(DAILY MAIL) — Approximately 88 human ‘ghost tracks’ have been discovered in salt flats of Utah’s Great Salt Lake desert that are believed to be more than 12,000 years ago and only appear when there is just the right amount of moisture – and then disappear when there it is not.
A team of researchers led by Cornell University determined the prints belonged to adults and children who were walking through shallow water during the Ice Age, when the now dry landscape was cloaked in wetlands. The sand in the water quickly filled in their footprints, but mud underneath kept the prints intact.
Because the sand holds more moisture than the surrounding sediment, the right amount of water will make the footprints stand out among the tan colored ground – but then disappear again when the ground dries up.
