Time warp. Mighty salt layers beneath the bedrock of the Entrada sandstone cause a density and hence buoyancy driven vertical displacement, called diapir. The Entrada formation disrupts into vertical fins during this still ongoing uplift process. Parts of these thin fins gravitationally collapse. These forms get rounded by wind and water. In the end fragile arches develop before they finally collapse.
Pentax K2, Pentax 28mm, f/22, 1/4sec, Kodak Ektachrome E6, ISO 100, polarization filter, tripod