C–O–H–S fluids and granitic magma: how S partitions and modifies CO2 concentrations of fluid-saturated felsic melt at 200 MPa

Webster, James D.; Goldoff, B. A.; Shimizu, Nobumichi

doi:10.1007/s00410-011-0628-1

Cited by 29 publications

(3 citation statements)

References 42 publications

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“…In contrast, in Mauna Kea magma, an H 2 O‐poor (<1 wt.%) oceanic island basalt with low initial S 6+ /ΣS (∼0.1), almost no sulfur degasses until shallow pressures (<45 MPa, dashed curve in Figure 9a). The contrasting modeled sulfur degassing paths challenge current degassing models (e.g., SolEx, MP04) that predict sulfur loss only at pressures lower than 150 MPa (e.g., J. G. Moore & Fabbi, 1971; J. G. Moore & Schilling, 1973; Webster et al., 2011). Despite all of the experiments used for calibrating Sulfur_X that demonstrates the preference of sulfur for the vapor phase to varying extents from 70 to 500 MPa, the SolEx and MP04 models are still widely applied to interpret MI data (e.g., Ferguson et al., 2016; Robidoux et al., 2018) and high‐ T volcanic gas data (e.g., Aiuppa et al., 2017; de Moor et al., 2016; Robidoux et al., 2017).…”

Section: Discussionmentioning

confidence: 88%

Sulfur_X: A Model of Sulfur Degassing During Magma Ascent

Ding

Plank

Wallace

et al. 2023

Geochem Geophys Geosyst

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Degassing of arc magmas is the dominant mechanism through which volatiles (H 2 O, C, S, and halogens) stored inside the Earth enter the surface environment, with significant effects on climate and redox evolution. Geochemical quantification of gas emissions is also becoming increasingly critical for understanding how volcanoes prepare to erupt. Given that sulfur can be present in both oxidized and reduced form in the melt and vapor, degassing of sulfur during magma ascent has been invoked as one of the mechanisms that drives redox changes in basaltic magmas (Brounce et al., 2017;Longpré et al., 2017;Moussallam et al., 2016). Currently, three approaches, including volcanic gas observations, microanalysis of volatiles in degassing magmas, and thermodynamic modeling, are commonly used to investigate volcanic degassing. In particular, models of volcanic degassing can link the geochemical records of volcanic gases and melts (e.g., Werner et al., 2020). Thus, the three approaches studied in concert provide the most powerful approach to understanding volcanic degassing.Melt inclusions (MIs) captured inside crystals at varying depths have the potential to record the magma degassing path as a function of pressure. Modeling equilibrium degassing of CO 2 and S is commonly employed to understand the CO 2 /SO 2 ratio in volcanic gases, CO 2 and S contents in mineral-hosted MIs, and degassing depths (Burton et al., 2007;Scaillet & Pichavant, 2003). For example, a sudden increase in the CO 2 /SO 2 ratio

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Section: Discussionmentioning

confidence: 88%

Sulfur_X: A Model of Sulfur Degassing During Magma Ascent

Ding

Plank

Wallace

et al. 2023

Geochem Geophys Geosyst

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“…Finally another experiment VILLA_P2 was run using a powdered mixture of natural basaltic andesite from Villarrica volcano (same starting material as described in Moussallam et al, 2023) to which deionized water, elemental sulfur and oxalic acid dihydrate were added such that the initial concentrations of CO2 and S would be above saturation level (based on previous experiments on similar composition) at the conditions of the experiment. The charge was run in an internally heated pressure vessel at the American Museum of Natural History and equilibrated at 300 MPa, 1150˚C for 2h at the intrinsic fO2 of the vessel (~NNO+2; Webster et al, 2011). Both INSOL_MX1_BA4 and VILLA_P2 are not part of the reference material suite that we present here as they were not synthesised in sufficient quantities but were used for calibration purposes during some of the SIMS sessions discussed below.…”

Section: Experimental Methodsmentioning

confidence: 99%

ND70 series basaltic glass reference materials for volatile element (H2O, CO2, S, Cl, F) analysis and the C ionisation efficiency suppression effect of water in silicate glasses in SIMS analysis.

Moussallam,

Towbin,

Plank

et al. 2024

Preprint

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We present a new set of reference material, the ND70-series, for in situ analysis of volatile elements (H2O, CO2, S, Cl, F) in silicate glass of basaltic composition. Samples have been synthesised in piston cylinders at pressures of 1 to 1.5 GPa at volatile-undersaturated conditions. They span concentrations from 0 to 6 wt.% H2O, from 0 to 1.6 wt.% CO2 and from 0 to 1 wt.% S, Cl and F. The samples have been characterised by Elastic Recoil Detection Analysis (ERDA) for H2O, by Nuclear Reaction Analysis (NRA) for CO2, by Elemental Analyser (EA) for CO2, by Fourier Transform Infrared Spectroscopy (FTIR) for H2O and CO2, by Secondary Ion Mass Spectrometry (SIMS) for H2O, CO2, S, Cl and F, and by Electron Microprobe (EMP) for CO2, S, Cl, and major elements. Comparison between expected and measured volatile amounts across techniques and institutions is excellent. It was found however that SIMS analyses of CO2 concentrations using either Cs+ or O– primary beams are strongly affected by the glass H2O content. Reference materials are being distributed at Ion probe facilities in the US, Europe and Japan. Remaining reference materials will be deposited at the Smithsonian National Museum of Natural History where they will be freely available on loan to any researcher.

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“…There have also been a few studies with an extra volatile component such as He, Cl, or S in addition to CO 2 and H 2 O (Paonita et al 2000;Botcharnikov et al 2007;Webster et al 2011), but these studies typically emphasize the effect of CO 2 on the solubility of the extra volatile component rather than CO 2 solubility itself.…”

Section: Fluid Composition Analysismentioning

confidence: 99%

Carbon in Silicate Melts

Keppler

2013

Reviews in Mineralogy and Geochemistry

101

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not only introduce an additional, unwanted component, but it may also reduce CO 2 to other carbon species. Reduction may also be enhanced, perhaps through catalytic effects, by the capsule material, such as pure Pt. In order to retain carbon in the +4 oxidation state in such experiments, the oxygen fugacity therefore has to be kept high and diffusion of hydrogen into the capsule has to be suppressed as far as possible. In studies of Fe-bearing melts, the problem of iron loss to Pt can be alleviated by pre-saturating Pt capsules with Fe. Under high temperature and pressure, small amounts of melt components, such as alkali, may dissolve into the fluid phase. Despite all these experimental complexities, it is possible to produce a silicate melt of designated composition coexisting with a fluid with CO 2 mole fraction X CO 2 > 90%, which can be treated approximately as a system with a single volatile component CO 2. Analytical techniques. The CO 2 concentration in the glass quenched from a CO 2-saturated run gives the CO 2 solubility of a melt at a specific pressure and temperature, if the concentration remained unchanged during quenching. Under equivalent conditions, CO 2 solubility is one to two orders of magnitude lower than the solubility of H 2 O. The low solubility of CO 2 and the limitation of then available analytical techniques (e.g., weight loss) caused early experimental studies to center on GPa level pressures. β-track autoradiography was once used frequently in carbon analysis (e.g., Mysen et al. 1975, 1976), but later it was found to yield inaccurate carbon concentration (Tingle and Aines 1988; Blank and Brooker 1994). FTIR has become by far the most frequently adopted analytical technique (Table 1) because it non-destructively probes both CO 2 and H 2 O, measures concentrations down to ppm level with high accuracy, and delivers information about carbon speciation. The molar absorptivities of FTIR bands (2350 cm −1 for molecular CO 2 and the doublets within 1350-1650 cm −1 for CO 3 2−) for each specific melt composition need to be pre-calibrated by absolute methods (such as manometry or bulk carbon analyzers). Different authors may report CO 2 solubility based on different molar absorptivities, which is a major source of inconsistency between different data sets. Combined with stepped heating, it is plausible to separate adsorbed carbon, CO 2 from vesicles in the glass, and the actual dissolved carbon (e.g., Jendrzejewski et al. 1997). In addition to FTIR and the bulk analytical methods, SIMS and NMR (nuclear magnetic resonance) have also been occasionally used for carbon analysis (

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C–O–H–S fluids and granitic magma: how S partitions and modifies CO2 concentrations of fluid-saturated felsic melt at 200 MPa

Cited by 29 publications

References 42 publications

Sulfur_X: A Model of Sulfur Degassing During Magma Ascent

Sulfur_X: A Model of Sulfur Degassing During Magma Ascent

ND70 series basaltic glass reference materials for volatile element (H2O, CO2, S, Cl, F) analysis and the C ionisation efficiency suppression effect of water in silicate glasses in SIMS analysis.

Carbon in Silicate Melts

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