The geology of the Zion and Kolob canyons area includes nine known exposed formations, all visible in Zion National Park in the U.S. state of Utah. Together, these formations represent about 150 million years of mostly Mesozoic-aged sedimentation in that part of North America. Part of a super-sequence of rock units called the Grand Staircase, the formations exposed in the Zion and Kolob area were deposited in several different environments that range from the warm shallow seas of the Kaibab and Moenkopi formations, streams and lakes of the Chinle, Moenave, and Kayenta formations to the large deserts of the Navajo and Temple Cap formations and dry near shore environments of the Carmel Formation.
The Colorado Plateau, also known as the Colorado Plateau Province, is a physiographic and desert region of the Intermontane Plateaus, roughly centered on the Four Corners region of the southwestern United States. This province covers an area of 336,700 km2 (130,000 mi2) within western Colorado, northwestern New Mexico, southern and eastern Utah, northern Arizona, and a tiny fraction in the extreme southeast of Nevada. About 90% of the area is drained by the Colorado River and its main tributaries: the Green, San Juan, and Little Colorado. Most of the remainder of the plateau is drained by the Rio Grande and its tributaries.
A maar is a broad, low-relief volcanic crater caused by a phreatomagmatic eruption. A maar characteristically fills with water to form a relatively shallow crater lake, which may also be called a maar. The name comes from a Moselle Franconian dialect word used for the circular lakes of the Daun area of Germany.
The San Francisco Peaks are a volcanic mountain range in the San Francisco volcanic field in north central Arizona, just north of Flagstaff and a remnant of the former San Francisco Mountain. The highest summit in the range, Humphreys Peak, is the highest point in the state of Arizona at 12,633 feet (3,851 m) in elevation. The San Francisco Peaks are the remains of an eroded stratovolcano. An aquifer within the caldera supplies much of Flagstaff's water while the mountain itself is in the Coconino National Forest, a popular recreation site. The Arizona Snowbowl ski area is on the western slopes of Humphreys Peak, and has been the subject of major controversy involving several tribes and environmental groups.
Northern Arizona is an unofficial, colloquially-defined region of the U.S. state of Arizona. Generally consisting of Apache, Coconino, Mohave, Navajo, and Gila counties, the region is geographically dominated by the Colorado Plateau, the southern border of which in Arizona is called the Mogollon Rim.
Mount Taylor is a dormant stratovolcano in northwest New Mexico, northeast of the town of Grants. It is the high point of the San Mateo Mountains and the highest point in the Cibola National Forest.
Fort Rock is a tuff ring located on an ice age lake bed in north Lake County, Oregon, United States. The ring is about 4,460 feet (1,360 m) in diameter and stands about 200 feet (60 m) high above the surrounding plain. Its name is derived from the tall, straight sides that resemble the palisades of a fort. The region of Fort Rock–Christmas Lake Valley basin contains about 40 such tuff rings and maars and is located in the Brothers Fault Zone of central Oregon's Great Basin. William Sullivan, an early settler in the area, named Fort Rock in 1873 while searching for lost cattle.
Hole-in-the-Ground is a large maar in the Fort Rock–Christmas Lake Valley basin of Lake County, central Oregon, northeast of Crater Lake, near Oregon Route 31.
Volcanic activity is a major part of the geology of Canada and is characterized by many types of volcanic landform, including lava flows, volcanic plateaus, lava domes, cinder cones, stratovolcanoes, shield volcanoes, submarine volcanoes, calderas, diatremes, and maars, along with less common volcanic forms such as tuyas and subglacial mounds.
The Buffalo Head Hills kimberlite field is a group of kimberlitic volcanic pipes or diatremes in north-central Alberta, Canada. As of 2011, 41 kimberlite pipes, of which 28 are diamondiferous, had been identified in the field. They were emplaced during Late Cretaceous to early Paleocene time.
The northern Alberta kimberlite province (NAKP) consists of three groups of diatremes or volcanic pipes in north-central Alberta, Canada, most of which are kimberlites and some of which are diamondiferous. They are called the Birch Mountains (BM), Buffalo Head Hills (BHH), and the Mountain Lake cluster (ML), and they were discovered between about 1990 and 1997. Most of the diatremes were emplaced during the Late Cretaceous Epoch although a few are as young as early Paleocene.
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 Pali-Aike volcanic field is a volcanic field along the Argentina–Chile border. It is part of a family of back-arc volcanoes in Patagonia, which formed from processes involving the collision of the Chile Ridge with the Peru–Chile Trench. It lies farther east than the Austral Volcanic Zone, the volcanic arc that makes up the Andean Volcanic Belt at this latitude. Pali-Aike formed over sedimentary rock of Magallanes Basin, a Jurassic-age basin starting from the late Miocene as a consequence of regional tectonic events.
The geology of South Dakota began to form more than 2.5 billion years ago in the Archean eon of the Precambrian. Igneous crystalline basement rock continued to emplace through the Proterozoic, interspersed with sediments and volcanic materials. Large limestone and shale deposits formed during the Paleozoic, during prevalent shallow marine conditions, followed by red beds during terrestrial conditions in the Triassic. The Western Interior Seaway flooded the region, creating vast shale, chalk and coal beds in the Cretaceous as the Laramide orogeny began to form the Rocky Mountains. The Black Hills were uplifted in the early Cenozoic, followed by long-running periods of erosion, sediment deposition and volcanic ash fall, forming the Badlands and storing marine and mammal fossils. Much of the state's landscape was reworked during several phases of glaciation in the Pleistocene. South Dakota has extensive mineral resources in the Black Hills and some oil and gas extraction in the Williston Basin. The Homestake Mine, active until 2002, was a major gold mine that reached up to 8000 feet underground and is now used for dark matter and neutrino research.
The Salton Buttes are a group of volcanoes in California, on the Salton Sea. They consist of a 7-kilometer (4.3 mi)-long row of five lava domes, named Mullet Island, North Red Hill, Obsidian Butte, Rock Hill and South Red Hill. They are closely associated with a fumarolic field and a geothermal field, and there is evidence of buried volcanoes underground. In pre-modern times Obsidian Butte was an important regional source of obsidian.
The geology of North Dakota includes thick sequences oil and coal bearing sedimentary rocks formed in shallow seas in the Paleozoic and Mesozoic, as well as terrestrial deposits from the Cenozoic on top of ancient Precambrian crystalline basement rocks. The state has extensive oil and gas, sand and gravel, coal, groundwater and other natural resources.
A volcanic crater lake is a lake in a crater that was formed by explosive activity or a collapse during a volcanic eruption.
Cathedral Cliff is a 5,810-foot elevation volcanic plug located on Navajo Nation land in San Juan County of northwest New Mexico, United States. It is a prominent landmark set alongside U.S. Route 491, approximately 13 miles south of the community of Shiprock, New Mexico. Cathedral Cliff is one of the phreatomagmatic diatremes of the Four Corners area, and with significant relief as it rises 400 feet above the high-desert plain. It is situated about 9.5 miles (15.3 km) southeast of Shiprock, the most famous of these diatremes. Cathedral Cliff is set in the northeastern part of the Navajo Volcanic Field, a volcanic field that includes intrusions and flows of minette and other unusual igneous rocks which formed around 30 million years ago during the Oligocene. Its nearest higher neighbor is Table Mesa, one mile to the southwest, and Barber Peak is set 1.5 mile to the southeast.
The Navajo volcanic field is a monogenetic volcanic field located in the Four Corners region of the United States, in the central part of the Colorado Plateau. The volcanic field consists of over 80 volcanoes and associated intrusions of unusual potassium-rich compositions, with an age range of 26.2 to 24.7 million years (Ma).
