scholarly journals Linking Magma Storage and Ascent to Eruption Volume and Composition at an Arc Caldera

2020 ◽  
Vol 47 (14) ◽  
Author(s):  
David Miller ◽  
Ninfa Bennington ◽  
Matthew Haney ◽  
Paul Bedrosian ◽  
Kerry Key ◽  
...  
Keyword(s):  
Magma Storage ◽  
Eruption Volume

scholarly journals Evidence of active magmatic rifting at the Ma’Alalta volcanic field (Afar, Ethiopia)

2021 ◽  
Vol 83 (6) ◽  
Author(s):  
Gianmaria Tortelli ◽  
Anna Gioncada ◽  
Carolina Pagli ◽  
Mauro Rosi ◽  
Laura De Dosso ◽  
...  
Keyword(s):  
Seismic Data ◽  
Volcanic Field ◽  
Lava Flows ◽  
Magmatic Activity ◽  
Magma Storage ◽  
Plumbing System ◽  
Mafic Lava ◽  
Cinder Cones ◽  
Mafic Rocks ◽  
Seismic Networks

AbstractDuring continental rifting, strain and magmatism are believed to localize to narrow magmatic segments, while the rift margin is progressively abandoned. We integrate volcanological, geochemical, petrological and seismic data from the Ma’Alalta volcanic field (MVF) near the western margin of Afar, to show that the MVF is an active magmatic segment. Magmatism in MVF initiated with lava flows and large-volume, caldera-forming ignimbrites from a central edifice. However, the most recent magmatic activity shifted towards mafic lava fields, cinder cones and obsidian-rich silicic domes erupted from vents aligned NNW-SSE, defining a ~ 35-km-long magmatic segment. Along the same area, a NNW-SSE alignment of earthquakes was recorded by two local seismic networks (2005–2009 and 2011–2013). The geochemistry of the mafic rocks is similar to those of nearby axial volcanoes. Inferred magma storage depth from mineral geobarometry shows that a shallow, silicic chamber existed at ~ 5-km depth below the stratovolcano, while a stacked plumbing system with at least three magma storage levels between 9 and 24 km depth fed the recent basalts. We interpret the wide set of observations from the MVF as evidence that the area is an active magmatic segment, showing that localised axial extension can be heavily offset towards the rift margin.

Deciphering magma storage and ascent processes of Taranaki, New Zealand, from the complexity of amphibole breakdown textures

Lithos ◽  
2021 ◽  
pp. 106264
Author(s):  
Nessa G. D'Mello ◽  
Georg F. Zellmer ◽  
Marianne Negrini ◽  
Gabor Kereszturi ◽  
Jonathan Procter ◽  
...  
Keyword(s):  
New Zealand ◽  
Magma Storage

Parental Melts and Magma Storage of a Large-volume Dacite Eruption at Vetrovoy Isthmus (Iturup Island, Southern Kuril Islands): Insights into the Genesis of Subduction-zone Dacites

2019 ◽  
Vol 60 (7) ◽  
pp. 1349-1370
Author(s):  
S Z Smirnov ◽  
A V Rybin ◽  
N N Kruk ◽  
T Yu Timina ◽  
E N Sokolova ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Large Volume ◽  
Peritectic Reaction ◽  
Fluid Pressure ◽  
Kuril Islands ◽  
Strong Increase ◽  
Magma Storage ◽  
Ti Oxides ◽  
Partial Melts ◽  
Parental Melts

Abstract Detailed mineralogical and melt and fluid inclusion constraints on magma storage, and the evolution of melts, are presented for the large-volume caldera eruption on the Vetrovoy Isthmus on Itutrup Island (Kuril Islands, Russia). The shallow magma reservoir beneath the Vetrovoy Isthmus is composed of a mush of plagio-rhyolitic melt, phenocrysts and the products of peritectic reaction(s). The melt appears to have formed as a result of partial melting of previously erupted rocks, which probably had andesitic to basaltic compositions and were metamorphosed into amphibole-bearing assemblages. The breakdown of amphibole in the partially melted precursor rocks led to the formation of early Mg-rich clino- and orthopyroxene, along with plagioclase and Fe–Ti oxides, and the release of aqueous fluids. Variations in fluid pressure are recorded by a strong increase of An contents in plagioclase. Crystallization took place at around 850°C with pressure ranging from 0·9 to 3 kbar. This study demonstrates that dacitic magmas erupted during the course of a 20 kyr voluminous eruption were the result of mixing between plagio-rhyolitic partial melts and the breakdown reaction minerals (i.e. pyroxenes, plagioclase and Fe–Ti oxides). Plagioclase and quartz were the last minerals to crystallize from these melts prior to eruption.

scholarly journals The Crustal Magma Storage System of Volcán Quizapu, Chile, and the Effects of Magma Mixing on Magma Diversity

2012 ◽  
Vol 53 (4) ◽  
pp. 801-840 ◽  
Author(s):  
Philipp Ruprecht ◽  
George W. Bergantz ◽  
Kari M. Cooper ◽  
Wes Hildreth
Keyword(s):  
Magma Mixing ◽  
Storage System ◽  
Magma Storage ◽  
Crustal Magma

scholarly journals Dynamic Magma Storage at Near‐Ridge Hot Spots: Evidence From New Galápagos Gravity Data

2020 ◽  
Vol 21 (3) ◽  
Author(s):  
Z. Cleary ◽  
D. M. Schwartz ◽  
E. Mittelstaedt ◽  
K. Harpp
Keyword(s):  
Hot Spots ◽  
Gravity Data ◽  
Magma Storage
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