ArchThe photo above showing a facade of sandstone adorned with naturally carved gargoyle-like figures was taken in Arches National Park, Utah.  Photographer: Nel Graham

Delicate Arch (at left center) is the centerpiece of the park and composed of Entrada Sandstone. This area of Utah is part of the Colorado Plateau — much of the rock here is Jurassic-age Navajo Sandstone. During the Mesozoic Era, what is now southern Utah was part of a giant “sand sea,” which in terms of extent rivaled the current day Sahara Desert. Rocks are tinted shades of red/orange due to the presence of iron oxide in the form of hematite — common rust.

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