The Great Salt Lake has something in common with the planet Mars and the Arctic.
Four unusual mineral formations made up of mirabilite, also known as Glauber’s salt, have sprung up along the Great Salt Lake shoreline, just north of the Great Salt Lake marina, according to a press release from Utah State Parks.
The mounds have grown up to 3 feet tall, the release says, and several yards wide. They’re in close proximity to each other, forming a curving line along the shoreline, a few dozen yards apart.
From a distance, the formations look somewhat like a pile of snow. Close up, the crystal-like structure of the salt is more apparent.
“A closer inspection of the mounds revealed that they are a built-up collection of crystallized terraces,” the release says, “similar in appearance to the travertine rimstone and dam terraces that form at Mammoth Hot Springs in Yellowstone National Park.”
This is the first time mirabilite formations have been documented at the lake, the release says.
These formations are rare, having only been found at a few locations around the world, the release says, mainly in the Arctic.
In addition to their rarity, they are valuable to researchers for another reason.
“Researchers are particularly interested in the precipitation of mirabilite mounds because they may serve as analogues to similar features and conditions on Mars,” the release says.
Park Ranger Allison Thompson noticed the unusual mounds along the Great Salt Lake shoreline in October. After seeing that they were continuing to grow, she reached out to the Utah Geological Survey for help investigating the formations.
“Geologists have determined that the mirabilite is precipitating from warm, high salinity sulfate-rich springs, visible only when the lake level falls below an elevation of 4,194 feet,” the releases says.
They are near each other because the formations block their source, the springs, as they accumulate, leading to another formation popping up nearby.
The formations may not be there for long, though, because they can only exist at temperatures below freezing. As the weather warms, the crystals dehydrate, the release says, leaving a white powder mineral called thenardite.
Because the formations are so valuable for research, and so short lived, the Utah State Parks requests that visitors refrain from damaging them or removing portions of the material.