Dunn Butte, is a 5,714 foot-elevation-summit, a minor butte, along a line of three summits along the west drainage of Ninetyone Mile Canyon and Creek. From higher elevation-to-lower, they are Angels Gate, Dunn Butte, and Hawkins Butte. The bases of all three landforms are connected, and Dunn Butte is a south-southwest ridgeline, with the high point prominence at the northeast terminus. The massif of Wotans Throne is adjacent 1.0 mi northeast. The

Cape Royal Cape Royal is a 7,880+-cliff-elevation summit located in the eastern Grand Canyon, Coconino County, Arizona, Coconino County of northern Arizona, Southwestern United States, United States. It is the southernmost viewpoint of the North Rim, viewi ...

viewpoint is ~2.0 mi northeast; Dunn Butte is 2.0 north of the Colorado River, its drainage point.

Geology

The prominence geology of Dunn Butte is based on the massifs of

Supai Group The Supai Group is a slope-forming section of red bed deposits found in the Colorado Plateau. The group was laid down during the Pennsylvanian to Lower Permian. Cliff-forming interbeds of sandstone are noticeable throughout the group. The Su ...

upon the

cliff-former A cliff-former is a geological unit of bedrock that is more resistant to erosion than overlying or underlying strata and consequently produces outcrops with high slope angles. It is more or less equivalent to ''ridge-former'', and may be contrast ...

, (and therefore platform-former), of Redwall Limestone. The Supai Group (and Redwall), massifs are also found on the parent (and connected landform), of Angels Gate, and neighboring butte northwest,

Thor Temple Thor Temple is a -elevation summit located in the Grand Canyon, in Coconino County of northern Arizona, United States. It is situated west-northwest of Cape Royal on the canyon's North Rim, east of Brahma Temple, and north-northwest of Wotans ...

Geology – Dunn Butte, Angels Gate, & Thor Temple

The three prominence-bases of neighboring Angels Gate and Dunn Butte, and close by

(northwest), are composed of

. Unit 4, Supai, is the

, (and therefor platform-former),

Esplanade Sandstone The Lower Permian Esplanade Sandstone is a cliff-forming, resistant sandstone, dark red, geologic unit found in the Grand Canyon. The rock unit forms a resistant shelf in the west Grand Canyon, south side of the Colorado River, at the east of t ...

, that has a common, and sometimes thick presence, in nearly all regions of the Grand Canyon. For Thor Temple, the prominence platform is rectangular, on a rectangular pyramid of Supai Group. The tabletop platform contains the debris of upper eroded members,

Hermit Shale 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 H ...

, (and maybe remainder rocks of Coconino Sandstone). For Angels Gate, two Coconino Sandstone prominences (upon slope-former Hermit Shale), lies upon a northwest-by-southeast platform of Esplanade Sandstone. Angel Gate's 6,761 ft height is identical to Thor Temple's 6,741 ft elevation. Dunn Butte, at 5,714 ft is ~1000 ft lower, and its platform ridgeline is Supai Group, unit 2, (the cliff and platform unit),

Manakacha Formation The (Upper) Late Pennsylvanian Manakacha Formation is a cliff-forming, sandstone, red-orange geologic unit, formed from an addition of eolian sand, added to marine transgression deposits, (siltstones, etc.), and found throughout sections of th ...

, upon slopes of slope-forming

Watahomigi Formation The Watahomigi Formation is a geologic formation in the Grand Canyon region of Arizona. It preserves fossils dating back to the Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years ...

. Again, the Supai Group lies upon the platform of the Redwall Limestone massif.

References

External links

{{commons category, Dunn Butte
Aerial view, Dunn Butte, Mountainzone
Grand Canyon Landforms of Coconino County, Arizona

Geology

Geology – Dunn Butte, Angels Gate, & Thor Temple

See also

References

External links