Sailing stones

Sailing stones (also called sliding rocks, walking rocks, rolling stones, and moving rocks) are part of the geological phenomenon in which rocks move and inscribe long tracks along a smooth valley floor without animal intervention. The movement of the rocks occurs when large, thin sheets of ice floating on an ephemeral winter pond break up in the sun. Trails of sliding rocks have been observed and studied in various locations, including Little Bonnie Claire Playa, in Nevada,^[1] and most famously at Racetrack Playa, Death Valley National Park, California, where the number and length of tracks are notable.