The geology of the Grand Canyon area includes one of the most complete and studied sequences of rock on Earth. The nearly 40 major sedimentary rock layers exposed in the Grand Canyon and in the Grand Canyon National Park area range in age from about 200 million to nearly 2 billion years old. Most were deposited in warm, shallow seas and near ancient, long-gone sea shores in western North America. Both marine and terrestrial sediments are represented, including lithified sand dunes from an extinct desert. There are at least 14 known unconformities in the geologic record found in the Grand Canyon.
The Cutler Formation or Cutler Group is a rock unit that is exposed across the U.S. states of Arizona, northwest New Mexico, southeast Utah and southwest Colorado. It was laid down in the Early Permian during the Wolfcampian epoch.
The Kaibab Limestone is a resistant cliff-forming, Permian geologic formation that crops out across the U.S. states of northern Arizona, southern Utah, east central Nevada and southeast California. It is also known as the Kaibab Formation in Arizona, Nevada, and Utah. The Kaibab Limestone forms the rim of the Grand Canyon. In the Big Maria Mountains, California, the Kaibab Limestone is highly metamorphosed and known as the Kaibab Marble.
The Tonto Group is a name for an assemblage of related sedimentary strata, collectively known by geologists as a Group, that comprises the basal sequence Paleozoic strata exposed in the sides of the Grand Canyon. As currently defined, the Tonto groups consists of the Sixtymile Formation, Tapeats Sandstone, Bright Angel Shale, Muav Limestone, and Frenchman Mountain Dolostone. Historically, it included only the Tapeats Sandstone, Bright Angel Shale, and Muav Limestone. Because these units are defined by lithology and three of them interfinger and intergrade laterally, they lack the simple layer cake geology as they are typically portrayed as having and geological mapping of them is complicated.
The Muav Limestone is a Cambrian geologic formation within the 5-member Tonto Group. It is a thin-bedded, gray, medium to fine-grained, mottled dolomite; coarse- to medium-grained, grayish-white, sandy dolomite and grayish-white, mottled, fine-grained limestone. It also contains beds of shale and intraformational conglomerate. The beds of the Muav Limestone are either structureless or exhibit horizontally laminations and cross-stratification. The Muav Limestone forms cliffs or small ledges that weather a dark gray or rusty-orange color. These cliffs or small ledges directly overlie the sloping surfaces of the Bright Angel Shale. The thickness of this formation decreases eastward from 250 feet (76 m) in the western Grand Canyon to 45 feet (14 m) in the eastern Grand Canyon. To the west in southern Nevada, its thickness increases to 830 feet (250 m) in the Frenchman Mountain region.
Except where underlain by the Sixtymile Formation, the Tapeats Sandstone is the Cambrian geologic formation that is the basal geologic unit of the Tonto Group. Typically, it is also the basal geologic formation of the Phanerozoic strata exposed in the Grand Canyon, Arizona, and parts of northern Arizona, central Arizona, southeast California, southern Nevada, and southeast Utah. The Tapeats Sandstone is about 230 feet (70 m) thick, at its maximum. The lower and middle sandstone beds of the Tapeats Sandstone are well-cemented, resistant to erosion, and form brownish, vertical cliffs that rise above the underlying Precambrian strata outcropping within Granite Gorge. They form the edge of the Tonto Platform. The upper beds of the Tapeats Sandstone form the surface of the Tonto Platform. The overlying soft shales and siltstones of the Bright Angel Shale underlie drab-greenish slopes that rise from the Tonto Platform to cliffs formed by limestones of the Muav Limestone and dolomites of the Frenchman Mountain Dolostone.
The Middle Permian Toroweap Formation is a thin, darker geologic unit, between the brighter colored units of the Kaibab Limestone above, and Coconino Sandstone below. It is a prominent unit in Grand Canyon, Arizona, USA, found through sections of the South Rim, Grand Canyon, and the North Rim, of the Kaibab Plateau; also the Kaibab's southeast extension to Cape Royal, the Walhalla Plateau. The Colorado River of the Grand Canyon makes its excursion from due-south to due-west around the Walhalla Plateau, as it enters the east end of the Grand Canyon's interior, Granite Gorge. The formation is also found in southeast Utah.
Isis Temple is a prominence in the Grand Canyon, Arizona, Southwestern United States. It is located below the North Rim and adjacent to the Granite Gorge along the Colorado River. The Trinity Creek and canyon flow due south at its west border; its north, and northeast border/flank is formed by Phantom Creek and canyon, a west tributary of Bright Angel Creek; the creeks intersect about 3 mi (4.8 km) southeast, and 1.0 mi (1.6 km) north of Granite Gorge. The Isis Temple prominence, is only about 202 ft (62 m) lower than Grand Canyon Village, the main public center on Grand Canyon’s South Rim.
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 the Toroweap Fault, down-dropped to west, southeast of Toroweap Overlook, and west of Havasupai. The red, sandstone shelf, The Esplanade is about 20-mi long. At Toroweap Overlook region, Toroweap Valley with Vulcan's Throne, Uinkaret volcanic field, the resistant Esplanade Sandstone is described in access routes exploring the Toroweap Lake area.
The (Upper) Late Pennsylvanian Wescogame Formation is a slope-forming, sandstone, red-orange geologic unit, formed from an addition of eolian sand, added to marine transgression deposits, and found throughout sections of the Grand Canyon, in Arizona, Southwest United States. It is one of the upper members of the Supai Group 'redbeds', with the Supai Group found in other sections of Arizona, especially in the Verde Valley region, or as a basement unit below the Mogollon Rim, just eastwards or part of the basement Supai Group of the southwest & south Colorado Plateau.
The Surprise Canyon Formation is a geologic formation that consists of clastic and calcareous sedimentary rocks that fill paleovalleys and paleokarst of Late Mississippian (Serpukhovian) age in Grand Canyon. These strata outcrop as isolated, lens-shaped exposures of rocks that fill erosional valleys and locally karsted topography and caves developed in the top of the Redwall Limestone. The Surprise Canyon Formation and associated unconformities represent a significant period of geologic time between the deposition of the Redwall Limestone and the overlying Supai Group.
The Bright Angel Shale is one of five geological formations that comprise the Cambrian Tonto Group. It and the other formations of the Tonto Group outcrop in the Grand Canyon, Arizona, and parts of northern Arizona, central Arizona, southeast California, southern Nevada, and southeast Utah. The Bright Angel Shale consists of locally fossiliferous, green and red-brown, micaceous, fissile shale (mudstone) and siltstone with local, thicker beds of brown to tan sandstone and limestone. It ranges in thickness from 57 to 450 feet. Typically, its thin-bedded shales and sandstones are interbedded in cm-scale cycles. They also exhibit abundant sedimentary structures that include current, oscillation, and interference ripples. The Bright Angel Shale also gradually grades downward into the underlying Tapeats Sandstone. It also complexly interfingers with the overlying Muav Limestone. These characters make the upper and lower contacts of the Bright Angel Shale often difficult to define. Typically, its thin-bedded shales and sandstones erode into green and red-brown slopes that rise from the Tonto Platform up to cliffs formed by limestones of the overlying Muav Limestone and dolomites of the Frenchman Mountain Dolostone.
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,, and found throughout sections of the Grand Canyon. It is one of the lower members of the Supai Group, with the Supai Group found in other sections of Arizona, especially in the Verde Valley region, or as a basement unit below the Mogollon Rim, just eastwards or part of the basement Supai Group of the southwest & south Colorado Plateau.
Horus Temple is a 6,150 ft elevation summit located in the Grand Canyon, in Coconino County of Arizona, Southwestern United States. This butte is situated as the central landform in a 3-series line of peaks southwest of the Shiva Temple (forested)-tableland prominence.
Whites Butte is a 4,860-foot (1,480 m) prominence adjacent the course of the Colorado River near the beginning of the Western Grand Canyon,. The butte lies at the terminus of Travertine Canyon, the adjacent canyon west of Hermit Canyon. The Boucher Trail which begins at Upper Hermit Canyon, courses the east base of Whites Butte to reach the Tonto Trail-(west), on the Tonto Platform, south side of the Colorado River.
Scorpion Ridge is a 5,832-foot (1,778 m) prominence, and a ridgeline-landform shaped like a scorpion, composed of the colorful red-orange Supai Group rocks, a linear ridge with two south-projecting arms of ridgeline that trend south to the Colorado River. Scorpion Ridge is approximately 11 miles (18 km) northwest of Grand Canyon Village near the beginning of West Grand Canyon. The Scorpion Ridge-Sagittarius Ridge north–south ridges are adjacent west to the North Rim ridgeline that extends south to Imperial Point, overlooking the beginning of West Grand Canyon. The position of Scorpion Ridge causes the Colorado River to flow west, then northwest, then north. Surrounding the two ridgelines to the Colorado, the river has the Serpentine Rapids west, the Sapphire Rapids, and the Willie Necktie Rapids, just downstream from Tuna Creek confluence, and Canyon, the major drainage at the east of the Imperial Point ridge.
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.
Castor is a 6,221-foot-elevation (1,896-meter) summit located in the Grand Canyon, in Coconino County of northern Arizona, United States. It is situated 11 miles west-northwest of Grand Canyon Village, and less than one mile north of Piute Point. Pollux Temple is one mile southeast, and Geikie Peak is three miles to the east. Topographic relief is significant as Castor Temple rises over 3,800 feet above the Colorado River in two miles.
Fishtail Mesa is a linear, narrow plateau, adjacent the west-flowing Colorado River in western Grand Canyon, in Coconino County, Northern Arizona, about 2.0 miles east of Kanab Point, and the outfall of south-flowing Kanab Creek, a major north tributary of the Colorado River, from southern Utah. Fishtail Mesa is part of the North Rim (west) and also lies 4.0 miles west of the outfall of Deer Creek, and Deer Creek Falls at the Colorado, a common stopover campsite for river rafters. The linear and southwest direction of Fishtail Mesa, lies adjacent as the southwest border of Fishtail Canyon ; at the Colorado, the Fishtail Rapids occur as minor rapids of the Colorado River. Some other nearby prominences to Fishtail Mesa, are Paguekwash Point, about 5.0 miles southwest, and Mount Sinyella, 8.0 miles south-southwest, and on the South Rim region of the Grand Canyon.
