Hermit Formation
The soft red Permian slope beneath the Coconino cliff — a coastal red bed of ferns, conifers, and animal tracks, its top mudcracked beneath the dunes.
Also known as: Hermit, Hermit Shale
Permian — vast deserts, ending in the worst extinction ever
The world back then
Early Permian, about 287 million years ago. A broad, muddy coastal plain stretches out under a semi-arid sky — sluggish rivers, red silt, ferns and conifers, the ground cracking in the dry spells. Not dramatic; just a low, hot, dusty floodplain waiting for the desert to arrive. The mudcracks at the top are the last thing here before the dunes bury it.
That hot, dusty plain is the soft red slope under the white cliff, and you cross the whole thing between lunch and camp. It spent its entire existence waiting for the desert to bury it; you spend an afternoon drifting over its grave. The human struggle is real enough — but this particular afternoon is pure gravy.
Recognize it in the field
- Typical color
- reddish-brown (iron oxide)
- Weathers as
- Slope-former — a soft reddish-brown recessive slope beneath the Coconino cliff.
- Grain
- very fine sandstone and siltstone
Look for
- iron-oxide red beds
- deep mudcracks at the top (filled by the Coconino)
- soft and poorly resistant
- thickens dramatically westward
How this rock was made
A broad, semi-arid coastal plain of sluggish rivers before the Coconino dune sea.
The setting: low-gradient coastal plain / river (fluvial), with wind-blown dust (loess) and scattered dunes
~160 ft (east) to ~800 ft (west).
In the rock record
↑ Younger — rests above
↓ Older — sits beneath
Where to see it
Regions: Grand Canyon / Colorado Plateau
- Hermit Basin / Hermit Trail (type locality)
- the red slope beneath the Coconino throughout the Grand Canyon
Float past it: Grand Canyon