Articles | Volume 37, issue 4
https://doi.org/10.5194/ejm-37-413-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue:
https://doi.org/10.5194/ejm-37-413-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Vesiculation dynamics – Part 2: Decompression-induced H2O vesicle growth, onset, and progression of coalescence
Patricia Louisa Marks
CORRESPONDING AUTHOR
Department of Geosciences, Eberhard Karls University of Tübingen, Tübingen 72074, Germany
Marcus Nowak
Department of Geosciences, Eberhard Karls University of Tübingen, Tübingen 72074, Germany
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Patricia Louisa Marks and Marcus Nowak
Eur. J. Mineral., 37, 385–412, https://doi.org/10.5194/ejm-37-385-2025, https://doi.org/10.5194/ejm-37-385-2025, 2025
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We provide new insights into the release of H2O from the phonolitic melt of the Laacher See volcano. Decompression experiments conducted at superliquidus conditions revealed uniformly dispersed vesicles throughout the samples, with extremely high vesicle numbers regardless of the decompression rate. These findings enhance our understanding of volcanic eruptions and might suggest that rapid volatile release due to off-critical spinodal decomposition increases explosive volcanic activity.
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These results represent the first high-pressure and high-temperature degassing experiments simulating the injection of basaltic melt into a hydrous rhyolitic melt reservoir. Diffusion processes in the contact zone of the melts lead to a depletion of alkalis in the rhyolitic melt interface. The reduced alkali concentration significantly decreases the H2O solubility of the rhyolitic melt and promotes enhanced H2O vesicle formation and further degassing, which can trigger volcanic eruptions.
Patricia Louisa Marks and Marcus Nowak
Eur. J. Mineral., 37, 385–412, https://doi.org/10.5194/ejm-37-385-2025, https://doi.org/10.5194/ejm-37-385-2025, 2025
Short summary
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We provide new insights into the release of H2O from the phonolitic melt of the Laacher See volcano. Decompression experiments conducted at superliquidus conditions revealed uniformly dispersed vesicles throughout the samples, with extremely high vesicle numbers regardless of the decompression rate. These findings enhance our understanding of volcanic eruptions and might suggest that rapid volatile release due to off-critical spinodal decomposition increases explosive volcanic activity.
Patricia Louisa Marks, Anja Allabar, and Marcus Nowak
Eur. J. Mineral., 35, 613–633, https://doi.org/10.5194/ejm-35-613-2023, https://doi.org/10.5194/ejm-35-613-2023, 2023
Short summary
Short summary
These results represent the first high-pressure and high-temperature degassing experiments simulating the injection of basaltic melt into a hydrous rhyolitic melt reservoir. Diffusion processes in the contact zone of the melts lead to a depletion of alkalis in the rhyolitic melt interface. The reduced alkali concentration significantly decreases the H2O solubility of the rhyolitic melt and promotes enhanced H2O vesicle formation and further degassing, which can trigger volcanic eruptions.
Related subject area
Structure and properties of melts
The effect of oxygen fugacity on the evaporation of boron from aluminoborosilicate melt
H2O degassing triggered by alkali depletion in bimodal magma injection processes – a new experimental approach
Stamatis Flemetakis, Christian J. Renggli, Paul Pangritz, Jasper Berndt, and Stephan Klemme
Eur. J. Mineral., 36, 173–181, https://doi.org/10.5194/ejm-36-173-2024, https://doi.org/10.5194/ejm-36-173-2024, 2024
Short summary
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Boron is a common additive in industrial glasses used for a wide variety of applications and in experimental degassing studies regarding exoplanet atmospheres. It is therefore important to constrain the behavior of this component in the melt phase. For this reason we investigated experimentally the evaporation of B2O3 from Ca- and Mg-bearing aluminoborosilicate melts at different temperatures, as a function of time and oxygen fugacity.
Patricia Louisa Marks, Anja Allabar, and Marcus Nowak
Eur. J. Mineral., 35, 613–633, https://doi.org/10.5194/ejm-35-613-2023, https://doi.org/10.5194/ejm-35-613-2023, 2023
Short summary
Short summary
These results represent the first high-pressure and high-temperature degassing experiments simulating the injection of basaltic melt into a hydrous rhyolitic melt reservoir. Diffusion processes in the contact zone of the melts lead to a depletion of alkalis in the rhyolitic melt interface. The reduced alkali concentration significantly decreases the H2O solubility of the rhyolitic melt and promotes enhanced H2O vesicle formation and further degassing, which can trigger volcanic eruptions.
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Short summary
As magma ascends, H2O-supersaturated melt forms fluid vesicles, creating high vesicle number densities (VNDs) and increasing melt porosity, accelerating magma ascent. This study examines how VNDs vary with decompression rate as vesicles begin to coalesce. The shift from decompression-rate-independent to decompression-rate-dependent VND can strongly influence eruption styles, creating permeable channels or forming closed-porosity foams that trap pressurized gas, potentially leading to explosive eruptions.
As magma ascends, H2O-supersaturated melt forms fluid vesicles, creating high vesicle number...
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