Monday, November 02, 2026

Geology of the National Parks in Pictures - Statue of Liberty National Monument

My next post about the Geology of the National Parks Through Pictures is from the first half of the Statue of Liberty National Monument. The park is essentially two main parts, the first is the Statue of Liberty, and the second is Ellis Island. And since they are really their own entities, I will treat them separately. 


You can find more Geology of the National Parks Through Pictures as well as my Geological State Symbols Across America series at my website Dinojim.com.

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Statue of Liberty National Monument


Obligatory entrance sign


The Statue of Liberty sits on Liberty Island within the Upper New York Bay near the confluence of the Hudson River and the East River. There are actually numerous geological features for the Statue of Liberty as well as Liberty Island itself. Starting from the ground up, let us look Liberty Island itself.

Bedrock Geology Map of Liberty and Ellis Islands (Volkert, 2016).

The bedrock of Liberty Island is made up entirely of what is labeled as OCh on the Geological Map above. This is the Middle Cambrian to Middle Ordovician age (~510 to 460 million years old) Hartland Formation (per the map key). The Hartland Formation is one of the two primary metamorphic rocks that make up the basement rocks of NYC. It underlies most of the western part and southern half of Manhattan and the eastern Bronx, as well as the islands within the New York Bay and into parts of New Jersey. 


The Hartland Formation was originally a sedimentary rock that was deposited in the deep ocean, in an area surrounded by volcanoes. These volcanoes would occasionally introduce volcanic sediment into the basin mixed with other sources of sediment that added sand and clay. These sediments were then metamorphosed when North America ran into some off shore volcanic islands. This collision initiated the formation of the Appalachian Mountains, a period of time known as the Taconic Orogeny. 

Surficial Geology Map of Liberty and Ellis Islands (Stanford, 1995)

On top of the bedrock sits what is known as surficial deposits. Many areas of New York, like notably Long Island, have large amounts of glacial debris sitting on top of the bedrock. Liberty Island, however, does not appear to have glacial debris. On the Surficial Geology map above, the surficial deposits are  labeled as Qbn, which represents Deltaic Deposits. These are sediments that are deposited at the end of a river system, which is a mixture of rocks from further up river. These likely are related to being located at the headwaters of the Hudson and East Rivers. 


Moving upwards from Liberty Island, we can take a look at the Statue of Liberty herself, or more specifically, the pedestal for the statues. The pedestal for the statue is largely made up of concrete, as it would need to support the weight of the statue. However, there is a granitic facade meant to "pretty up" the statue. 


When you look downwards on the statue though, you can see that the lower base is arrayed in a star shape. This is because this was a pre-existing structure already on Liberty Island, a military fort known as Fort Wood. Most of the fort was converted and filled with concrete in order to support the statue. You can see remnants of the forts in various places across the lower foundation.


After the foundation was constructed within the fort, and then built up to form the pedestal for the statue, the concrete surface was then adorned with this lovely pink granite. The pink granite stones were purchased from Beattie Quarry (also known as the Leete Island Quarry) in Guilford, Connecticut, which was owned and operated by Scottish immigrant John Beattie. Stones from this quarry were used on other monuments and buildings such as Grant's Tomb (another National Park), the George Washington Bridge in New York City, the Battle Monument at West Point, and the museum buildings of the Smithsonian Institution in DC.


The name of this granite goes by a few names including the Leete Island Granite, Stony Creek Granite, and Stony Creek Gneiss, but geologically it seems that Stony Creek Granite is the primary name. The area where this granite is found in Connecticut has several different types of granite deposits that all flow into one another. These are dependent on the source rock and the degree of metamorphism which altered some of the granites into the metamorphic rock gneiss. The Stony Creek Granite can be described as a pink granite with medium to very coarsely grained, comprised of the minerals oligoclase, K-feldspar, and quartz with minor biotite, magnetite, garnet, and muscovite. The Stony Creek Granite formed roughly 600 million years ago, during the Proterozoic during another mountain building event known as the Avalonian Orogeny. The Avalonian Orogeny formed the Avalon Platform of Newfoundland, however effects of that mountain building event extended down into New England. During this time there was lots of magma that rose up towards the surface and cooled slowly underneath the ground to form the core granitic bodies. Over time these granites were partially metamorphosed to create the patches of gneisses. 


Moving our way upwards, we get to the Statue of Liberty herself, focusing on the geology of her copper coating. The Statue of Liberty contains 176,000 pounds of copper that is hammered out to a thickness of 3/32 of an inch, which is the thickness of 2 copper pennies placed together. It is generally thought that the source of the copper is from the copper mines of Visnes at Karmoy, a small rocky island near Stavanger in Norway. These mines were owned by France at the time of the statue's construction, however that alone wasn't evidence enough to link the two. That is when a metallurgical analysis of the copper by Bell Labs confirmed that the impurities within the Statue of Liberty's copper matched those in the Visnes mines, indicating a likely match. 

Looking up the stairs towards the crown, off limits when we were there. 

The rock unit the copper came from is known as the Karmøy ophiolite, an Early Ordovician (~480 million years old) rock that formed as part of the sub-floor of the ocean. An ophiolite is a geological term for part of the oceanic crust that is brought up onto land. Part of this ophiolite complex contains what is known as the Visnes massive Fc-Cu-Zn sulfide deposit, where the copper used in the Statue of Liberty was found. This copper deposit was formed when basaltic rocks in the sub-sea floor were altered by the presence of magma-influenced hydrothermal fluids. This is the way a lot of copper deposits are formed, when you have a magma body heating up the ground waters and enriching them with metallic and other elements common in magmatic bodies but not common in sedimentary environments. 


The final geological process is more of a chemical process, and that is the conversion of the copper colored copper to the green that we know the Statue of Liberty to be. While this is mostly a chemistry aspect, we can address it here as well. The answer is oxidation, also known as rust, however in copper the process is also known as patination. The oxidation process where iron is turned red by the addition of oxygen to form rust is a similar process for copper. The copper molecules combine with the oxygen to form a green patina crust to the copper plating. When originally constructed, the statue was actually the copper color of a new penny.  

References
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Monday, October 26, 2026

Geology in Pop Culture - Volcanoes Part 2: The Scream

 

Volcanos Part 1: The Scream 

(AKA the influence of volcanic eruptions)


Volcanic eruptions have had many pop-culture influences over the years including influencing art, literature, and even music. We are going to look at three notable instances. These include Mary Shelley's Frankenstein published in 1818, Edvard Munch's painting The Scream from 1893, and Antonio Stradivari violins of the 1600's and 1700's.  

Edvard Munch's The Scream (1893)

 Edvard Munch, The Scream, 1893, Nasjonalmuseet, Oslo, Norway

Edvard Munch was a Norwegian artist, living in Norway at the time. In his diary entry of January 22, 1892, Munch had described his inspiration for The Scream:
One evening I was walking along a path, the city was on one side and the fjord below. I felt tired and ill. I stopped and looked out over the fjord—the sun was setting, and the clouds turning blood red. I sensed a scream passing through nature; it seemed to me that I heard the scream. I painted this picture, painted the clouds as actual blood. The color shrieked. This became The Scream.
There is also a poem that he had written from 1895 with much the same vibe (Daily Art Magazine):
I was walking along the road with two friends – the sun was setting – suddenly the sky turned blood red – I paused, feeling exhausted, and leaned on the fence – there was blood and tongues of fire above the blue-black fjord and the city – my friends walked on, and I stood there trembling with anxiety – and I sensed an infinite scream passing through nature.
There is no set time when this happened though, except that it must have been before the 1892 journal entry. It has been postulated (Olson et al., 2004) that the cause of this "blood red" sunset was from the eruption of the volcano Krakatoa in Indonesia on August 27th, 1883. 

And while the eruption of Krakatoa was literally half a world away, there are other instances where the eruption impacted sunsets across the globe. There is a report in Pennsylvania from the Hanover Spectator from December 19th of 1883 where it is reported:
Residents “… witnessed a most beautiful and startling phenomenon … the sky … was fairly aglow with crimson and golden fires.”
Mount Krakatoa. Image courtesy of the Global Volcanism Project. 

Krakatoa (or Mount Krakatoa) is a stratovolcano located within the Pacific Ring of Fire and produced one of the largest eruptions in recorded history. 

During the eruption, ash was sent 50 miles into the atmosphere covering 300,000 square miles. The final eruption produced a shockwave that was heard by 10% of the Earth's surface and ejected as much as 5 cubic miles of rock fragments into the air, causing the island to collapse down into its 3.8 mile wide caldera. In addition, pyroclastic flows were produced, clouds of hot dust and ash of more than 300 degrees Celsius traveling at over 100 kph, wiping out everything for miles around the volcano. And the most devastation was produced by the series of tsunamis that smashed into 165 coastal villages in the surrounding islands of Java and Sumatra, extending to the Arabian peninsula, killing 36,000 people. The ash eventually circled the globe dropping the global temperature by a full degree Celsius the year following the eruption. It took 5 years for the Earth's temperature to revert to normal. 

It seems like based on Munch's personal accounts of the blood red sunset and the cause of that sunset, that it was indeed possible that the eruption was the impetus for the creation of The Scream.


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Tuesday, October 13, 2026

Geology in Pop Culture - Volcanoes Part 1: Frankenstein

Volcanos Part 1: Frankenstein 

(AKA the influence of volcanic eruptions)


Volcanic eruptions have had many pop-culture influences over the years including influencing art, literature, and even music. We are going to look at three notable instances. These include Mary Shelley's Frankenstein published in 1818, Edvard Munch's painting The Scream from 1893, and Antonio Stradivari violins of the 1600's and 1700's. 

Mary Shelley's Frankenstein or the Modern Prometheus (1818)


On April 5th of 1815, the Indonesian volcano, Mount Tambora began to erupt. While the eruption was huge on any scale, killing an estimated 10,000 people in proximity to the mountain, and many more beyond, the amount of material that was erupted managed to encircle the globe, blocked out the sun, and created the "year without a summer" in 1816. 

Location of Mount Tambora in Indonesia. Image courtesy of the Global Volcanism Program. 

Mount Tambora is a stratovolcano located on Sumbawa Island within Indonesia. The April eruption, which ended up lasting for months, produced pyroclastic flows that reached the seas on all sides of the peninsula. The total amount of material erupted eventually exceeded 150 cubic km of tephra (gasses, dust, and rocks that make up the volcanic material). On the volcano itself, after the eruption the top of the volcano collapsed into a caldera 6 km wide and 1250 meters deep. 

The Volcanic Explosivity Index (VEI) scale. Image courtesy of the USGS.

Volcanic eruptions are ranked in size by a VEI scale, "Volcanic Explosivity Index", with this eruption ranking a 7, the largest volcanic eruption in recorded history. While there is evidence of larger eruptions in the geological record, there are none that have been witnessed in the last few thousand years. This eruption was so loud, that it was heard over 1200 miles (1930 km) away. 

Map of temperature anomalies in Celsius across Europe during the summer of 1816 as compared to 1971-2000 climate normals. Image courtesy of UCAR Center for Science Education. 

The eruption was so large that it was able to inject a cloud the size of Australia of aerosolized volcanic debris into the atmosphere, blocking solar radiation and absorbing heat, producing a drop in global temperatures from 2 to 7 degrees F. This caused snow falls in summer and frosts that killed off crops, leading to an Irish famine, and locked people indoors for months. On July 4th, 1816, John Quincy Adams laments that he was confined to his house in London all day due to freezing rain showers and thunder. 

Tambora: The Eruption that Changed the World

Gillen D'Arcy Wood, in his book Tambora: The Eruption that Changed the World, laid out how this eruption influenced events that extend far into the 20th century. One such instance is that because of the terrible weather during the summer of 1816, Mary Shelley was locked indoors at the villa of Lord Byron on Lake Geneva, Switzerland. With her, was her husband, Percy Shelley and Lord Byron. Because of the lack of things to do, and the gloomy atmosphere outside, Lord Byron proposed a contest. Who could write the scariest ghost story. At the end of the contest, Mary, only 18 at the time, had constructed what is considered to be one of the greatest works of Gothic horror. And much to the surprise of no one, didn't win the competition, with Byron giving the victory to Percy, since Mary's work was considered "too philosophical".  

References

Wood, Gillen D’Arcy. Tambora: the eruption that changed the world. Princeton University Press, 2026.
Shelley, Mary. Frankenstein; or, The Modern Prometheus. Lackington, Hughes, Harding, Mavor, & Jones, 1818

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Monday, October 05, 2026

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
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
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Monday, September 28, 2026

Geology in Pop Culture - Taylor Swift's "Opalite"

Taylor Swift's "Opalite"

Released on October 3rd, of 2025 on The Life of a Showgirl album, "Opalite" is the third track on the album and was later released as a single on January 12th, 2026. 

Discussing the album on The Tonight Show Starring Jimmy Fallon, Taylor Swift breaks down the meaning of the song and where the name came from. In the interview she mentions a few geologically related items:

  • Opalite is man-made opal
  • Similar to how diamonds can also be man-made
  • Gemstones are mentioned in the chorus like "onyx night" 
She also makes note that the purpose of choosing "opalite" is that life is not always going to give you what you want and you are not always going to get your way. Sometimes you have to make your own happiness, like making an opal.

What is an Opal?

Let's break down the geology into bits and pieces. First, what is an opal and how is it formed?

Per the Dictionary of Geological Terms (3rd ed):

Opal: A mineral or mineral gel, SiO2 • n H2O. It has been shown by electron diffraction to consist of packed spheres of silica; water content is usually 3 to 9%. Opal occurs in most colors, is transparent to nearly opaque, and commonly exhibits a marked play of color. It is deposited at low temperatures and is found in a wide variety of rocks and forms. The transparent colored varieties showing opalescence are valued as gemstones. 

 Opalescence: A milky or somewhat pearly appearance or luster of a mineral, such as that shown by opal and moonstone.  

Crystal boulder opal, courtesy of Opal Galaxy

Natural opals are known for that pearly appearance, such as in the sample above, hence the term for the appearance is opalescence. Their formation is also super unique. Instead of forming molecule by molecule, slowing building up as a crystal, opals forms by the amalgamation of little spheres of silica. Because of this type of formation, opal is not actually classified as a mineral, but a mineraloid. Minerals, by definition, must have a definitive crystal structure, which opals do not. 

SEM Photograph of Opal spheres. Image courtesy of Sechrist et al, 2006.

It is because of these tiny spheres, and the way that they are organized, that opals diffract the light the way they do. The size and spacing of the spheres is what determines the color patterns that are seen. 
Diagram showing the formation of Australian opals. Image courtesy of Opal Galaxy. 

Looking at the geological formation of opals, there are two methods that have produced widespread opals in the geological record. Over 95% of opals in the world are found in Australia. These opals began to form around 100 million years ago during the Cretaceous. At that time Australia was covered by a vast sea, the Great Artesian Basin . 

Opal mining locations within the Great Artesian Basin. Image courtesy of Dans Opals.

Over time the sea slowly evaporated and left behind silica deposits. This silica was transported by groundwater into gaps within the underlying sandstone, ironstone, fossils, and ancient wood and precipitated in those spaces. This occurred over very low temperatures and took a long time, resulting in a stable, non-porous structure, of the opals that formed. These opals formed the opal deposits of Lightning Ridge, Coober Pedy, and the Queensland boulder regions. The slow creep of the groundwater is what allowed the orderly, grid-like, construction of the opals, with the tiny sphere forming even sheets. It is these even sheets that produce the opalescence effect that opals are known for.

Ethiopian opal formation. Image courtesy of Opal Galaxy.  

In contrast to the sedimentary, low temperature, method of formation, Ethiopian opal formed from the hydrothermal waters associated with volcanic activity. The hydrothermal waters reacted with the volcanic ash and rhyolites, dissolving the silica, then reprecipitating it within the voids of the surrounding volcanic rocks. They are also hydrophane, meaning they actively absorb water. This means that they are far more unstable than the Australian opals, and much more chemically reactive. They are also much, much younger, having formed likely in the last few thousand years. 

Coming back to Taylor Swift

Let's look at some of the lyrics for "Opalite", specifically the refrain:
And that's when I told you
It's alright
You were dancing through the lightning strikes
Sleepless in the onyx night
But now the sky is opalite
Oh oh oh oh, oh my Lord
Never met no one like you before
You had to make your own sunshine
But now the sky is opalite
Oh oh oh oh oh

She really does only have the two geological terms in the song and they are "opalite" and "onyx". We will start with the big one, opalite.

What is does the word "Opalite" even mean?

The term "opalite" is a very uncommon word. It does not appear in either my geological dictionary, or my Webster dictionary, nor Merriam-Webster's website, nor the Cambridge Dictionary. 

I was able to find some dictionaries, which did have a result including, Dictionary.com which defines "opalite" as: "an artificial gem resembling an opal." This is akin to Taylor Swift's usage of the word. 

However, there is also a second definition for "opalite", which predates the "artificial" usage of the word. Per 1945's Dictionary of Gems and Gemology:

Opalite - "Term used for impure, colored varieties of common opal." 

Geology.com expands upon this and clarifies, stating that the term opalite is used "as a synonym for common opal (natural opal that does not exhibit play-of-color)."


So we have two usages for "opalite".

What does the geological definition of "opalite" mean?

When we look at the formation of an opal, the orderly arrangement of the micro-spheres is essential to the play of color known as opalescence. If that orderly arrangement is not met, then there is just chaos, and the light effects will be absent. Here you will get what is known as "common opal", or "potch", or ... "opalite". 

Common opal, or "opalite". Image courtesy of geology.com. 

In this instance, opalite refers to the non-opalescent varieties of opal. Or in terms of money, the non-gemstone varieties of opal.

What is the synthetic opal definition of "opalite" mean?

Synthetic, or man-made, is exactly as it sounds. These are opals manufactured by man. Unfortunately, these man made opals are more akin to the geological definitions of opalites than they are to opals because, while they may have some opalescence, they lack the opalescence of natural opals. 

Synthetic opals, AKA opalites. Image coutesy of Synthetic Opals.

Because man-made opalites have such a rigid structure, much more so than even highly ordered natural opals, the opalescence that is achieved has a "lizard skin appearance" and lacks the natural variety and irregular patterns. Per Opal Minded: "Most fake opals show fragments of coloured material trapped in a clear base, giving a “shattered” or artificial sparkle rather than the fluid, shifting flashes of a genuine opal."

SEM image of a man-made opal. Image courtesy of Synthetic Opals.  

However, as you can see in the SEM image above, the structure of the synthetic opalite is very much akin to the structure of the natural opals, but it does give a synthetic appearance, which the natural variety feels more variable.

How could "Sleepless in the onyx night" relate to opalite?

I find it funny that she picked onyx, because like opal, it is also composed of silica. Onyx, however, is a mineral, not a mineraloid like opals are. Onyx is a variety of the mineral chalcedony, which in of itself is a variety of quartz. Chalcedony, and therefore onyx, is comprised of microcrystalline quartz instead of one big crystal of quartz like amethyst. 

A black and white variety of onyx. Image courtesy of GeologyScience.

What makes onyx a distinctive variety of chalcedony, is that it has straight, parallel bands of alternating colors, typically black and white. This means that while onyx typically has a "black and white" banded structure, it is distinctly different from natural opalite, both in variety of color and the variety of shapes possible with the color patterns. 

In Summary

Taylor Swift builds Opalite as a means to make ones own happiness from the onyx night. And the fact that you can physically make the synthetic opalite from onyx, plays even more into her song by allowing people to make their own happiness from what they are give. When life hands you lemons and all that. And that's pretty cool.
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