Archaeological finds at the site included an ancient fireplace, stone tools used for cooking, a pile of more than 2,000 animal bones and charred tobacco seeds, which are the earliest evidence of tobacco use in humans. Less than a mile (1.6 kilometers) away from where the tracks were uncovered, a previous research group uncovered a hunter-gatherer camp dating to 12,000 years ago, where the humans who left the prints might have lived. But when the rain falls on top of the hidden muddy footprints, the water gets trapped, creating patches of dark and wet sediment that stand out from their surroundings. Normally, when it rains, the water is quickly absorbed deep into the surrounding sediment, which means the ground quickly returns to its normal color. "But under the sand was a layer of mud that kept the print intact after infilling." The footprints have since been filled in with salt as the wetlands dried out, making them indistinguishable from the surrounding landscape when they're dry, Duke added. People appear to have been walking in shallow water, with the sand rapidly infilling their print behind them, much as you might experience on a beach," lead researcher Daron Duke, an archaeologist with Far Western Anthropological Research Group, a private firm that specializes in cultural resources management, said in the statement. Researchers stand next to one of the ghost footprints uncovered at Hill Air Force Base.
0 kommentar(er)
