| Manzaz volcanic field | |
|---|---|
 Manzaz seen from space | |
| Highest point | |
| Elevation | 1,672 m (5,486 ft) [1] |
| Coordinates | 23°55′N5°50′E / 23.92°N 5.83°E [1] |
| Geography | |
  Manzaz volcanic field | |
Manzaz volcanic field is a volcanic field in Algeria. It consists of scoria cones with lava flows and has been active until recently.
The field lies in Hoggar, close to the Atakor volcanic field. [1] A dome-like uplift has been associated with the volcanism in the region. [2] The presence of volcanism has been explained by tectonic events associated with the collision between Europe and Africa, and the resulting reactivation of ancient tectonic lineaments. [3]
The field consists of scoria cones and covers a surface of 1,500 square kilometres (580 sq mi). Many of these have breaches [1] and are heavily eroded. The cones were strombolianically active [4] and have erupted lava flows. [1] Volcanic ash and pyroclastics are also found. [5] Some eruptions took place along fissure vents. Lava flows have surrounded older granite peaks. [6] Oukcem is a maar in the field [1] that consists of two separate craters with diameters of 500 metres (1,600 ft) and 700 metres (2,300 ft) respectively. They are surrounded by tuffs and natron is found at the bottom of the larger crater, [7] as the maar occasionally floods. [8] Local people use the natron. [9]
The basement consists of metamorphic and plutonic rocks of Precambrian age, which are part of the Tuareg shield [1] and of the LATEA metacraton. [6] They form a 1,000 kilometres (620 mi) wide uplift of unclear origin in the Hoggar. [10] Outcrops of granite are found in some places. [11] These were first buried by tholeiitic basalts between 35 and 30 million years ago. [2]
The field has mostly erupted basalt and basanite, [12] with rarer trachyandesite and trachybasalt. [13] Xenoliths include peridotite and pyroxenite, [1] and amphibole and feldspar form megacrysts in the rocks. [4] Xenoliths appear to, in part, originate from a metasomatized mantle. [14] The total volume of erupted rocks is about 175 cubic kilometres (42 cu mi). [15]
Three phases of volcanic activity have been distinguished at Manzaz, the first between 20 and 12 million years ago, the second between 7 and 4 million years ago and the third between 3 and 0.01 million years ago. [15] Only one precise date is known, 1.51±0.85 million years. [10] Volcanic activity continued into the Holocene. Some young volcanoes developed on terraces of Neolithic age [1] or have a young, uneroded appearance. [16]
Antofagasta de la Sierra is a volcanic field in Argentina. The main type of volcanic edifice in the area are scoria cones, it is formed by the La Laguna, Jote and Alumbrera volcanoes. The first and last of these form a sub-group which is better researched. Various dating methods have yielded ages from several million to several hundred thousand years ago, but some vents appear to be of Holocene age.
The Potrillo volcanic field is a monogenetic volcanic field located on the Rio Grande Rift in southern New Mexico, United States and northern Chihuahua, Mexico. The volcanic field lies 22 miles (35 km) southwest of Las Cruces, and occupies about 4,600 square kilometers (1,800 sq mi) near the U.S. border with Mexico.
El Negrillar is a volcanic field in the Andes. Located south of the Salar de Atacama and west of the Cordón de Púlar, it generated cinder cones and lava flows. Covering a surface area of 220 square kilometres (85 sq mi), it is the largest volcanic field in northern Chile, with almost a hundred vents that produced mainly lava flows. Owing to the arid climate, landforms are well preserved. Radiometric dating has yielded ages of less than 1.5 million years, with the most recent eruption occurring about 141,000 years ago. Parts of the Holocene Socompa debris avalanche overlie the field. A groundwater system underlies the volcanic field and some cones formed through phreatomagmatic eruptions. El Negrillar is located in a complex tectonic regime, characterized by numerous faults. The town of Tilomonte and various power lines, mines and water wells are in the area.
Cerro Bitiche is a volcanic field in Argentina. It is located east of the Central Volcanic Zone away from the volcanic arc within the Altiplano-Puna volcanic complex (APVC), close to Zapaleri volcano.
Cerro Morado is a monogenetic volcanic field, in Argentina. It is part of a group of mafic volcanic centres in the Altiplano-Puna region, which is dominated by silicic rocks such as dacitic - rhyolitic rocks.
Aluchin is a volcano along the Aluchin River in the Chukotka Autonomous Okrug of Russia. The volcano was discovered in 1956–1957 by G.K. Kleshchev.
Azas Plateau is a volcanic field in Russia. It is also known as East Tuva Plateau, Khamsara-Biykhem Plateau and Northeast Tuva Plateau. It covers a surface area of 2,000 square kilometres (770 sq mi) west of Lake Baikal. Volcanic activity in the area also occurred at the Oka Plateau and the Jom-Bolok volcanic field.
Longgang is a volcanic field in Jilin Province, China. It is also known as Chingyu, Longwan Group or Lung-wan Group. This volcanic field contains over 164 individual centres in the form of crater lakes, maars and volcanic cones and covers a surface area of 1,700 square kilometres (660 sq mi). The field is forested and mostly undisturbed by human activities.
Mascota volcanic field is a volcanic field in Mexico. It is formed by cinder cones and lava domes that lie 50 kilometres (31 mi) east of Puerto Vallarta. Several other volcanic fields lie in the neighbourhood.
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.
San Borja volcanic field is a volcanic field in Baja California, northeast of the Vizcaino Peninsula. It is formed by a plateau of lava flows and a number of scoria cones. The field started erupting over twelve million years ago and has endured several changes in regional tectonics.
Cima volcanic field is a volcanic field in San Bernardino County, California, close to the border with Nevada. The volcanic field covers a surface area of 600 km2 (230 sq mi) within the Mojave National Preserve west of the Cima Dome and consists of about 40 volcanic cones with about 60 lava flows. The volcanic cones range from simple cones over multi-cratered mountains to eroded hills, and lava flows are up to 9.1 km (5.7 mi) long. At least one lava tube exists in the field and can be visited.
Big Pine volcanic field is a volcanic field in Inyo County, California. The volcanic field covers a surface area of 500 square kilometres (190 sq mi) within the Owens Valley east of the Sierra Nevada and consists of lava flows, one rhyolitic coulee and about 40 volcanic vents including cinder cones. Some vents are simple conical cinder cones while others are irregular scoria cones. Glaciers and former lakes have modified lava flows.
Tahalra volcanic field is a volcanic field in Algeria. It consists of a Miocene lava plateau and a number of Pliocene to Holocene age individual vents, including cinder cones.
Meidob volcanic field is a Holocene volcanic field in Darfur, Sudan. It is one of several volcanic fields in Africa whose origin is explained by the activity of mantle plumes and their interaction with crustal structures. Meidob lies at the southern margin of the Sahara.
Gharyan volcanic field is a volcanic field in northwestern Libya, with the towns of Bani Walid, Gharyan, Mizdah and Tarhunah close by.
Atakor volcanic field is a volcanic field in Algeria. It lies in the Hoggar mountains and consists of a variety of volcanic features such as lava flows and about 450 individual vents which create a spectacular scenery.
Bayuda volcanic field is a volcanic field in Sudan, within the Bayuda Desert. It covers a surface of about 11 by 48 kilometres and consists of a number of cinder cones as well as some maars and explosion craters. These vents have erupted 'A'ā lava flows.
Lunar Crater volcanic field is a volcanic field in Nye County, Nevada. It lies along the Reveille and Pancake Ranges and consists of over 200 vents, mostly small volcanic cones with associated lava flows but also several maars, including one maar named Lunar Crater. Some vents have been eroded so heavily that the structures underneath the volcanoes have been exposed. Lunar Crater itself has been used as a testing ground for Mars rovers and as training ground for astronauts.
Pasto Ventura is an area in the Catamarca Province of Argentina. It features about 14 small Pleistocene volcanoes, mostly cinder cones with associated lava flows but also lava domes, tuff rings and two maars. The volcanoes are accompanied by pyroclastic deposits and their total volume reaches about 0.42 cubic kilometres (0.10 cu mi). Argon-argon dating has yielded ages ranging from 1.3 million years to about 270,000 years for volcanic rocks in the field.
| Authority control databases: Geographic |
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