Not too long ago at a theme park not too far
away, Star Wars: Galaxy’s Edge opened at
Disneyland—and soon at Walt Disney World—transporting
people to Black Spire Outpost on the planet
of Batuu.
While the tall rock spires of Batuu enhance
the other-wordly experience, they take their
inspiration from some very real rocks here
on Earth.
In this video, I’m going to discuss the
geology that inspired the planet of Batuu
and Star Wars: Galaxy’s Edge.
The tall rock spires of Batuu are designed
to be giant petrified, or fossilized, trees.
Black Spire Outpost gains its name from the
135-feet-tall petrified spires of once giant
trees, one of which is a striking dark black
color.
As described by the Disney Parks Blog, “Widely
known for the petrified remains of its once
towering ancient trees, the spires now stand
guard across the river valleys and plains
and have long captured the imagination of
travelers to this planet.”
These petrified tree spires were largely inspired
by Petrified Forest National Park, located
in northeast Arizona.
Although at Petrified Forest National Park,
you won’t find anything visually reminiscent
of a forest or see any tall ancient tree spires.
The petrified trees here are all fallen logs
or stumps that have fragmented over time.
Around 215 million years ago, this area in
present day Arizona was a sub-tropical forest
with 200 foot-tall trees in a basin with flowing
rivers and streams.
Over time, trees would die and fall into the
streams, and some would become petrified,
or fossilized.
In order for an organism—either plant or
animal—to become a fossil, it first must
die and then be rapidly buried.
Upon death, most organisms decay or are subject
to scavengers, leaving no material or fossil
behind.
But rapid burial can cut off oxygen, slowing
or stopping decay and helping the preservation
potential.
The trees that became petrified here were
buried quickly and deeply in the sediment
of the ancient rivers, which inhibited decomposition.
Part of the petrification process—actually
becoming a fossilized tree—involves a step
call permineralization.
Permineralization is where minerals are deposited
in the cells of an organism.
In the case of these trees, silica dissolved
from volcanic ash was carried into the trees
through groundwater, forming quartz within
the tree’s cells.
The trees then underwent the final step in
petrification, replacement, where all organic
material was fully replaced by minerals like
quartz.
You’ll notice that the petrified trees are
various hues of red, orange, blue, and gray—this
is due to mineral impurities like carbon,
copper, and iron.
The full fossilization process can take up
to millions of years, although it can occur
more quickly.
Erosion over time then re-exposed the petrified
trees.
If you’d like to see a real petrified tree,
you don’t have to travel far!
Located in Frontierland near the Rivers of
America, you’ll find the remains of a real
petrified tree.
Gifted to Disneyland by Lillian Disney in
1957, this petrified tree stump comes from
the Florissant Fossil Beds National Monument
in Colorado and was likely once part of a
200-foot-tall tree.
The plaque by the tree, unfortunately, does
not have the most accurate geological explanation
for its origins, stating that it formed “55
to 70 million years ago” and that “During
some prehistoric era a cataclysmic upheaval
caused silica laden water to overspread the
living forest.”
In reality, this tree was part of a forest
35 million-years-ago, and we can thank its
preservation primarily to explosive volcanic
eruptions.
At the time, nearby volcanoes spewed out loose
ash and debris onto their flanks.
When intense rainfall mixes with this loose
volcanic material, it can create extremely
fast-moving and deadly mudflows called lahars.
A lahar mudflow was triggered and traveled
from the flanks of the volcano toward the
forest valley, rapidly depositing muddy ashy
material, which trapped the tree trunks in
place, killing them and cutting them off from
oxygen.
The trees were then petrified when dissolved
silica derived from the volcanic ash precipitated
into the wood cells and the organic material
became fully replaced by quartz.
So all in one trip to Disneyland you can explore
Earthly and other-worldly petrified trees!
If I had to imagine how the massive petrified
tree spires of Batuu came to be, I could picture
there being massive volcanic eruptions millions
of years ago that buried the giant trees in
over a hundred feet of ash.
Huge volcanic eruptions with pyroclastic flows
and lahars could destroy an entire forest.
Many of the petrified spires appear to be
in situ—meaning in place—so they appear
to have been fossilized right where they grew.
Some trees in the Resistance Forest area do
appear to have fallen over and were later
buried and fossilized, like the trees of the
Petrified Forest National Park.
Volcanic ash is compacted into a rock called
tuff, which would encase the trees spires
as they petrified over time.
How might one spire become so much blacker
than the others?
It could have taken in a lot of carbon impurities
during petrification, which would have led
to a dark black color.
The area would have to experience large amounts
of erosion to erode away much of the tuff
and expose the hardened petrified spires.
You can even see relict dwellings carvings
in the rock, much like the pueblos carved
into the tuff at Bandelier National Monument
in New Mexico.
Next time you travel to Batuu, you’ll now
be an expert in the origins of the spires
that give Black Spire Outpost its name, and
know about the Earthly counterparts that inspired
them.
May the spires keep you!
