Coconino Sandstone

Either the Kaibab Limestone or Toroweap Formation overlies the Coconino Sandstone.

It consists primarily of fine well-sorted quartz grains, with minor amounts of potassium feldspar grains deposited by eolian processes (wind-deposited) approximately 275 million years ago.

Several structural features such as ripple marks, sand dune deposits, rain patches, slump marks, and fossil tracks are not only well preserved within the formation, but also contribute evidence of its eolian origin.

[3][4][5] Lechatelierite (silica glass), as well as coesite and stishovite (high pressure forms of SiO2) were formed during the impact of a meteorite into the Coconino Sandstone at Barringer Crater in Arizona.

[6][7] Sequence of layers: Coconino Sandstone on Hermit Shale on sloping redbeds of Supai Group.

The Coconino Sandstone forms the two prominent white cliffs in the middle distance in this view from the South Rim of the Grand Canyon.
Vertebrate tracks known as Chelichnus gigas from the Coconino Sandstone in Grand Canyon.
Sequence in section of North Rim showing rockfall :
White Coconino on eroded slope of Hermit Shale upon resistant & sloping Supai Group – ”redbeds” .