English: Sandstones in the Permian of Arizona, USA.

The walls of this Arizona canyon are composed of the Lower Permian De Chelly Sandstone (pronounced "De Shay"). Most of the unit is horizontally-bedded and cross-bedded quartzose sandstones representing ancient sand sheets and desert sand dunes. A vast sand dune "sea" was present at the time - such an environment is called an "erg" (a modern example is northern Africa's Sahara Desert). The reddish-brown coloration is from hematite (iron oxide, Fe2O3).

Stratigraphy: De Chelly Sandstone, Leonardian Stage, Lower Permian

Locality: view from Junction overlook, southern rim of Canyon de Chelly, Canyon de Chelly National Monument, northeastern Arizona, USA