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Le Qiao - One of the best experts on this subject based on the ideXlab platform.
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The Cauchy 5 Small, Low‐Volume Lunar Shield Volcano: Evidence for Volatile Exsolution‐Eruption Patterns and Type 1/Type 2 Hybrid Irregular Mare Patch Formation
Journal of Geophysical Research: Planets, 2020Co-Authors: Le Qiao, Lionel Wilson, James W. Head, Zongcheng LingAbstract:The lunar Shield Volcano Cauchy 5, sitting at the low diameter‐height‐volume end of the population, is the only known example containing two different types of Irregular Mare Patches (IMPs) in very close association: (1) the pit crater interior Type 1 IMP composed of bleb‐like mounds surrounded by a hummocky and blocky floor unit and (2) Type 2 IMPs, small, often optically immature pits less than ~5 m deep, located on the generally block‐deficient Shield flanks. A four‐phase lunar magma ascent/eruption model predicts that during a relatively brief eruption, low magma rise rates maximize volatile exsolution in lava filling the pit crater. Bubble‐rich magmas overtop the pit crater and form extremely vesicular flows on the Shield flanks. Exposure of the flanking flows to vacuum produces a fragmental layer of exploded glassy bubble walls. Subsequent second boiling upon cooling of the flanking flow interiors releases additional volatiles which migrate and collect, forming magmatic foams and gas pockets. As magma rise rates slow, trapped gas and magmatic foam build up below the cooling pit crater floor. Magmatic foams are extruded to form Type 1 IMP deposits. Type 2 IMPs on the flanks are interpreted to be due primarily to subsequent impacts causing collapse of the flow surface layer into the extremely vesicle‐ and void‐rich flow interior. Anomalously young pit crater floor/Shield flank crater retention ages compared with surrounding maria ages may be due to effects of Cauchy 5 substrate characteristics (extreme micro‐ and macroporosity, foamy nature, and glassy auto‐regolith) on superposed crater formation and retention.
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the cauchy 5 small low volume lunar Shield Volcano evidence for volatile exsolution eruption patterns and type 1 type 2 hybrid irregular mare patch formation
Journal of Geophysical Research, 2020Co-Authors: Le Qiao, Lionel Wilson, J W Head, Zongcheng LingAbstract:The lunar Shield Volcano Cauchy 5, sitting at the low diameter‐height‐volume end of the population, is the only known example containing two different types of Irregular Mare Patches (IMPs) in very close association: (1) the pit crater interior Type 1 IMP composed of bleb‐like mounds surrounded by a hummocky and blocky floor unit and (2) Type 2 IMPs, small, often optically immature pits less than ~5 m deep, located on the generally block‐deficient Shield flanks. A four‐phase lunar magma ascent/eruption model predicts that during a relatively brief eruption, low magma rise rates maximize volatile exsolution in lava filling the pit crater. Bubble‐rich magmas overtop the pit crater and form extremely vesicular flows on the Shield flanks. Exposure of the flanking flows to vacuum produces a fragmental layer of exploded glassy bubble walls. Subsequent second boiling upon cooling of the flanking flow interiors releases additional volatiles which migrate and collect, forming magmatic foams and gas pockets. As magma rise rates slow, trapped gas and magmatic foam build up below the cooling pit crater floor. Magmatic foams are extruded to form Type 1 IMP deposits. Type 2 IMPs on the flanks are interpreted to be due primarily to subsequent impacts causing collapse of the flow surface layer into the extremely vesicle‐ and void‐rich flow interior. Anomalously young pit crater floor/Shield flank crater retention ages compared with surrounding maria ages may be due to effects of Cauchy 5 substrate characteristics (extreme micro‐ and macroporosity, foamy nature, and glassy auto‐regolith) on superposed crater formation and retention.
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geological characterization of the ina Shield Volcano summit pit crater on the moon evidence for extrusion of waning stage lava lake magmatic foams and anomalously young crater retention ages
Journal of Geophysical Research, 2019Co-Authors: Le Qiao, Lionel Wilson, James W. Head, Long Xiao, Zongcheng Ling, Josef DufekAbstract:Ina, a distinctive ~2 × 3 km D-shaped depression, is composed of unusual bulbous-shaped mounds surrounded by optically immature hummocky/blocky floor units. The crisp appearance, optical immaturity, and low number of superposed impact craters combine to strongly suggest a geologically recent formation for Ina, but the specific formation mechanism remains controversial. We reconfirm that Ina is a summit pit crater/vent on a small Shield Volcano ~3.5 billion years old. Following detailed characterization, we interpret the range of Ina characteristics to be consistent with a two-component model of origin during the waning stages of summit pit eruption activities. The Ina pit crater floor is interpreted to be dominated by the products of late-stage, low-rise rate magmatic dike emplacement. Magma in the dike underwent significant shallow degassing and vesicle formation, followed by continued degassing below the solidified and highly microvesicular and macrovesicular lava lake crust, resulting in cracking of the crust and extrusion of gas-rich magmatic foams onto the lava lake crust to form the mounds. These unique substrate characteristics (highly porous aerogel-like foam mounds and floor terrains with large vesicles and void space) exert important effects on subsequent impact crater characteristics and populations, influencing (1) optical maturation processes, (2) regolith development, and (3) landscape evolution by modifying the nature and evolution of superposed impact craters and thus producing anomalously young crater retention ages. Accounting for these effects results in a shift of crater size-frequency distribution model ages from
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ina pit crater on the moon extrusion of waning stage lava lake magmatic foam results in extremely young crater retention ages
Geology, 2017Co-Authors: Le Qiao, Lionel Wilson, James W. Head, Long Xiao, M A Kreslavsky, Josef DufekAbstract:The enigmatic Ina feature on the Moon was recently interpreted to represent extrusive basaltic volcanic activity within the past 100 m.y. of lunar history, an extremely young age for volcanism on the Moon. Ina is a 2 × 3 km D-shaped depression that consists of a host of unusual bleb-like mounds surrounded by a relatively optically fresh hummocky and blocky floor. Documentation of magmatic-volcanic processes from Shield Volcano summit pit craters in Hawai’i and new insights into Shield-building and dike evolution processes on the Moon provide important perspectives on the origin of Ina. We show that the size, location, morphology, topography, and optical maturity of Ina are consistent with an origin as a subsided summit pit crater lava lake on top of a broad ~22-km-diameter, ~3.5-b.y.-old Shield Volcano. New theoretical treatments of lunar Shield-building magmatic dike events predict that waning-stage summit activity was characterized by the production of magmatic foam in the dike and lake; the final stages of dike stress relaxation and closure cause the magmatic foam to extrude to the surface through cracks in the lava lake crust to produce the mounds. The high porosity of the extruded foams (>75%) altered the nature of subsequent impact craters (the aerogel effect), causing them to be significantly smaller in diameter, which could bias the crater-derived model ages. Accounting for this effect allows for significantly older model ages, to ~3.5 b.y., contemporaneous with the underlying Shield Volcano. Thus extremely young volcanic eruptions are not required to explain the unusual nature of Ina.
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density and lithospheric thickness of the marius hills Shield Volcano on the moon
Scientia Sinica Physica Mechanica & Astronomica, 2013Co-Authors: Qian Huang, Le Qiao, Long Xiao, Jinsong Ping, Zhiyong Xiao, Jiannan ZhaoAbstract:Marius Hills is a large volcanic complex on the Oceans Procellarum of the lunar nearside. Numerous volcanic features, including domes, cones, and rilles occur in this region. Due to limitations in lunar remote sensing data, most previous studies on this region focused on its morphological and geochemical properties but little was known about the subsurface and interior structures of this volcanic complex. Knowledge of the local crustal density is meaningful to both determine the composition for this volcanic complex and understand the crustal evolutionary history for this region. Constraining the lithospheric thickness in this region is helpful to estimate the heat flux at the time of volcanic loading, which is a crucial parameter to study the thermal evolutionary history of the nearside mantle. Here, we applied a localized gravity and topography admittance analysis for the Marius Hills region to constraint its crustal density and lithospheric thickness. The gravity filed is modeled using a thin elastic lithspheric model that considers both surface and subsurface loads. Localized admittance and correlations spectra are used to constrain these modeled parameters. The best-fit crustal density in our model is ~3040 kg m-3, which is much higher than the average lunar crustal density as 2550 kg m-3, indicating that magma chambers or sills has intruded to the shallow crust and/or that intrusive magma has filled up the porous subsurface crust. The total volume of basalts emplaced in the Marius Hills region is ~2.9×104 km3, suggesting that Marius Hills is a major volcanic center in the Oceanus Procellarum. The best-fit lithospheric thickness of this region is constrained to be as small as ~4 km, indicating that a significant amount of heat production elements have concentrated in this region during the formation of the volcanic complex. This result is consistent with the previous spectral studies that heat production elements (such as thorium) are more abundant in the Oceanus Procellarum.
Lionel Wilson - One of the best experts on this subject based on the ideXlab platform.
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The Cauchy 5 Small, Low‐Volume Lunar Shield Volcano: Evidence for Volatile Exsolution‐Eruption Patterns and Type 1/Type 2 Hybrid Irregular Mare Patch Formation
Journal of Geophysical Research: Planets, 2020Co-Authors: Le Qiao, Lionel Wilson, James W. Head, Zongcheng LingAbstract:The lunar Shield Volcano Cauchy 5, sitting at the low diameter‐height‐volume end of the population, is the only known example containing two different types of Irregular Mare Patches (IMPs) in very close association: (1) the pit crater interior Type 1 IMP composed of bleb‐like mounds surrounded by a hummocky and blocky floor unit and (2) Type 2 IMPs, small, often optically immature pits less than ~5 m deep, located on the generally block‐deficient Shield flanks. A four‐phase lunar magma ascent/eruption model predicts that during a relatively brief eruption, low magma rise rates maximize volatile exsolution in lava filling the pit crater. Bubble‐rich magmas overtop the pit crater and form extremely vesicular flows on the Shield flanks. Exposure of the flanking flows to vacuum produces a fragmental layer of exploded glassy bubble walls. Subsequent second boiling upon cooling of the flanking flow interiors releases additional volatiles which migrate and collect, forming magmatic foams and gas pockets. As magma rise rates slow, trapped gas and magmatic foam build up below the cooling pit crater floor. Magmatic foams are extruded to form Type 1 IMP deposits. Type 2 IMPs on the flanks are interpreted to be due primarily to subsequent impacts causing collapse of the flow surface layer into the extremely vesicle‐ and void‐rich flow interior. Anomalously young pit crater floor/Shield flank crater retention ages compared with surrounding maria ages may be due to effects of Cauchy 5 substrate characteristics (extreme micro‐ and macroporosity, foamy nature, and glassy auto‐regolith) on superposed crater formation and retention.
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the cauchy 5 small low volume lunar Shield Volcano evidence for volatile exsolution eruption patterns and type 1 type 2 hybrid irregular mare patch formation
Journal of Geophysical Research, 2020Co-Authors: Le Qiao, Lionel Wilson, J W Head, Zongcheng LingAbstract:The lunar Shield Volcano Cauchy 5, sitting at the low diameter‐height‐volume end of the population, is the only known example containing two different types of Irregular Mare Patches (IMPs) in very close association: (1) the pit crater interior Type 1 IMP composed of bleb‐like mounds surrounded by a hummocky and blocky floor unit and (2) Type 2 IMPs, small, often optically immature pits less than ~5 m deep, located on the generally block‐deficient Shield flanks. A four‐phase lunar magma ascent/eruption model predicts that during a relatively brief eruption, low magma rise rates maximize volatile exsolution in lava filling the pit crater. Bubble‐rich magmas overtop the pit crater and form extremely vesicular flows on the Shield flanks. Exposure of the flanking flows to vacuum produces a fragmental layer of exploded glassy bubble walls. Subsequent second boiling upon cooling of the flanking flow interiors releases additional volatiles which migrate and collect, forming magmatic foams and gas pockets. As magma rise rates slow, trapped gas and magmatic foam build up below the cooling pit crater floor. Magmatic foams are extruded to form Type 1 IMP deposits. Type 2 IMPs on the flanks are interpreted to be due primarily to subsequent impacts causing collapse of the flow surface layer into the extremely vesicle‐ and void‐rich flow interior. Anomalously young pit crater floor/Shield flank crater retention ages compared with surrounding maria ages may be due to effects of Cauchy 5 substrate characteristics (extreme micro‐ and macroporosity, foamy nature, and glassy auto‐regolith) on superposed crater formation and retention.
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geological characterization of the ina Shield Volcano summit pit crater on the moon evidence for extrusion of waning stage lava lake magmatic foams and anomalously young crater retention ages
Journal of Geophysical Research, 2019Co-Authors: Le Qiao, Lionel Wilson, James W. Head, Long Xiao, Zongcheng Ling, Josef DufekAbstract:Ina, a distinctive ~2 × 3 km D-shaped depression, is composed of unusual bulbous-shaped mounds surrounded by optically immature hummocky/blocky floor units. The crisp appearance, optical immaturity, and low number of superposed impact craters combine to strongly suggest a geologically recent formation for Ina, but the specific formation mechanism remains controversial. We reconfirm that Ina is a summit pit crater/vent on a small Shield Volcano ~3.5 billion years old. Following detailed characterization, we interpret the range of Ina characteristics to be consistent with a two-component model of origin during the waning stages of summit pit eruption activities. The Ina pit crater floor is interpreted to be dominated by the products of late-stage, low-rise rate magmatic dike emplacement. Magma in the dike underwent significant shallow degassing and vesicle formation, followed by continued degassing below the solidified and highly microvesicular and macrovesicular lava lake crust, resulting in cracking of the crust and extrusion of gas-rich magmatic foams onto the lava lake crust to form the mounds. These unique substrate characteristics (highly porous aerogel-like foam mounds and floor terrains with large vesicles and void space) exert important effects on subsequent impact crater characteristics and populations, influencing (1) optical maturation processes, (2) regolith development, and (3) landscape evolution by modifying the nature and evolution of superposed impact craters and thus producing anomalously young crater retention ages. Accounting for these effects results in a shift of crater size-frequency distribution model ages from
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ina pit crater on the moon extrusion of waning stage lava lake magmatic foam results in extremely young crater retention ages
Geology, 2017Co-Authors: Le Qiao, Lionel Wilson, James W. Head, Long Xiao, M A Kreslavsky, Josef DufekAbstract:The enigmatic Ina feature on the Moon was recently interpreted to represent extrusive basaltic volcanic activity within the past 100 m.y. of lunar history, an extremely young age for volcanism on the Moon. Ina is a 2 × 3 km D-shaped depression that consists of a host of unusual bleb-like mounds surrounded by a relatively optically fresh hummocky and blocky floor. Documentation of magmatic-volcanic processes from Shield Volcano summit pit craters in Hawai’i and new insights into Shield-building and dike evolution processes on the Moon provide important perspectives on the origin of Ina. We show that the size, location, morphology, topography, and optical maturity of Ina are consistent with an origin as a subsided summit pit crater lava lake on top of a broad ~22-km-diameter, ~3.5-b.y.-old Shield Volcano. New theoretical treatments of lunar Shield-building magmatic dike events predict that waning-stage summit activity was characterized by the production of magmatic foam in the dike and lake; the final stages of dike stress relaxation and closure cause the magmatic foam to extrude to the surface through cracks in the lava lake crust to produce the mounds. The high porosity of the extruded foams (>75%) altered the nature of subsequent impact craters (the aerogel effect), causing them to be significantly smaller in diameter, which could bias the crater-derived model ages. Accounting for this effect allows for significantly older model ages, to ~3.5 b.y., contemporaneous with the underlying Shield Volcano. Thus extremely young volcanic eruptions are not required to explain the unusual nature of Ina.
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Evidence for a sill emplacement event on the upper flanks of the Ascraeus Mons Shield Volcano, Mars
Journal of Geophysical Research: Planets, 1999Co-Authors: Evelyn D. Scott, Lionel WilsonAbstract:Channels within the SSW rift zone of Ascraeus Mons, a large Shield Volcano forming part of the Tharsis volcanic province on Mars, have morphological features extremely similar to those of channels identified elsewhere on Mars as being due to fluvial action. The channel sources are too far from the caldera rim and have the wrong morphology for it to be plausible that the channels were eroded during pyroclastic flow eruptions, and the sinuosities are not consistent with scenarios involving lava flows. We propose that these channels were formed by meltwater generated and released, mainly by relatively slow seepage, when a sill was emplaced within or beneath an ice-rich permafrost layer. Smaller, fan-like channels coalescing into the amphitheater headwall of the wider ones are secondary features produced by further sapping of the undermined flank. The minimum dimensions required for the sill (∼13 by 13 km in lateral extent and ∼120 m thick) are calculated using the thermal exchanges between the sill and the permafrost implied by the volumes of the channel head craters. The corresponding minimum sill volume, ∼19 km3, is similar to that df many surface lava flows associated with the Tharsis Shield Volcanoes and is of the order expected for an intrusion resulting from an elastic inflation-deflation event in the summit magma reservoir.
Zongcheng Ling - One of the best experts on this subject based on the ideXlab platform.
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The Cauchy 5 Small, Low‐Volume Lunar Shield Volcano: Evidence for Volatile Exsolution‐Eruption Patterns and Type 1/Type 2 Hybrid Irregular Mare Patch Formation
Journal of Geophysical Research: Planets, 2020Co-Authors: Le Qiao, Lionel Wilson, James W. Head, Zongcheng LingAbstract:The lunar Shield Volcano Cauchy 5, sitting at the low diameter‐height‐volume end of the population, is the only known example containing two different types of Irregular Mare Patches (IMPs) in very close association: (1) the pit crater interior Type 1 IMP composed of bleb‐like mounds surrounded by a hummocky and blocky floor unit and (2) Type 2 IMPs, small, often optically immature pits less than ~5 m deep, located on the generally block‐deficient Shield flanks. A four‐phase lunar magma ascent/eruption model predicts that during a relatively brief eruption, low magma rise rates maximize volatile exsolution in lava filling the pit crater. Bubble‐rich magmas overtop the pit crater and form extremely vesicular flows on the Shield flanks. Exposure of the flanking flows to vacuum produces a fragmental layer of exploded glassy bubble walls. Subsequent second boiling upon cooling of the flanking flow interiors releases additional volatiles which migrate and collect, forming magmatic foams and gas pockets. As magma rise rates slow, trapped gas and magmatic foam build up below the cooling pit crater floor. Magmatic foams are extruded to form Type 1 IMP deposits. Type 2 IMPs on the flanks are interpreted to be due primarily to subsequent impacts causing collapse of the flow surface layer into the extremely vesicle‐ and void‐rich flow interior. Anomalously young pit crater floor/Shield flank crater retention ages compared with surrounding maria ages may be due to effects of Cauchy 5 substrate characteristics (extreme micro‐ and macroporosity, foamy nature, and glassy auto‐regolith) on superposed crater formation and retention.
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the cauchy 5 small low volume lunar Shield Volcano evidence for volatile exsolution eruption patterns and type 1 type 2 hybrid irregular mare patch formation
Journal of Geophysical Research, 2020Co-Authors: Le Qiao, Lionel Wilson, J W Head, Zongcheng LingAbstract:The lunar Shield Volcano Cauchy 5, sitting at the low diameter‐height‐volume end of the population, is the only known example containing two different types of Irregular Mare Patches (IMPs) in very close association: (1) the pit crater interior Type 1 IMP composed of bleb‐like mounds surrounded by a hummocky and blocky floor unit and (2) Type 2 IMPs, small, often optically immature pits less than ~5 m deep, located on the generally block‐deficient Shield flanks. A four‐phase lunar magma ascent/eruption model predicts that during a relatively brief eruption, low magma rise rates maximize volatile exsolution in lava filling the pit crater. Bubble‐rich magmas overtop the pit crater and form extremely vesicular flows on the Shield flanks. Exposure of the flanking flows to vacuum produces a fragmental layer of exploded glassy bubble walls. Subsequent second boiling upon cooling of the flanking flow interiors releases additional volatiles which migrate and collect, forming magmatic foams and gas pockets. As magma rise rates slow, trapped gas and magmatic foam build up below the cooling pit crater floor. Magmatic foams are extruded to form Type 1 IMP deposits. Type 2 IMPs on the flanks are interpreted to be due primarily to subsequent impacts causing collapse of the flow surface layer into the extremely vesicle‐ and void‐rich flow interior. Anomalously young pit crater floor/Shield flank crater retention ages compared with surrounding maria ages may be due to effects of Cauchy 5 substrate characteristics (extreme micro‐ and macroporosity, foamy nature, and glassy auto‐regolith) on superposed crater formation and retention.
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geological characterization of the ina Shield Volcano summit pit crater on the moon evidence for extrusion of waning stage lava lake magmatic foams and anomalously young crater retention ages
Journal of Geophysical Research, 2019Co-Authors: Le Qiao, Lionel Wilson, James W. Head, Long Xiao, Zongcheng Ling, Josef DufekAbstract:Ina, a distinctive ~2 × 3 km D-shaped depression, is composed of unusual bulbous-shaped mounds surrounded by optically immature hummocky/blocky floor units. The crisp appearance, optical immaturity, and low number of superposed impact craters combine to strongly suggest a geologically recent formation for Ina, but the specific formation mechanism remains controversial. We reconfirm that Ina is a summit pit crater/vent on a small Shield Volcano ~3.5 billion years old. Following detailed characterization, we interpret the range of Ina characteristics to be consistent with a two-component model of origin during the waning stages of summit pit eruption activities. The Ina pit crater floor is interpreted to be dominated by the products of late-stage, low-rise rate magmatic dike emplacement. Magma in the dike underwent significant shallow degassing and vesicle formation, followed by continued degassing below the solidified and highly microvesicular and macrovesicular lava lake crust, resulting in cracking of the crust and extrusion of gas-rich magmatic foams onto the lava lake crust to form the mounds. These unique substrate characteristics (highly porous aerogel-like foam mounds and floor terrains with large vesicles and void space) exert important effects on subsequent impact crater characteristics and populations, influencing (1) optical maturation processes, (2) regolith development, and (3) landscape evolution by modifying the nature and evolution of superposed impact craters and thus producing anomalously young crater retention ages. Accounting for these effects results in a shift of crater size-frequency distribution model ages from
Magdalena Oryaëlle Chevrel - One of the best experts on this subject based on the ideXlab platform.
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paleomagnetic study of el metate Shield Volcano michoacan mexico confirms its monogenetic nature and young age 1250 ce
Journal of Volcanology and Geothermal Research, 2017Co-Authors: Ahmed Nasser Mahgoub, Harald Böhnel, Claus Siebe, Magdalena Oryaëlle ChevrelAbstract:In a recent study, Chevrel et al. (2016a, b) radiocarbon-dated the oldest lava flow of the voluminous (~ 9.2 km3) El Metate Shield Volcano (Michoacan, Mexico) at cal 1250–1260 CE and proposed that its eruption was monogenetic in origin, with twelve younger lava flows emplaced during a short period of only ~ 35 years, but certainly < 275 years. In order to test this hypothesis, we undertook a detailed paleomagnetic study of five lava flows from El Metate to check the consistency of their paleomagnetic directions. Additionally, a group of representative specimens was treated with the double-heating Thellier experiment using the IZZI protocol for paleointensity determination. Flow mean paleomagnetic directions obtained for four of the flows are indistinguishable, and discordant directions were obtained from the site of the 5th flow measured, probably due to the tilting of the sampled block after remanence acquisition. Mean paleodirections and intensities were used for paleomagnetic dating applying the global paleosecular variation model SHA.DIF.14k. The resulting age range for the eruption is 1150–1290 CE, which overlaps with the range previously determined by the 14C method by Chevrel et al. (2016a). Accepting the 14C age of the oldest flow as the maximum age, the age range would be reduced to 1250–1290 CE, which strongly supports the hypothesis of a monogenetic nature of the El Metate eruption.
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Paleomagnetic study of El Metate Shield Volcano (Michoacán, Mexico) confirms its monogenetic nature and young age (~ 1250 CE)
Journal of Volcanology and Geothermal Research, 2017Co-Authors: Ahmed Nasser Mahgoub, Harald Böhnel, Claus Siebe, Magdalena Oryaëlle ChevrelAbstract:In a recent study, Chevrel et al. (2016a, b) radiocarbon-dated the oldest lava flow of the voluminous (~ 9.2 km3) El Metate Shield Volcano (Michoacan, Mexico) at cal 1250–1260 CE and proposed that its eruption was monogenetic in origin, with twelve younger lava flows emplaced during a short period of only ~ 35 years, but certainly
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The ∼AD 1250 effusive eruption of El Metate Shield Volcano (Michoacán, Mexico): magma source, crustal storage, eruptive dynamics, and lava rheology
Bulletin of Volcanology, 2016Co-Authors: Magdalena Oryaëlle Chevrel, Marie-noëlle Guilbaud, Claus SiebeAbstract:Medium-sized Volcanoes, also known as Mexican Shields due to their andesitic composition and slightly higher slope angles in comparison to Icelandic Shields, occur across the Trans-Mexican Volcanic Belt and represent nearly one third of all volcanic edifices in the Michoacan-Guanajuato Volcanic Field (MGVF). Many questions about their origin and eruptive dynamics remain unanswered. Here, we focus on El Metate, the youngest (∼AD 1250) monogenetic Shield Volcano of the MGVF and the most voluminous (∼9.2 km3 dense rock equivalent) Holocene eruption in Mexico. Its eruptive history was reconstructed through detailed mapping, geochemical analysis (major and trace elements, Sr-Nd-Pb isotopic data), and rheological study of its thick andesitic flows. Early and late flow units have distinct morphologies, chemical and mineralogical compositions, and isotopic signatures which show that these lavas were fed by two separate magma batches that originated from a heterogeneous mantle source and followed distinct differentiation paths during their ascent. Thermobarometry calculations constraining the conditions of crystallization indicate a temporary storage of the last erupted magma batch at a depth of ∼7–10 km. Lava rheology was estimated using petrographic characteristics, geochemical data, and flow dimensions. The magma viscosity increased from 102–103 Pa s prior to eruption through 106–108 Pa s during ascent, to 109–1011 Pa s during lava emplacement. Though magma viscosity was quite high, the eruption was purely effusive. The explosive eruption of such a large magma volume was probably avoided due to efficient open system degassing (outgassing) of the magma as it ascended through the uppermost crust and erupted at the surface.
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the ad 1250 effusive eruption of el metate Shield Volcano michoacan mexico magma source crustal storage eruptive dynamics and lava rheology
Bulletin of Volcanology, 2016Co-Authors: Magdalena Oryaëlle Chevrel, Marie-noëlle Guilbaud, Claus SiebeAbstract:Medium-sized Volcanoes, also known as Mexican Shields due to their andesitic composition and slightly higher slope angles in comparison to Icelandic Shields, occur across the Trans-Mexican Volcanic Belt and represent nearly one third of all volcanic edifices in the Michoacan-Guanajuato Volcanic Field (MGVF). Many questions about their origin and eruptive dynamics remain unanswered. Here, we focus on El Metate, the youngest (∼AD 1250) monogenetic Shield Volcano of the MGVF and the most voluminous (∼9.2 km3 dense rock equivalent) Holocene eruption in Mexico. Its eruptive history was reconstructed through detailed mapping, geochemical analysis (major and trace elements, Sr-Nd-Pb isotopic data), and rheological study of its thick andesitic flows. Early and late flow units have distinct morphologies, chemical and mineralogical compositions, and isotopic signatures which show that these lavas were fed by two separate magma batches that originated from a heterogeneous mantle source and followed distinct differentiation paths during their ascent. Thermobarometry calculations constraining the conditions of crystallization indicate a temporary storage of the last erupted magma batch at a depth of ∼7–10 km. Lava rheology was estimated using petrographic characteristics, geochemical data, and flow dimensions. The magma viscosity increased from 102–103 Pa s prior to eruption through 106–108 Pa s during ascent, to 109–1011 Pa s during lava emplacement. Though magma viscosity was quite high, the eruption was purely effusive. The explosive eruption of such a large magma volume was probably avoided due to efficient open system degassing (outgassing) of the magma as it ascended through the uppermost crust and erupted at the surface.
Claus Siebe - One of the best experts on this subject based on the ideXlab platform.
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paleomagnetic study of el metate Shield Volcano michoacan mexico confirms its monogenetic nature and young age 1250 ce
Journal of Volcanology and Geothermal Research, 2017Co-Authors: Ahmed Nasser Mahgoub, Harald Böhnel, Claus Siebe, Magdalena Oryaëlle ChevrelAbstract:In a recent study, Chevrel et al. (2016a, b) radiocarbon-dated the oldest lava flow of the voluminous (~ 9.2 km3) El Metate Shield Volcano (Michoacan, Mexico) at cal 1250–1260 CE and proposed that its eruption was monogenetic in origin, with twelve younger lava flows emplaced during a short period of only ~ 35 years, but certainly < 275 years. In order to test this hypothesis, we undertook a detailed paleomagnetic study of five lava flows from El Metate to check the consistency of their paleomagnetic directions. Additionally, a group of representative specimens was treated with the double-heating Thellier experiment using the IZZI protocol for paleointensity determination. Flow mean paleomagnetic directions obtained for four of the flows are indistinguishable, and discordant directions were obtained from the site of the 5th flow measured, probably due to the tilting of the sampled block after remanence acquisition. Mean paleodirections and intensities were used for paleomagnetic dating applying the global paleosecular variation model SHA.DIF.14k. The resulting age range for the eruption is 1150–1290 CE, which overlaps with the range previously determined by the 14C method by Chevrel et al. (2016a). Accepting the 14C age of the oldest flow as the maximum age, the age range would be reduced to 1250–1290 CE, which strongly supports the hypothesis of a monogenetic nature of the El Metate eruption.
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Paleomagnetic study of El Metate Shield Volcano (Michoacán, Mexico) confirms its monogenetic nature and young age (~ 1250 CE)
Journal of Volcanology and Geothermal Research, 2017Co-Authors: Ahmed Nasser Mahgoub, Harald Böhnel, Claus Siebe, Magdalena Oryaëlle ChevrelAbstract:In a recent study, Chevrel et al. (2016a, b) radiocarbon-dated the oldest lava flow of the voluminous (~ 9.2 km3) El Metate Shield Volcano (Michoacan, Mexico) at cal 1250–1260 CE and proposed that its eruption was monogenetic in origin, with twelve younger lava flows emplaced during a short period of only ~ 35 years, but certainly
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The ∼AD 1250 effusive eruption of El Metate Shield Volcano (Michoacán, Mexico): magma source, crustal storage, eruptive dynamics, and lava rheology
Bulletin of Volcanology, 2016Co-Authors: Magdalena Oryaëlle Chevrel, Marie-noëlle Guilbaud, Claus SiebeAbstract:Medium-sized Volcanoes, also known as Mexican Shields due to their andesitic composition and slightly higher slope angles in comparison to Icelandic Shields, occur across the Trans-Mexican Volcanic Belt and represent nearly one third of all volcanic edifices in the Michoacan-Guanajuato Volcanic Field (MGVF). Many questions about their origin and eruptive dynamics remain unanswered. Here, we focus on El Metate, the youngest (∼AD 1250) monogenetic Shield Volcano of the MGVF and the most voluminous (∼9.2 km3 dense rock equivalent) Holocene eruption in Mexico. Its eruptive history was reconstructed through detailed mapping, geochemical analysis (major and trace elements, Sr-Nd-Pb isotopic data), and rheological study of its thick andesitic flows. Early and late flow units have distinct morphologies, chemical and mineralogical compositions, and isotopic signatures which show that these lavas were fed by two separate magma batches that originated from a heterogeneous mantle source and followed distinct differentiation paths during their ascent. Thermobarometry calculations constraining the conditions of crystallization indicate a temporary storage of the last erupted magma batch at a depth of ∼7–10 km. Lava rheology was estimated using petrographic characteristics, geochemical data, and flow dimensions. The magma viscosity increased from 102–103 Pa s prior to eruption through 106–108 Pa s during ascent, to 109–1011 Pa s during lava emplacement. Though magma viscosity was quite high, the eruption was purely effusive. The explosive eruption of such a large magma volume was probably avoided due to efficient open system degassing (outgassing) of the magma as it ascended through the uppermost crust and erupted at the surface.
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the ad 1250 effusive eruption of el metate Shield Volcano michoacan mexico magma source crustal storage eruptive dynamics and lava rheology
Bulletin of Volcanology, 2016Co-Authors: Magdalena Oryaëlle Chevrel, Marie-noëlle Guilbaud, Claus SiebeAbstract:Medium-sized Volcanoes, also known as Mexican Shields due to their andesitic composition and slightly higher slope angles in comparison to Icelandic Shields, occur across the Trans-Mexican Volcanic Belt and represent nearly one third of all volcanic edifices in the Michoacan-Guanajuato Volcanic Field (MGVF). Many questions about their origin and eruptive dynamics remain unanswered. Here, we focus on El Metate, the youngest (∼AD 1250) monogenetic Shield Volcano of the MGVF and the most voluminous (∼9.2 km3 dense rock equivalent) Holocene eruption in Mexico. Its eruptive history was reconstructed through detailed mapping, geochemical analysis (major and trace elements, Sr-Nd-Pb isotopic data), and rheological study of its thick andesitic flows. Early and late flow units have distinct morphologies, chemical and mineralogical compositions, and isotopic signatures which show that these lavas were fed by two separate magma batches that originated from a heterogeneous mantle source and followed distinct differentiation paths during their ascent. Thermobarometry calculations constraining the conditions of crystallization indicate a temporary storage of the last erupted magma batch at a depth of ∼7–10 km. Lava rheology was estimated using petrographic characteristics, geochemical data, and flow dimensions. The magma viscosity increased from 102–103 Pa s prior to eruption through 106–108 Pa s during ascent, to 109–1011 Pa s during lava emplacement. Though magma viscosity was quite high, the eruption was purely effusive. The explosive eruption of such a large magma volume was probably avoided due to efficient open system degassing (outgassing) of the magma as it ascended through the uppermost crust and erupted at the surface.