Disneyland's Big Thunder Mountain
My next entry in the Geology of the Disney parks is Disneyland's Big Thunder Mountain. I am specifying that this is "Disneyland's" version of the ride because even though the ride has been replicated three other times in parks around the world (two of which also have the a centerpiece dinosaur skeleton), this one is unique to Disneyland.
Here is the setup for the ride from Disneyland:
Legend has it that after gold was discovered in the 1850s, eerie incidents took place in the mine. Trains would take off and race through tunnels… by themselves.
As you enter the cursed cavern, your train speeds up along the rickety track. Shoot under a booming waterfall and dodge a falling boulder from an unexpected landslide as you swoop around sharp turns and drop into desolate canyons.
On this rip-roaring adventure, you may learn that some legends turn out to be true...
For Disneyland's version of Big Thunder Mountain, the theme of the ride is based on Bryce Canyon National Park in Utah. Per The Imagineering Field Guide to the Magic Kingdom, this is distinctly different than the Magic Kingdom's version of the ride, which is modelled after Monument Valley. The reason for this is the aesthetics of the rocks. Monument Valley Tribal Park in Utah and Arizona is comprised mainly of sandstones and shales, making the color palette of Monument Valley to be very red and orange.
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| Monument Valley Tribal Park in southern Utah |
While the rocks found in Bryce Canyon are a much more pinkish "magenta" color, matching the aesthetics of the nearby Fantasy Land. And since Big Thunder Mountain butts up against Fantasy Land, the mountains were used as a visual backdrop to the land and the color palette was chosen to blend in.
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| Bryce Canyon National Park in Utah |
The upright spires within Bryce Canyon, called hoodoos, were also mimicked in the upper portions of the ride. You can see them below clearly above the primary dinosaur skeleton. The reason for the color palette of Bryce Canyon is because of the type of rock that it is. Bryce Canyon is predominantly made up of limestone, with sandstone and shale interbedded with it. The rocks were deposited during the Eocene in a large lake bed, forming what is known as the Claron Formation.
The Claron Formation forms the Pink Cliffs part of Bryce Canyon and is broken up into two individual members: the Pink Limestone Member, which forms the reddish hoodoo rocks of the Pink Cliffs, and the slightly younger White Limestone Member. The White and Pink Limestone Members of the Claron Formation were deposited during the Eocene Period, approximately 60 to 50 million years ago. During that time, this part of Utah was covered by a vast lake, depositing thick layers of calcite that eventually consolidated into limestone. The Claron Formation also includes beds of siltstone and dolostone (like limestone but with dolomite instead of calcite). Limestone is also the same rock that caves form in because they dissolve in slightly acidic water
An interesting addition to the ride is the very notable dinosaur skeleton, which is easily visible from the queue. While you are riding the ride you arrive here towards the end, where as you whip around the track, you eventually end up face-to-face with a dinosaur skeleton. At first glance, you would think this is a T. rex skeleton. At least, I believe that is what it is meant to be.
While the ride itself was meant to mimic the bedded limestones of Bryce Canyon, it is notable that along the path around the corner to the main entrance to the ride, the rocks there look distinctly sandstone. So much so that the Imagineers carved in cross-beds into the rocks themselves. Cross beds are geological features when dunes are essentially frozen in time and turned into rocks. When sand moves across the desert in a dune they climb up one side of the dune then fall down the steep edge, known as the slipface. This pattern of movement is then preserved in the dune as a cross bed. And depending on how the cross beds are eroded, they can form really cool patterns, such as is imitated in the ride.
These cross bedded sandstones look amazingly like the sandstone beds of another national park located really close to Bryce Canyon NP, Zion National Park. Specifically the sandstones of the Navajo Formation, which is significantly older than that of Bryce Canyon's Claron Formation.
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| Navajo Sandstone crossbeds from Zion National Park |
The Navajo Sandstone is Early Jurassic in age, ~180 million years old. It is a very thick, ~1000 feet, eolian (desert) sandstone from an ancient sand sea known as an erg. This part of the ride likely stems from when this entire ride was built for Magic Kingdom, before parts of it were altered to fit in with Disneyland.
An interesting addition to the ride is the very notable dinosaur skeleton, which is easily visible from the queue. While you are riding the ride you arrive here towards the end, where as you whip around the track, you eventually end up face-to-face with a dinosaur skeleton. At first glance, you would think this is a T. rex skeleton. At least, I believe that is what it is meant to be.
However, looking closely at the skull, it appears ... off from an actual T. rex. Let's compare it to arguable the most famous T. rex, the Field Museum's SUE. Comparing the Big Thunder Mountain T. rex to SUE (pictured below), the biggest problem with the skull is the teeth. It's as if the designers tried to cram as many teeth as they could into the mouth, and all of the teeth are the same size and more rounded than real -life. Whereas, in the real skull the teeth are constantly coming to replace lost or worn teeth, so the size and spacing of the teeth differ widely within the actual T. rex's mouth. The overall dimensions of the fenestra (skull holes) are also smaller in the Disney skull than in the real animal. The nostril hole (the naris) is noticeably smaller, compared to the real skull, with everything getting a more boxy appearance, however I could attribute that to making the skull more durable with more surface area.
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| SUE the T. rex from the Field Museum in Chicago |
What I really wondered was where did the idea of this dinosaur come from. Was it meant to be a T. rex or something else. I find it really telling that the D23 post called "The Ultimate Dino-Tour of Disney Parks all Over the World" that goes over many of the dinosaurs in the Disney Parks just calls this "the bones of a dinosaur". No attempt was made at even naming the species, whereas they name the species of many of the other dinosaurs in the post.
Tony Baxter himself, designer of Big Thunder Mountain, stated that the dinosaur bones were meant as a tribute to the previous incarnation of the ride. Parts of the ride and theme were actually taken from the previous renditions of the ride called Rainbow Caverns Mine Train, which was then converted into the Mine Train through Nature's Wonderland. However, I haven't been able to find any pictures of any dinosaurs from those versions. The closest thing I could find, was that the second version mentioned dinosaurs during the ride, but that was about it.
So although many Disney fans seem to have unanimously determined that this is a T. rex skeleton, Disney itself has shied away from denoting it as anything other than a "dinosaur".
The location of these dinosaur bones is also suspect. If these bones are located in the "Bryce Canyon" portion of the the design, then they are clearly too old to be there. T. rex lived right up to the end of the Mesozoic, ~66 million years ago. The Claron formation is 60 to 50 million years old, which is too young. However the sandstone related formation on the outskirts of the ride is not the same as seen here with the bones in it. So perhaps this is meant to be a different limestone type deposit that underlies the Claron Formation and is therefore old enough to contain a T. rex?
References
Wright, Alex. The Imagineering Field Guide to the Magic Kingdom at Walt Disney World: An Imagineer's-eye Tour. Disney Editions, 2005.
