Pictured above are gigantic sandstone boulders in a gravel pit near Rosie Arkansas. While these house-sized boulders are not unusual, their location is: there is no nearby source for them. Some geologists speculate that they were transported to this location by a great tsunami generated during a major meteorite impact. Perhaps the same meteorite that caused that tsunami created the 110 mile diameter Chicxulub crater on the Yucatan peninsula about 65 million years ago.
For more views of the Rosie boulders look here