Ocate volcanic field

Last updated
Ocate volcanic field
Wagonmound.jpg
Wagon Mound, a volcanic neck of the Ocate volcanic field
Highest point
Elevation 1,800 to 3,000 meters (5,900 to 9,800 ft) [1]
Coordinates 36°07′N104°45′W / 36.12°N 104.75°W / 36.12; -104.75 Coordinates: 36°07′N104°45′W / 36.12°N 104.75°W / 36.12; -104.75 [1]
Geography
Location Mora County, New Mexico,
United States
Geology
Age of rock 8.3 - 0.8 million years [1]
Mountain type Volcanic field

The Ocate volcanic field (also known as the Mora volcanic field) is a monogenetic volcanic field that extends from the southern Cimarron Range of the Sangre de Cristo Mountains to the vicinity of Wagon Mound, New Mexico. [2] The town of Wagon Mound is named after The Wagon Mound, a prominent landmark that is a highly eroded volcanic neck of the volcanic field. [3]

Contents

Description

About 8.12 million years ago, basaltic volcanoes began to erupt in the Ocate area. Fourteen eruptive pulses have been identified using Ar-Ar dating, with the most recent taking place around 0.67 to 0.95 Mya. [4] [5]

The lavas erupted in the field are mostly alkali olivine basalt or transitional olivine basalt, with smaller quantities of basaltic andesites, olivine andesites, and dacites. The basaltic lavas were generated from heterogeneous source regions in the mantle, while the more silica-rich andesites and dacites formed from fractional crystallization of basaltic magma and mixing with silica-rich magma from partial melting of crust. [6]

The volcanic field lies along the Jemez Lineament, a zone of young volcanic activity stretching from central Arizona to northeastern New Mexico. The lineament is thought to be a zone of weakness in the lower crust and upper mantle. The vents in the eastern part of the field are aligned roughly east to west, perpendicular to the direction of least compression in the southern Great Plains. Vents in the western part of the field are aligned more randomly, probably because of recent tectonic disturbance of this area. [5]

An unusual feature of the Ocate volcanic field is that the oldest basaltic flows form the highest mesas, and the youngest flows form surfaces lower in elevation. This reverse stratigraphy occurred because after the older flows were erupted about 8.3–5.7 m.y. ago on a relatively flat alluvial plain, the entire area was uplifted, and canyons were cut into the older basalt flows. Younger basalt flows then filled the major stream canyons. When uplift ceased, the youngest basalt flows of the Ocate volcanic field flowed on top of intermediate-aged flows. [4] [5]

History of investigation

During the Wheeler Survey of 1878 to 1879, J.J. Stevenson studied the basalt flows of the Ocate volcanic field, giving the name Ocate Mesa to the main lava-capped mesa that nearly surrounds the town of Ocate, New Mexico. Stevenson also recognized that the basalt-capped mesas south of Ocate Mesa were once continuous with Ocate Mesa prior to erosion. N.H. Darton included the outline of the field in his geologic map of New Mexico in 1928. More detailed mapping took place from the 1950s on. In 1988, J. Michael O'Neill and Harald H. Mehnert carried out the first detailed geologic study of the area and gave it the name of the Ocate volcanic field. [7]

See also

Footnotes

Related Research Articles

Extrusive rock Mode of igneous volcanic rock formation

Extrusive rock refers to the mode of igneous volcanic rock formation in which hot magma from inside the Earth flows out (extrudes) onto the surface as lava or explodes violently into the atmosphere to fall back as pyroclastics or tuff. In contrast, intrusive rock refers to rocks formed by magma which cools below the surface.

Mount Mazama Complex volcano in the Cascade Range

Mount Mazama is a complex volcano in the state of Oregon, United States, in a segment of the Cascade Volcanic Arc and Cascade Range. Most of the mountain collapsed following a major eruption approximately 7,700 years ago. The volcano is in Klamath County, in the southern Cascades, 60 miles (97 km) north of the Oregon–California border. Its collapse formed a caldera that holds Crater Lake. The mountain is in Crater Lake National Park. Mount Mazama originally had an elevation of 12,000 feet (3,700 m), but following its climactic eruption this was reduced to 8,157 feet (2,486 m). Crater Lake is 1,943 feet (592 m) deep, the deepest freshwater body in the US and the second deepest in North America after Great Slave Lake in Canada.

Mount Washington (Oregon) Deeply eroded volcano in the Cascade Range of Oregon

Mount Washington is a deeply eroded volcano in the Cascade Range of Oregon. It lies within Deschutes and Linn counties and is surrounded by the Mount Washington Wilderness area.

Medicine Lake Volcano

Medicine Lake Volcano is a large shield volcano in northeastern California about 30 mi (50 km) northeast of Mount Shasta. The volcano is located in a zone of east-west crustal extension east of the main axis of the Cascade Volcanic Arc and the Cascade Range. The 0.6 mi (1 km) thick shield is 22 mi (35 km) from east to west and 28 to 31 mi from north to south, and covers more than 770 sq mi (2,000 km2). The underlying rock has downwarped by 0.3 mi (0.5 km) under the center of the volcano. The volcano is primarily composed of basalt and basaltic andesite lava flows, and has a 4.3 by 7.5 mi caldera at the center.

Mount Tehama Eroded Andesitic stratovolcano in Northern California

Mount Tehama is an eroded andesitic stratovolcano in the Cascade Volcanic Arc and the Cascade Range in Northern California. Part of the Lassen volcanic area, its tallest remnant, Brokeoff Mountain, is itself the second highest peak in Lassen Volcanic National Park and connects to the park's highest point, Lassen Peak. Located on the border of Tehama County and Shasta County, Brokeoff's peak is the highest point in the former. The hikers that summit this mountain each year are treated to "exceptional" views of Lassen Peak, the Central Valley of California, and many of the park's other features. On clear days, Mount Shasta can also be seen in the distance.

Taos Plateau volcanic field Volcanic field in New Mexico and Colorado

The Taos Plateau volcanic field is an area of extensive volcanism in Taos County, New Mexico, United States. It is the largest volcanic field in the Rio Grande Rift, spreading over 7,000 square kilometers (2,700 sq mi). The total erupted volume is estimated at 420 cubic kilometers (100 cu mi). The age of most of the vents and associated lava flows in the field is estimated to be between 1.8 and 4 million years, with a few 22-million-year-old vents. The composition of the lavas varies from tholeiitic basalt to rhyolite. Landforms include sheet flows, cinder cones, and shield volcanoes. The sheet flows of the Servilleta Basalt are well-exposed in the Rio Grande Gorge carved by the Rio Grande. The highest point of the field is San Antonio Mountain at 10,908 feet (3,325 m).

Mount Taylor (New Mexico) Stratovolcano in the San Mateo Mountains, North America

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.

La Garita Caldera Large supervolcanic caldera in the state of Colorado, U.S.

La Garita Caldera is a large supervolcanic caldera in the San Juan volcanic field in the San Juan Mountains near the town of Creede in southwestern Colorado, United States. It is west of La Garita, Colorado. The eruption that created the La Garita Caldera is among the largest known volcanic eruptions in Earth's history, as well as being one of the most powerful known supervolcanic events.

Nevado de Longaví Volcano in Chile

Nevado de Longaví is a volcano in the Andes of central Chile. The 3,242 m (10,636 ft) high volcano lies in the Linares Province, which is part of the Maule Region. It features a summit crater and several parasitic vents. The volcano is constructed principally from lava flows. Two collapses of the edifice have carved collapse scars into the volcano, one on the eastern slope known as Lomas Limpias and another on the southwestern slope known as Los Bueye. The volcano features a glacier and the Achibueno and Blanco rivers originate on the mountain.

West Crater Lava dome in Washington, United States

West Crater is a small lava dome with associated lava flows in southern Washington, United States. Located in Skamania County, it rises to an elevation of 4,131 feet (1,259 m), and forms part of the Cascade Volcanic Arc. It is also part of the Marble Mountain-Trout Creek Hill volcanic field, a little-known Quaternary volcanic field in the southern Cascades of Washington state. The area can be hiked, and can be accessed by roads in the Gifford Pinchot National Forest.

Raton-Clayton volcanic field Volcanic field in New Mexico, United States

The Raton-Clayton volcanic field is a volcanic field located in the state of New Mexico, United States. Capulin Volcano National Monument is located in the volcanic field. It is the northeasternmost volcanic field of the Jemez Lineament and the easternmost Cenozoic volcanic field of North America.

Cat Hills volcanic field

Cat Hills volcanic field is a monogenetic volcanic field located in New Mexico, US.

Red Hill volcanic field Volcanic field in New Mexico, United States

Red Hill volcanic field, also known as Quemado volcanic field, is a monogenetic volcanic field located in the vicinity of the ghost town of Red Hill in Catron County New Mexico. Red Hill is 24 kilometers (15 mi) east of the larger Springerville volcanic field and includes Zuñi Salt Lake. The area is made up of scoria cone and silicic dome fields. Over 40 volcanic vents have been identified in the field. These erupted basaltic flows, with no other rock types evident in the field.

Western Cascades Region of Oregon, United States

The Western Cascades is a region of the U.S. state of Oregon between the Willamette Valley and the High Cascades. Deposits of Western Cascades age are also found in adjacent southwest Washington state. The range contains many extinct shield volcanoes, cinder cones and lava flows. The range is highly eroded and heavily forested.

Canadian Cascade Arc Canadian segment of the North American Cascade Volcanic Arc

The Canadian Cascade Arc, also called the Canadian Cascades, is the Canadian segment of the North American Cascade Volcanic Arc. Located entirely within the Canadian province of British Columbia, it extends from the Cascade Mountains in the south to the Coast Mountains in the north. Specifically, the southern end of the Canadian Cascades begin at the Canada–United States border. However, the specific boundaries of the northern end are not precisely known and the geology in this part of the volcanic arc is poorly understood. It is widely accepted by geologists that the Canadian Cascade Arc extends through the Pacific Ranges of the Coast Mountains. However, others have expressed concern that the volcanic arc possibly extends further north into the Kitimat Ranges, another subdivision of the Coast Mountains, and even as far north as Haida Gwaii.

Mount Cayley volcanic field Remote volcanic zone in Canada

The Mount Cayley volcanic field (MCVF) is a remote volcanic zone on the South Coast of British Columbia, Canada, stretching 31 km (19 mi) from the Pemberton Icefield to the Squamish River. It forms a segment of the Garibaldi Volcanic Belt, the Canadian portion of the Cascade Volcanic Arc, which extends from Northern California to southwestern British Columbia. Most of the MCVF volcanoes were formed during periods of volcanism under sheets of glacial ice throughout the last glacial period. These subglacial eruptions formed steep, flat-topped volcanoes and subglacial lava domes, most of which have been entirely exposed by deglaciation. However, at least two volcanoes predate the last glacial period and both are highly eroded. The field gets its name from Mount Cayley, a volcanic peak located at the southern end of the Powder Mountain Icefield. This icefield covers much of the central portion of the volcanic field and is one of the several glacial fields in the Pacific Ranges of the Coast Mountains.

Sand Mountain Volcanic Field Volcanic field in Oregon

The Sand Mountain Volcanic Field is a volcanic field in the upper McKenzie River watershed, located in the United States in Oregon. Part of the Cascade Volcanic Arc, it lies southwest of Mount Jefferson and northwest of Belknap Crater and Mount Washington. Its highest elevation is 5,463 feet (1,665 m).

Polvadera Group A group of geologic formations in New Mexico

The Polvadera Group is a group of geologic formations exposed in and around the Jemez Mountains of northern New Mexico. Radiometric dating gives it an age of 13 to 2.2 million years, corresponding to the Miocene through early Quaternary.

Servilleta Basalt

The Servilleta Basalt or Servilleta Formation is a geologic formation that underlies most of the Taos Plateau of northern New Mexico. It has a radiometric age of 3.6 to 4.5 million years, corresponding to the Pliocene epoch.

The Bearwallow Mountain Andesite or Bearwallow Mountain Formation is a geologic formation exposed in and around the Mogollon Mountains of southwest New Mexico. It has a radiometric age of 27 to 23 million years, corresponding to the late Oligocene to early Miocene epochs.

References