On Racetrack Playa, in Death Valley, California, rocks from a few centimetres in diameter to half a metre have trails hundreds of metres long showing that they have moved across the ground.
The most likely explanation involves the rain and melting snow from the surrounding hills in Spring, leaving many of the rocks partly-submerged in enormous, shallow pools. As temperatures fall at night, ice can form a collar around the base of a rock. This creates enough buoyancy for strong winds to overcome friction with the lake bed. This is only possible because of the flatness of the Playa, which allows wind to gust at 90 mph close to the ground.
A variation of this theory suggests that rather than just a collar, the stones are actually floated by ice rafts and moved by lighter winds.
In any case, the movement probably on lasts less than a minute and may only occur every several years.
From The Guardian