Permian Formations

The Hermit Formation or Hermit Shale forms slopes above the Supai Group that are reddish brown in color and comprised of siltstone, mudstone, and sandstone. Dark red paleochannels (river remnants) intermingle with red and white sandstone and siltstone beds. It also contains some poorly preserved plant fossils.

The Coconino Sandstone, found all along the Colorado Plateau, is a cliff forming white colored layer. Made of mostly quartz and potassium feldspar, this layer was formed through eolian (wind-deposited) processes and contain incredibly well preserved environmental records. At this time, quartz sand was being deposited in desert area of growing sand dunes. There are fossilized tracks of lizards, scorpions, and millipedes.

The Toroweap Formation is a slope-forming collection of gypsum, shale, and sandstone. These deposits were from the receding shores of a shallow sea in the area. There are three section to the formation. The Seligman section is a slope-forming warm-colored sandstone and siltstone mix. The Brady canyon section is a slope-forming grey limestone interspersed with chert. The Wood Ranch section is a slope-forming red and grey siltstone and dolomitic sandstone. There is an unconformity at the top of this formation.

The Kaibab Limestone is the youngest formation in the canyon. It is a cream to grayish white rock and it is what visitors stand on when visiting both of the rims. It was formed by the advancements of a shallow sea. Sediments were deposited and today contain many marine fossils like that from sharks, mollusks, worms, corals, etc.

In some areas, there is an even newer formation called the Moenkopi Formation. It is a red sandstone formed from tidal deposits. Though mostly found in Utah and Colorado, it does appear in the Grand Canyon.