Moqui marbles on a sandstone slope. (Marjorie Chan, University of Utah) Hikers rambling through Utah's candy-striped canyons sometimes come across a strange-looking sight. Where the Navajo Sandstone ...

The fantastical arch shapes of sandstone formations have long been thought to be sculpted by wind and rain. But a team of researchers has now found that the shapes are inherent to the rock itself.