Hermit Formation

Hermit Formation
Stratigraphic range: late Artinskian–early Kungurian
(Isis Temple, central Grand Canyon)
The 3 top geologic units visible:
3)-(white-cliffs-prominence)-Coconino Sandstone, 2)-(slope-forming-Deep brnsh-red)-Hermit Formation, 1)-(red-uppermost-vertical-cliff & resistant)-Esplanade Sandstone (top unit of 4–member Supai Group)
(Note: Distinctive Redwall Limestone upper horizontal-platform.)
TypeGeological formation
UnderliesCoconino Sandstone
OverliesSupai Group
Thickness900 feet (270 m), at maximum
Lithology
Primarysandstone and mudstone
Othersiltstone and intraformational conglomerate
Location
RegionArizona, California and Utah
CountryUnited States
Type section
Named forHermit basin, Coconino County, Arizona
Named byNoble (1922)

The Permian Hermit Formation, also known as the Hermit Shale, is a nonresistant unit that is composed of slope-forming reddish brown siltstone, mudstone, and very fine-grained sandstone. Within the Grand Canyon region, the upper part of the Hermit Formation contains red and white, massive, calcareous sandstone and siltstone beds that exhibit low-angle cross-bedding. Beds of dark red crumbly siltstone fill shallow paleochannels that are quite common in this formation. The siltstone beds often contain poorly preserved plant fossils. It outcrops across northwestern Arizona from the Sedona area, and it outcrops in the Grand Canyon and the western Mogollon Rim, into the Aubrey Cliffs. It forms steep slopes that are typically mostly covered by debris and colluvium derived from the overlying sedimentary strata.