Rocks You Need To See – The Amazing Geology In Cataract Canyon
By Kim Cassels • July 2, 2019
Rocks You Need To See – The Amazing Geology In Cataract Canyon
The geology in Cataract Canyon is an intricate carving made by the Colorado River. This canyon encapsulates an assortment of strange and stunning formations moseying through Canyonlands National Park. It’s a gallery made from an archaic ocean, freshwater marshes, sand dunes, and thick jungles near the equator. What remains is a lively desert that has evolved through eons of deposition and erosion.
Southwestern Utah was once a series of islands, similar in arrangement to the Mediterranean. Off and on, it was either connected or isolated from the ocean creating the Paradox Sea. The ocean was cut off 29 times for 15 million years. During these periods, the water evaporated and left its salt behind. Each time the sea flooded, the salt was covered again and again by layers of sediment. While this salt foundation is two kilometers thick, it isn’t particularly solid. Salt continuously moves back and forth (or east and west in this case) like toothpaste in its tube. This creates the diagonal landscape around Moab, which continues to slowly slide.
Utah’s sculptures are a cocktail of sedimentary rocks stirred and shaken by waves and sea breeze. Tectonic plates nudged each other and molten climbed to the surface, creating the uprising of the Colorado Plateau that left the sea behind. Today, the ancient seabed is riddled with amphitheaters, statues, and multi-layered plateaus in a constant chisel. If you make your way to this vivid terrain, rafting through Cataract Canyon displays an incredible view from below. Here are some of the phenomenal sights that appear along the drift.
Tex’s Grotto
Shortly after the launch, you’ll come to a concert venue only accessible from the Colorado River.
This natural amphitheater is made of sandstone and limestone. Sandstone is more porous and sits on top of a stronger limestone layer. Water collects in these pores and runs on top of the limestone, dissolving the sandstone back into grain and leaving the limestone layer behind. Gravity and exfoliating wind slough off the outer layer to create the dramatic curvature in this cliff.
Once a year, a full orchestra hikes into this stone amplifier for a remote performance. While a helicopter drops in a grand piano, musicians lug their basses and cellos through the thicket. The audience dines across the river while the symphony fills the canyon. Witnessed by few, it is most likely one of the most unique musical evenings someone could experience.
Dead Horse Point
Going deeper into Cataract Canyon, you’ll arrive beneath Dead Horse Point State Park.
If the sediment of Utah’s rock formations is like a stirred cocktail, think of Dead Horse Point as a Neapolitan cake. This park is cliffs on top of cliffs, on top of cliffs. Because the area is high and dry, brittle shale breaks off the heartier limestone layers in massive chunks. In this case, shale is ganache poured over a chocolate (sandstone/limestone) cake. Yum. This creates the vertical walls of this 2,000-foot descent down to the Colorado River.
The gigantic formation was named from the days of cowboys catching wild horses in the 1800s. They would corral the herd at the gooseneck behind a fence, pick the Mustangs they wanted, and free the rest to their feral lifestyles. There was an incident of leaving the unpicked horses behind the fence, leading them to die of thirst.
Granaries and Pictographs
Thousand year-old artifacts can be found amongst Cataract’s spectacular geology. Granaries and pictographs are dotted along the meander. They show us how the Colorado River has long been a source for resilient life.
Granaries are old and sturdy storage bins. They were made by the Puebloans who lived in Canyonlands between 10,000 and 2,000 years ago. Many are small and inconspicuous holes high in the cliffs. Others are larger and sculpted in clay beneath shallow alcoves. They imply a nomadic lifestyle, where grain and crops were stored to use for another time.
Ancient artwork rests on the walls often near these granaries. Pictographs of handprints, animals, and abstract human figures can be easily spotted or missed while hiking. Pictographs are painted, while petroglyphs are carved or pecked. The paint was a mixture of available sediment, like sandstone and limestone mixed with charcoal and animal fat or blood. These handprints were made just like our elementary school masterpieces, dipping our fingers in the paint, or placing our hand on the surface and brushing around the outside.
Dollhouse
Towards the end of Cataract Canyon is an array of looming spires and crooked hoodoos.
The Doll House is apart of the Maze in Canyonlands. It’s a remote area and requires thoughtful preparation to access it from the park. Luckily, floating along the Colorado River gives a spectacular view of the Doll House without the difficult hike.
This type of erosion begins with ice. Plateaus develop cracks, which fill with water and freeze. Ice expands the crevices leading the rock to crumble and separate from itself, making gaps in the once uniform structure. Now air and water can flow between these gaps, gradually shaving them down over time. What makes hoodoos so interesting in shape is their protective layer of stronger rock over the weaker layers, making the erosion disproportionate in areas. Spires are more uniform in shape because they are composed of stronger rock layers throughout.
Paradox Formation
Through Cataract Canyon is the rare and ornate exposure of the underlying layers of the Earth’s crust.
Due to the cyclical pattern of an isolated and flooding sea, the bottom layers of Utah’s foundation are incredibly different from the rock sequence above. In Cataract Canyon, the river allows us to see the Paradox Formation, which lies many layers beneath Moab. This is where the salt layer resides, always pushing and adjusting the rock layers above.
In Canyonlands, this layer is visible along the Colorado River. Volcanic and ashy in appearance, the salt is squished together with limestone, gypsum, and other minerals. Salt flows through the channels of least resistance. So as the rock layers above create pressure, the salt liquifies and rummages through the easiest pockets of available space- like toothpaste, remember? This process results in the creation of needles and arches, the bizarre designs we love so much.
Cataract Canyon is truly an expedition through time. From the labor of wind and water, to the hiding places of ancient peoples, the canyon offers sights only to be experienced from the Colorado River. Floating between these walls beckons the seldom seen beauty of this twisted and towering terrain.
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Moab, UT Rafting: Cataract Canyon in Canyonlands National Park
