|
a beautiful hanging valley!
The Navajo is a thick, cross-bedded, eolian quartzose sandstone deposit representing migrating sand dunes in an ancient sand sea (erg facies). The reddish coloration is due to hematite cement and hematite staining (hematite = Fe2O3). In places, the Navajo Sandstone lacks hematite staining and is whitish-colored.
Bottom-up weathering and erosion of Navajo Sandstone cliffs has produced blind arches in places, which are large, arch-shaped structures.
Differential weathering and erosion has produced a pitted surface on some Navajo Sandstone cliff faces - this is honeycomb weathering. Honeycomb weathering is common in just about any cliff-forming sandstone unit.
Underlying the Navajo Sandstone is the Kayenta Formation (?Upper Triassic to Lower Jurassic). The Kayenta consists of fluvial redbeds (reddish-colored, hematite-rich siliciclastic sedimentary rocks such as shale, siltstone, and sandstone deposited in river and floodplain environments). The next unit down is the Moenave Formation (Upper Triassic), also consisting of nonmarine redbeds. representing stream, floodplain, and lake deposits.
The Navajo is a thick, cross-bedded, eolian quartzose sandstone deposit representing migrating sand dunes in an ancient sand sea (erg facies). The reddish coloration is due to hematite cement and hematite staining (hematite = Fe2O3). In places, the Navajo Sandstone lacks hematite staining and is whitish-colored.
Bottom-up weathering and erosion of Navajo Sandstone cliffs has produced blind arches in places, which are large, arch-shaped structures.
Differential weathering and erosion has produced a pitted surface on some Navajo Sandstone cliff faces - this is honeycomb weathering. Honeycomb weathering is common in just about any cliff-forming sandstone unit.
Underlying the Navajo Sandstone is the Kayenta Formation (?Upper Triassic to Lower Jurassic). The Kayenta consists of fluvial redbeds (reddish-colored, hematite-rich siliciclastic sedimentary rocks such as shale, siltstone, and sandstone deposited in river and floodplain environments). The next unit down is the Moenave Formation (Upper Triassic), also consisting of nonmarine redbeds. representing stream, floodplain, and lake deposits.