While at the beginning of July, they went to an excavation site near the Hill Air Force Base, a US Air Force military base located in the Great Salt Lake Desert (Utah, USA), archaeologists accidentally came across mysterious “ghost footprints”. These appeared to be few in number, but a thorough scan of the surrounding area revealed no less than 88 individual barefoot tracks, dating back to at least 10,000 years ago. A “unique” discovery, described in a press release dated July 26, 2022 and spotted by LiveScience.
Ice Age Footprints
These “phantom footprints” get their strange name not from a possible paranormal phenomenon, but because they only become visible after rain. They fill with moisture and then become darker, before disappearing again after a sunny episode. This is how they revealed themselves to scientists, in the middle of the salt flats.
About 15,000 years ago, a huge saltwater lake covered two-thirds of Utah, much like the nearby Great Salt Lake (whose desert titles the name). All that remains is a vast carpet of hard and regular salt, the result of the slow evaporation of water after the end of the last glacial period (the Pleistocene, – 2.6 million years to – 11,700 years ago) . But during this transition, the area briefly became a large wetland, occupied by humans. The conditions there were then perfect for the creation of these “ghost footprints”, according to the researchers.
10,000 years ago — possibly 12,000, during the latter part of the Pleistocene, archaeologists estimate — people in the area appear to have walked barefoot in the shallow waters, sand filling in their tracks behind them. The footprints of adults and children of about 5 to 12 years of age finally remained intact thanks to the layer of mud hiding under the grains. As the water dried up, they filled with salt, making them invisible in the landscape. But when it rains, the drops normally absorbed by the sediment are trapped in the old tracks, creating dark spots and revealing them in broad daylight.
A more precise dating, carrying information
Just next door (1.7 kilometers), archaeologists had already found an ancient hunter-gatherer camp dating back to 12,000 years ago, which left behind a fireplace, stone tools, 2,000 burnt bird remains and charred tobacco seeds. Could it be the same group?
The area is known for discoveries of ancient human tracks. In 2021, 60 human footprints dated between 21,000 and 23,000 years old were found in White Sands National Park (New Mexico). They would constitute the oldest evidence of humans in the Americas.
Researchers are currently analyzing the newly discovered “ghost footprints” to try to date them precisely — which is why they haven’t yet been published in a scientific journal. Thanks to carbon-14 dating, they hope to be able to inspect potential small pieces of organic matter that could have remained trapped in the sediments.
There is an immediate human connection to seeing human footprints. Seeing them from the distant past, so different from what the world is today, is impactful — Daron Duke, principal investigator and archaeologist at the Far Western Anthropological Research Group.
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