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 Wotans Throne is a summit located in the Grand Canyon, in Coconino County, Arizona, US. It is situated one mile immediately southwest of the Cape Royal overlook on the canyon's North Rim, 1.7 miles west-southwest of Freya Castle, two mil ...

is adjacent 1.0 mi northeast. The Cape Royal viewpoint is ~2.0 mi northeast; Dunn Butte is 2.0 north of the

Colorado River The Colorado River () is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and in northern Mexico. The river, the List of longest rivers of the United States (by main stem), 5th longest in the United St ...

, 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 sequence of mixed red beds and limestones that outcrop in the Colorado Plateau. The group was laid down during the Pennsylvanian to Lower Permian. Cliff-forming interbeds of sandstone are noticeable througho ...

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 Redwall Limestone is an erosion-resistant, Mississippian age, cliff-former, cliff-forming geological formation that forms prominent, red-stained cliffs in the Grand Canyon. these cliffs range in height from to . It is one of the most fossili ...

. 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 GC

Geology – Dunn Butte, Angels Gate, & Thor Temple

The three prominence-bases of neighboring Angels Gate and Dunn Butte, and close by Thor Temple (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 th ...

, 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, (and maybe remainder rocks of

Coconino Sandstone The Coconino Sandstone is a geologic formation (geology), formation composed of light-colored quartz arenite of Aeolian processes, eolian origin. It erodes to form conspicuous, sheer cliffs in the upper walls of Grand Canyon, as part of the Mog ...

). 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 (geology), Pennsylvanian Manakacha Formation is a cliff-former, cliff-forming, sandstone, red-orange geologic unit, formed from an addition of aeolian processes, eolian sand, added to marine transgression deposits, ...

, 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 period. See also * List of fossiliferous stratigraphic units in Arizona * Paleontology in Ariz ...

. Again, the Supai Group lies upon the platform of the

massif.

References

External links

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