Blue Mesa Member | |
---|---|
Stratigraphic range: Late Triassic, early Norian | |
Type | member |
Unit of | Chinle Formation |
Lithology | |
Primary | mudstone, sandstone |
Location | |
Region | Colorado Plateau |
Extent | Arizona Utah |
The Blue Mesa Member is a member of the Chinle Formation. It is located in the Petrified Forest National Park of northeast Arizona. [1]
The colorful bands of mudstone and sandstone were laid down during the Triassic, when the area was part of a huge tropical floodplain. [2]
The Painted Desert is a United States desert of badlands in the Four Corners area, running from near the east end of Grand Canyon National Park and southeast into Petrified Forest National Park. It is most easily accessed from the north portion of Petrified Forest National Park. The Painted Desert is known for its brilliant and varied colors: these include the more common red rock, but also shades of lavender.
Petrified Forest National Park is an American national park in Navajo and Apache counties in northeastern Arizona. Named for its large deposits of petrified wood, the park covers about 346 square miles, encompassing semi-desert shrub steppe as well as highly eroded and colorful badlands. The park's headquarters is about 26 miles (42 km) east of Holbrook along Interstate 40 (I-40), which parallels the BNSF Railway's Southern Transcon, the Puerco River, and historic U.S. Route 66, all crossing the park roughly east–west. The site, the northern part of which extends into the Painted Desert, was declared a national monument in 1906 and a national park in 1962. The park received 644,922 recreational visitors in 2018.
The Moenkopi Formation is a geological formation that is spread across the U.S. states of New Mexico, northern Arizona, Nevada, southeastern California, eastern Utah and western Colorado. This unit is considered to be a group in Arizona. Part of the Colorado Plateau and Basin and Range, this red sandstone was laid down in the Lower Triassic and possibly part of the Middle Triassic, around 240 million years ago.
The Chinle Formation is an Upper Triassic continental geological formation of fluvial, lacustrine, and palustrine to eolian deposits spread across the U.S. states of Nevada, Utah, northern Arizona, western New Mexico, and western Colorado. In New Mexico, it is often raised to the status of a geological group, the Chinle Group. Some authors have controversially considered the Chinle to be synonymous to the Dockum Group of eastern Colorado and New Mexico, western Texas, the Oklahoma panhandle, and southwestern Kansas. The Chinle Formation is part of the Colorado Plateau, Basin and Range, and the southern section of the Interior Plains. A probable separate depositional basin within the Chinle is found in northwestern Colorado and northeastern Utah. The southern portion of the Chinle reaches a maximum thickness of a little over 520 meters (1,710 ft). Typically, the Chinle rests unconformably on the Moenkopi Formation.
Smilosuchus is an extinct genus of leptosuchomorph parasuchid from the Late Triassic of North America.
Leptosuchus is an extinct genus of leptosuchomorph phytosaur with a complex taxonomical history. Fossils have been found from the Dockum Group and lower Chinle Formation outcropping in Texas, New Mexico, and Arizona, USA, and date back to the Carnian stage of the Late Triassic.
Machaeroprosopus is an extinct genus of mystriosuchin leptosuchomorph phytosaur from the Late Triassic of the southwestern United States. M. validus, once thought to be the type species of Machaeroprosopus, was named in 1916 on the basis of three complete skulls from Chinle Formation, Arizona. The skulls have been lost since the 1950s, and a line drawing in the original 1916 description is the only visual record of the specimen. Another species, M. andersoni, was named in 1922 from New Mexico, and the species M. adamanensis, M. gregorii, M. lithodendrorum, M. tenuis, and M. zunii were named in 1930. Most species have been reassigned to the genera Smilosuchus, Rutiodon, or Phytosaurus. Until recently, M. validus was considered to be the only species that has not been reassigned. Thus, Machaeroprosopus was considered to be a nomen dubium or "doubtful name" because of the lack of diagnostic specimens that can support its distinction from other phytosaur genera. However, a taxonomic revision of Machaeroprosopus, conducted by Parker et al. in 2013, revealed that UW 3807, the holotype of M. validus, is not the holotype of Machaeroprosopus, while the species Machaeroprosopus buceros, Machaeroprosopus being a replacement name, with a fixed type species, for Metarhinus, is the combinatio nova of the type species of the genu: Belodon buceros. Therefore, the name Pseudopalatus must be considered a junior synonym of Machaeroprosopus, and all species of the former must be reassigned to the latter. This revised taxonomy was already accepted in several studies, including Stocker and Butler (2013). Stocker and Butler (2013) also treated M. andersoni as a valid species, and not a junior synonym of Machaeroprosopus buceros as was previously suggested by Long and Murry (1995).
Parrishia is an extinct genus of sphenosuchian crocodylomorph known from the Late Triassic Chinle, Dockum, and Santa Rosa Formations in Arizona and New Mexico.
The Chinle Formation is an extensive geological unit in the southwestern United States, preserving a very diverse fauna of Late Triassic animals and plants. This is a list of fossilized organisms recoved from the formation.
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 Pliocene to Late Neogene Bidahochi Formation lies at an elevation of about 6,300 feet (1,920 m) to 6,600 feet (2,012 m) at the southeast of the Colorado Plateau; the deposits are from Hopi Lake, and the deposits extend southwards to the region at the north perimeter of the White Mountains of central-east Arizona. Bidahochi Lake is thought to have been a single "large lake, or several shallow, and ephemeral ones." Various fossil types are found; also bird trackways.
The White Rim Sandstone is a sandstone geologic formation located in southeastern Utah. It is the last member of the Permian Cutler Group, and overlies the major Organ Rock Formation and Cedar Mesa Sandstone; and again overlies thinner units of the Elephant Canyon and Halgaito Formations.
The Shinarump Conglomerate is a geologic formation found in the Four Corners region of the United States. It was deposited in the early part of the Late Triassic period.
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. The Hermit Formation varies in thickness from about 100 feet (30 m) in the eastern part of the Grand Canyon region to about 900 feet (270 m) in the region of Toroweap and Shivwits Plateaus. In the Sedona, Arizona area, it averages 300 feet (91 m) in thickness. The upper contact of the Hermit Formation is typically sharp and lacks gradation of any kind. The lower contact is a disconformity characterized by a significant amount of erosional relief, including paleovalleys as much as 60 feet (18 m) deep.
The Bluewater Creek Formation is a geologic formation in west-central New Mexico. It preserves fossils dating back to the late Triassic period.
The Petrified Forest Member is a stratigraphic unit of the Chinle Formation in Arizona, Colorado, New Mexico, Nevada, and Utah. It preserves fossils dating back to the Triassic period.
The Poleo Formation is a geologic formation in northern New Mexico. Its stratigraphic position corresponds to the late Triassic epoch.
Owl Rock is a 6,547-foot (1,996 m) elevation sandstone summit located south of Monument Valley, in northeast Arizona. It is situated 7 miles (11 km) north of Kayenta on Navajo Nation land, and can be seen from Highway 163 perched on the east edge of Tyende Mesa, where it towers 1,000 feet above the surrounding terrain. Its nearest higher neighbor is Agathla Peak, 1.4 miles (2.3 km) to the east-northeast, on the opposite side of this highway. Precipitation runoff from this feature drains into El Capitan Wash, which is part of the San Juan River drainage basin. The first ascent of Owl Rock was made in April 1966 by Fred Beckey and Harvey Carter by climbing cracks on the west face, and then bolting up a smooth south nose to the summit. They employed 20 pitons and 14 bolts on this route called Warpath. The descriptive name stems from its uncanny resemblance to an owl when viewed from the east. This feature is known as Bee 'Adizí in Navajo language meaning "spindle", and this sacred place is considered to be a spindle left behind by the Holy People. A newer name for it is Tsé Ts'óózí, meaning "Slim Rock".
Puercosuchus is an extinct genus of azendohsaurid archosauromorph from the Blue Mesa Member of the Chinle Formation in Arizona. The genus contains a single species, Puercosuchus traverorum, known from a bonebed of at least eight individuals.
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