Delicate Arch in Utah is photographed during sunset through the window of another arch. Only the Entrada sandstone has the nature of generating arches. This explains the high frequency occurrence of arches at only few sites in this region. The Entrada was sedimented in a flat marginal sea during the Jurassic age. Only few million years later this ocean regressed again leaving a desert with dunes. These dunes are represented by a white stratum of sandstone that is free of arches.
Canon 20D, EF-S 10-22mm, f/22, 1sec, ISO 100, polarization filter, tripod