Felix W. von Aulock
Outgassing from Open and Closed Magma Foams
von Aulock, Felix W.; Kennedy, Ben M.; Maksimenko, Anton; Wadsworth, Fabian B.; Lavallée, Yan
Authors
Ben M. Kennedy
Anton Maksimenko
Dr Fabian Wadsworth fabian.b.wadsworth@durham.ac.uk
Associate Professor
Yan Lavallée
Abstract
During magma ascent, bubbles nucleate, grow, coalesce, and form a variably permeable porous network. The reorganization, failing and sealing of bubble walls may contribute to the opening and closing of the volcanic system. In this contribution we cause obsidian to nucleate and grow bubbles to high gas volume fraction at atmospheric pressure by heating samples to 950°C for different times and we image the growth through a furnace. Following the experiment, we imaged the internal pore structure of selected samples in 3D and then dissected for analysis of textures and dissolved water content remnant in the glass. We demonstrate that in these high viscosity systems, during foaming and subsequent foam-maturation, bubbles near a free surface resorb via diffusion to produce an impermeable skin of melt around a foam. The skin thickens non-linearly through time. The water concentrations at the outer and inner skin margins reflect the solubility of water in the melt at the partial pressure of water in atmospheric and water-rich bubble conditions, respectively. In this regime, mass transfer of water out of the system is diffusion limited and the sample shrinks slowly. In a second set of experiments in which we polished off the skin of the foamed samples and placed them back in the furnace to allow open system outgassing, we observe rapid sample contraction and collapse of the connected pore network under surface tension as the system efficiently outgasses. In this regime, mass transfer of water is permeability limited. We conclude that diffusion-driven skin formation can efficiently seal connectivity in foams. When rupture of melt film around gas bubbles (i.e., skin removal) occurs, then rapid outgassing and consequent foam collapse modulate gas pressurization in the vesiculated magma. The mechanisms described here are relevant to the evolution of pore network heterogeneity in permeable magmas.
Citation
von Aulock, F. W., Kennedy, B. M., Maksimenko, A., Wadsworth, F. B., & Lavallée, Y. (2017). Outgassing from Open and Closed Magma Foams. Frontiers in Earth Science, 5, Article 46. https://doi.org/10.3389/feart.2017.00046
Journal Article Type | Article |
---|---|
Acceptance Date | May 26, 2017 |
Online Publication Date | Jun 19, 2017 |
Publication Date | Jun 19, 2017 |
Deposit Date | Mar 20, 2018 |
Publicly Available Date | Apr 18, 2018 |
Journal | Frontiers in Earth Science |
Publisher | Frontiers Media |
Peer Reviewed | Peer Reviewed |
Volume | 5 |
Article Number | 46 |
DOI | https://doi.org/10.3389/feart.2017.00046 |
Files
Published Journal Article
(1.6 Mb)
PDF
Publisher Licence URL
http://creativecommons.org/licenses/by/4.0/
Copyright Statement
Copyright © 2017 von Aulock, Kennedy, Maksimenko, Wadsworth and Lavallée. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
You might also like
Melt diffusion-moderated crystal growth and its effect on euhedral crystal shapes
(2023)
Journal Article
Possible magmatic CO2 influence on the Laacher See eruption date
(2023)
Journal Article
Downloadable Citations
About Durham Research Online (DRO)
Administrator e-mail: dro.admin@durham.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search