demands imagination. Instead of a desert, this land used to be filled with water, rivers, swamps and animals. When these mythic, large trees fell, they landed deep in the rivers and swamps and absorbed sediment which caused them to solidify. Merriam-Webster defines “petrified” as: “to convert (organic) matter into stone or a substance of stony hardness by the infiltration of water and the deposition of dissolved mineral matter.” In other words, the processes acting upon these trees literally changed their composition from wood to stone. They are massive, dense and heavy. They break by their own weight when the sediment supporting a portion of one log erodes. The log, then, fractures like a bone, sticking oddly and forlornly out of the earth. Their interior rings represent more than the age of the tree, but the age of the location, the age of the earth in which they lay and a colorful map of organic matter. This log which looks like a tree stump does not act like one. Instead, they are filled with spectacular colors of various sediments. Light reflects through them, and they no longer show signs of fibrous content. Upon investigation and imagination, one has literally traveled millions of years.

Photo credit: Alissa Simon

Photo credit: Alissa Simon

The riverbeds in which they lay are now dry dustbeds, which receive violent, but sporadic rainfall. The desert here appears gray, blue, purple, pink and rusty. Somehow, plants eke out an existence. And where there are plants, there will be insects. Where there are insects, there will be lizards and birds. And with these follow larger predators. I imagine it is a very difficult life. But I also imagine that sunsets enliven these pronounced vistas with color unimaginable. And then, there are the fossils and ancient writings. Petrified National Forest offers a wide variety of interests for those wandering along Interstate 40. If nothing else, stop just to take in the views.

For more information, visit: https://www.nps.gov/pefo/index.htm .

Watch a short video about the park: https://www.youtube.com/watch?v=068GcVD3VaE

“The adoption of the same generic, and, in some cases, even the same specific names for the exuviae of fossil animals, and their living analogues, was an important step towards familiarizing the mind with the idea of the identity and unity of the system in distant eras. It was an acknowledgement, as it were, that a considerable part of the ancient memorials of nature were written in a living language. The growing importance then of the natural history of organic remains, and its general application to geology, may be pointed out as the characteristic feature of the progress of the science during the present century. This branch of knowledge has already become an instrument of great power in the discovery of truths in geology, and is continuing daily to unfold new data for grand and enlarged views respecting the former changes of the earth.” - Charles Lyell

“But if, instead of vague conjectures as to what might have been the state of the planet at the era of its creation, we fix our thoughts steadily on the connection at present between climate and the distribution of land and sea; and if we then consider what influence the former fluctuations in the physical geography of the earth must have had on superficial temperature, we may perhaps approximate to a true theory.” - Charles Lyell

“[T]he geologist is in danger of drawing a contrary inference, because he has the power of passing rapidly from the events of one period to those of another – of beholding, at one glance, the effects of causes which may have happened at intervals of time incalculably remote, and during which, nevertheless, no local circumstances may have occurred to mark that there is a great chasm in the chronological series of nature's archives.” - Charles Lyell

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