Mirabilite deposits are often found beneath the waters of the Great Salt Lake in winter, but this is the first time the mineral has formed exposed mounds above the surface.
(Image: © Courtesy Utah Geological Survey)
Rare mounds of a crystalline mineral have emerged above the surface of Utah’s Great Salt Lake, where they’re expected to remain just a few months before disappearing again. Scientists think these mounds may be similar to mineral structures on Mars that could preserve traces of microbes that may have lived in the planet’s saltwater lakes billions of years ago.The four white mounds, which measure up to 3 feet (1 meter) high and dozens of feet across, were first seen near the southern shoreline of the Great Salt Lake in October by park ranger Allison Thompson, Utah State Parks representatives wrote in a blog post.Related: Photos: The World’s Weirdest Geological FormationsThompson noticed that the mounds grew as the winter deepened, and she called in members of the Utah Geological Survey to investigate.After taking samples for chemical tests, the state geologists determined that the mounds are layered formations of a mineral known as mirabilite, a crystalline sodium sulfate. The scientists think the mounds will remain only as long as the weather stays below freezing; in the spring, the mirabilite will dissolve in the warmer waters, and the mounds will disappear.Geologists think the mounds of mirabilite have precipitated from the salty lake water above sulfate-rich hot springs near the shore. (Image credit: Courtesy Utah Geological Survey)Mineral moundsThe mounds of mirabilite are up to 3 feet high and dozens of feet across; and scientists think similar mineral structures might preserve signs of ancient life on Mars. (Image credit: Courtesy Utah Geological Survey)Mirabilite often forms beneath the salt-rich waters of the Great Salt Lake, but this is the first time the mineral has emerged as mounds above the surface, said Mark Milligan, a geologist with the Utah Geological Survey.”There are mirabilite deposits