Journal ArticleDOI
Volatile Abundances in Basaltic Magmas and Their Degassing Paths Tracked by Melt Inclusions
Nicole Métrich,Paul J. Wallace +1 more
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The abundances of CO2, H2O, S and halogens dissolved in basaltic magmas are strongly variable because their solubilities and ability to be fractionated in the vapor phase depend on several parameters such as pressure, temperature, melt composition and redox state as mentioned in this paper.Abstract:
The abundances of CO2, H2O, S and halogens dissolved in basaltic magmas are strongly variable because their solubilities and ability to be fractionated in the vapor phase depend on several parameters such as pressure, temperature, melt composition and redox state. Experimental and analytical studies show that CO2 is much less soluble in silicate melts compared to H2O (e.g., Javoy and Pineau 1991; Dixon et al. 1995). As much as 90% of the initial CO2 dissolved in basaltic melts may be already degassed at crustal depths, whereas H2O remains dissolved because of its higher solubility such that H2O contents of basaltic magmas at crustal depths may reach a few percents. Most subduction-related basaltic magmas are rich in H2O (up to 6–8 wt%; Sisson and Grove 1993; Roggensack et al. 1997; Newman et al. 2000; Pichavant et al. 2002; Grove et al. 2005) compared to mid-ocean ridge basalts (<1 wt%; Sobolev and Chaussidon 1996; Fischer and Marty 2005; Wallace 2005).
During magma movement towards the surface, exsolution of major volatile constituents (CO2, H2O) causes gas bubble nucleation, growth, and possible coalescence that exert a strong control on the dynamics of magma ascent and eruption (Anderson 1975; Sparks 1978; Tait et al. 1989). Gas bubbles have the ability to move faster than magma (Sparks 1978), particularly in low viscosity basaltic magmas. Bubble accumulation, coalescence and foam collapse give rise to differential transfer of gas slugs and periodic gas bursting (Strombolian activity; Jaupart and Vergniolle 1988, 1989) or periodic lava fountains (Vergniolle and Jaupart 1990; Philips and Wood 2001) depending on magma physical properties and ascent rate. It is also thought that strombolian and lava …read more
Citations
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Journal ArticleDOI
Interactions Between Gas Slug Ascent and Exchange Flow in the Conduit of Persistently Active Volcanoes
Journal ArticleDOI
Redox behavior of degassing magmas: critical review and comparison of glass-based oxybarometers with application to Etna volcano
TL;DR: In this paper , the authors show that any assessment of redox behavior that does not account for the melt reactivity, driven by melt polymerization and the so-called oxygen electrode in association with iron or sulfur redox couples, may fail in determining the actual contribution of the composition to the observed variations of iron and sulfur oxidation states, resulting in potentially biased fO 2 estimates.
Journal ArticleDOI
Global Rates of Subaerial Volcanism on Earth
TL;DR: In this paper , the authors describe and validate a model that reproduces global volcanism to high statistical significance, and use the model to compute the expected rates of global terrestrial volcanism over time windows from 1 to 100,000 years and validate it by comparing with observations back to a few million years.
Degassing vs. eruptive styles at Mt. Etna volcano (Sicily, Italy): Volatile stocking, gas fluxing, and the shift from low-energy to highly-explosive basaltic eruptions
Roberto Moretti,Nicole Métrich,Valeria Di Renzo,Alessandro Aiuppa,Patrick Allard,Ilenia Arienzo +5 more
TL;DR: In this paper, the authors show that for the same initial volatile content, different eruptive styles reflect variable degassing paths throughout the composite Etnean plumbing system, and the combined influence of crystallization, deep degassing and CO2 gas fluxing can explain the evolution of H2O, CO2, S and Cl in products from a spectrum of activity.
DissertationDOI
Investigations into the degassing and eruption mechanisms of Nyamuragira volcano, Democratic Republic of the Congo (Africa)
TL;DR: In this paper, the authors used a Landsat/Hyperion/ALI dataset and automated classification methods to map lava flows at Nyamuragira volcano (1967-2011) in the Democratic Republic of the Congo.
References
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Geochimica et Cosmochimica Acta. "The carbon isotope biogeochemistry of acetate from methanogenic marine sediment." by N. E. Blair and W. D. Carter Jr. published in 56, 1247-1258
Journal ArticleDOI
Tectonic Implications of the Composition of Volcanic Arc Magmas
Julian A. Pearce,David W. Peate +1 more
TL;DR: In this paper, the authors summarize knowledge of the behavior of elements in the subduction system and highlight the physical and chemical processes that have been invoked as being important in controlling the composition of volcanic arc magmas.
Journal ArticleDOI
Major and trace element composition of the depleted MORB mantle (DMM)
R. Workman,Stanley R. Hart +1 more
TL;DR: Asimow et al. as mentioned in this paper derived an estimate for the chemical composition of the depleted MORB mantle (DMM), the source reservoir to mid-ocean ridge basalts (MORBs), which represents at least 30% the mass of the whole silicate Earth.
Journal ArticleDOI
Geochim. cosmochim. acta: Rubin A.E. and Wasson J. T. (1987) Chondrules, matrix and coarsegrained chondrule rims in the Allende meteorite: Origin, interrelationships and possible precursor components 51, 1923–1937
Alan E. Rubin,John T. Wasson +1 more
Journal ArticleDOI
Trace element signature of subduction-zone fluids, melts and supercritical liquids at 120–180 km depth
TL;DR: Measurements of the composition of fluids and melts equilibrated with a basaltic eclogite at pressures equivalent to depths in the Earth and temperatures of 700–1,200 °C constrain the recycling rates of key elements in subduction-zone arc volcanism.
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