Authors: David B. Williams
William Brown’s gas station, Lamar, Colorado.
For Brown, the station fit into his long-term role as a town booster.
He had sponsored Lamar’s first swimming pool, helped
start a chapter of Rotary International, and co-owned the first radio station.
He employed over a hundred people at his family’s
business, the Brown Lumber Company.
The gas station was a logical next step in drawing attention to Lamar.
The newspaper also
reported that Brown had purchased 480 acres of land around the petrified forest where he obtained his building supplies and
that he planned to develop the area as a tourist attraction.
No one, however, has located any record of Brown’s purchase of the land.
Eighty-one-year-old Lamar veterinarian Elmer Sniff
e-mailed me that Brown stole the wood from private property.
“My family made several Sunday afternoon trips to the ‘Petrified
Forest’ in the ‘Little Cedars,’ about twenty-five miles south of Lamar,” wrote Sniff.
“Our only admonition was to never take
any of the petrified wood and spoil the pristine nature of the area.
However, not everyone felt this way.” Several other Lamar
natives confirmed that Brown had not necessarily acquired his petrified wood via traditional, legal methods.
Ironically, Field
wrote in his cover story about the building that Brown built it because of the “added threat that these [petrified remains]
might be permanently lost to the region.”
“Petrified wood is the fossil for the common man,” says Kirk Johnson, a paleobotanist at the Denver Museum of Nature and Science.
2
In traveling around the American West, he has seen dozens and dozens of petrified logs in people’s yards.
“Some of the specimens
weigh hundreds of pounds.
I am amazed at the efforts people go to to haul this stuff back home,” he says.
“I think it’s because
they can relate to the wood as a living organism.
They can recognize it as a petrified tree.”
I observe people making the petrified wood–living tree connection often in my part-time job as an educator at the Burke Museum
of Nat ural History and Culture in Seattle.
As part of the teaching program, we give the students the opportunity to handle
a variety of fossils.
The only fossil that every child can identify is the piece of petrified wood.
The parent chaperones
also are able to recognize the fossil and they get more excited by a two-inch-diameter piece of petrified wood than by a four-inch-long
Tyrannosaurus rex
tooth.
No one can walk out of a museum and immediately see a dinosaur, whereas a museum visitor can walk outside and immediately
encounter a living tree that looks identical to the 100-million-year-old fossil tree she just encountered.
Recognition also applies in nonmuseum settings.
Most fossils one encounters in the field don’t look like a distinct life form
(and definitely not like they do in a museum) or if they do look somewhat recognizable, few people can identify the specimen
beyond calling it a bone or a shell.
In contrast, when someone finds petrified wood in the field, they are often able to recognize
it as a fossilized tree and not merely a fossilized something or another.
They can have a distinct sense of discovery, knowing
they have made a connection to the past.
It can be a profound moment, particularly if they have never found a fossil before.
Petrified wood has another advantage over most other fossils.
Drop that
T.
rex
tooth and it might break.
Drop a piece of petrified wood and it might hurt the floor or toe it hits but it will remain intact.
One of the most beautiful of fossils, petrified wood is displayed in photos in Frank J.
Daniels’s book
Petrified Wood: The World of Fossilized
Wood, Cones, Ferns, and Cycads
.
One strange specimen from Arizona has quartz-filled cracks that look like a star in a night sky.
A green and blue stump
from Oregon resembles a topographic map of rivers and forests, and a fiery red, yellow, orange, and blue log from Nevada seems
to glow from within.
On many of Daniels’s examples, the perfectly preserved annual tree rings allow you to determine precisely
how long the tree lived.
Unfortunately, people’s fascination with petrified wood often motivates them to break the law.
Rangers at Petrified Forest
National Park in Arizona estimate that visitors steal twenty-four thousand pounds of petrified wood per year.
Many scofflaws
argue that they don’t know they are breaking the law, despite the numerous signs telling them otherwise.
Some think that if
they don’t pick up the petrified wood, it will erode and be lost to science—still others take a more modern approach and blame
their parents, claiming that it is family tradition to collect petrified wood.
3
About a mile from the exits, rangers erected signs warning that cars are subject to inspection before leaving the park.
The
warning has had limited success, as each month, park employees collect just tens of pounds of petrified wood near the signs.
The park visitor center has a display of what rangers call “conscience letters” from people who were not caught during car
inspections but who later returned their purloined petrified wood.
Many letters refer to a curse.
People said they lost their
dogs, got flat tires, or had a death in the family because they had taken a piece of petrified wood.
The display has been
effective; follow-up interviews by park employees show that 80 percent of people who read the letters said they wouldn’t steal
wood— not because it was illegal but because of the potential bad luck.
One unexpected consequence, however, was that visitors
who read the letters sometimes stole a piece so they could send it back with a “witty letter,” in the hopes it would get posted
in the park’s display.
The park receives about six hundred pounds of returned petrified wood per year.
Clearly the curse is
only so effective.
Fossils such as petrified wood have long intrigued people.
“No greater objects of wonder have presented themselves to man’s
consideration than the fossils which from earliest times have been observed in different parts of the earth’s crust,” wrote
Lester Ward in his
Sketch of Paleobotany
.
4
And yet few understood how fossils formed until at least the late 1800s.
Prescientific ideas fall into three camps: by magic,
by seed, and by flood.
Many early natural philosophers did not consider fossils as the remains of once living beings.
Instead
fossils were
lusus naturae
, freaks of nature, which some latent planetary force (
vis plastica
) mystically created.
One sixteenth-century writer, George Agricola, attributed petrified wood formation to a stone juice,
succus lapidescens
.
The second camp was only slightly less mystical.
In 1699 Welsh naturalist Edward Lhuyd described “exhalations which are raised
out of the sea” carrying fish-spawn that got caught in chinks in the ground and became fish fossils, which “have so much excited
our admiration, and indeed baffled our reasoning.”
5
Lhuyd may not have had a clue about how fossils formed, but he has recently received credit for the earliest description
of a dinosaur fossil.
He, however, thought the dinosaur tooth was one of his vapor-produced, fauxfish teeth.
6
In the best case of a religious reformer masquerading as a scientist, Martin Luther popularized the idea that fossil plants
and animals developed from Noah’s flood.
He wrote in his
Lectures on Genesis
in 1535, “I have no doubt that there are remains of the Flood, because where there are now mines, there are commonly found
pieces of petrified wood.”
7
Although Luther’s diluvial theory took nearly a century to gain popularity, it influenced many scientists of the seventeenth
and eighteenth centuries, particularly Swiss paleobotanist Johann Scheuchzer, who reported that he had found the fossilized
remains of an eyewitness to Noah’s big adventure.
For those interested in seeing the infamous skeleton, named by Scheuchzer
Homo diluvii testis
, or human who witnessed the deluge, all you have to do is travel to Teylers Museum in the Netherlands, where you will learn
that Scheuchzer’s eyewitness was a giant salamander.
“This view [Luther’s] may seem to us a poor substitute even for the worthless dreams which had to make way for it, but when
philosophically viewed it will be seen that it was really a decided advance upon these,” wrote Ward.
8
Diluvialists may have been completely wrong about the Flood, but at least they acknowledged that fossils developed from formerly
living plants and animals that had turned to stone after the mud from the Flood covered those who missed the boat.
These early writers suffered because all of them lived before anyone had a remotely accurate age for Earth.
An origin in Noah’s
flood made sense in their minds because the planet was only six thousand years old and the only widely accepted big event
that could have killed and preserved so many plants and animals was the deluge.
Not until the 1800s did fossil collectors
consider a time on Earth before the Flood and before Adam and Eve.
Aided by the work of Lyell and Darwin, paleontologists
(the term first appeared around 1830) began to recognize that different plants and animals lived and died at different times
in the past.
By 1885, when Ward penned his
Sketch
, he could confidently reject the “puerile speculations” of old and rejoice in the “true advent of science.”
After recognizing the great age of fossils, paleontologists turned to another hallowed question pondered over the millennia
by fossil enthusiasts.
How did petrified wood form?
Agricola’s idea of a stone juice penetrating rocks and producing something
that looks like bone or wood may sound a bit too mystical but he was on the right track; petrified wood requires mineral-rich
groundwater in order to form.
First, the tree must get buried rapidly to prevent oxygen from reaching the wood.
Otherwise,
fungi consume the wood.
Burial that leads to wood preservation may occur via volcanic ash, which can preserve trees upright,
or via fluvially deposited mud, which can bury trees transported downriver.
Next, a petrifying agent must enter the wood.
At least forty different minerals have petrified wood, but the most common by
far is quartz, or silica.
Because quartz resists chemical and physical breakdown better than most other minerals, any tree
petrified by silica usually lasts longer than one preserved by calcite or pyrite, the next two most common minerals to petrify.
Other trace amounts of elements may also invade the wood and provide color, such as iron (red), manganese (blue to purple),
copper (green), and sulfur (yellow).
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A lack of oxygen does not mean a lack of life.
Bacteria in the wood aid the process of silification by creating acidic conditions
that lead to silica precipitating out of the water.
The silica accumulates on and in the wood’s cell walls, which act as a
template for growth.
Petrifaction continues as the woody walls deteriorate and more silica fills the voids, faithfully replicating
the tree’s internal structure.
This process of per-mineralization commonly occurs in the fossilization of many organisms.
The change from wood to stone straddles a fine line between deterioration and accumulation.
The wood has to break down slowly
enough to allow silica to penetrate and replicate the plant’s cell structure.
If deterioration occurs too quickly, the template
will disappear and no structure will remain.
If it occurs too slowly, no voids will form for silica accumulation.
“Organic
templating,” as geologists call this mode of preservation, contrasts with a common misconception that silica simply replaces
wood molecule by molecule.
In fact, most petrified wood still contains organic material, up to 5 percent by weight.
10
Experimental research has shown that petrifaction can occur very quickly.
A German physician wrote in the sixteenth century
that he had made wood as hard as flint in three years by cooking it in beer and burying it in his cellar.
Modern researchers
have also placed alder wood in hot springs and within seven years silica had permeated the wood.
Perhaps if Martin Luther
had conjectured that Noah had floated on a sea of hot beer, then we might believe the German theologian’s geologic observations.
Geologists reject a young age because of the instability of the silica that impregnates wood.
Under a microscope, quartz can
look either ordered and crystalline, known as agate or chalcedony, or amorphous and watery, known as opal.
The majority of
petrified wood under 65 million years old is opal, whereas older petrified wood is chalcedony.
Researchers account for this
difference because heat drives off water, consolidates the internal structure of silica, and converts opal to agate, a process
that normally takes millions of years.
Beauty comes to those who wait.