The effect of pores (fluid-filled vs. drained) on magma rheology
The presence of pore space strongly affects the rheological behavior of magma and thus influences all volcanic processes (pre-, syn- and post- eruptive). The effects of porosity on magma rheology are, however, unresolved and subject to debate. Here, we present new high-temperature experiments design...
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ftunivroma3iris:oai:iris.uniroma3.it:11590/385629 2024-05-19T07:42:54+00:00 The effect of pores (fluid-filled vs. drained) on magma rheology Stefania Sicola Alessandro Vona Amy G. Ryan James K. Russell Claudia Romano Sicola, Stefania Vona, Alessandro Ryan, Amy G. Russell, James K. Romano, Claudia 2021 https://hdl.handle.net/11590/385629 https://doi.org/10.1016/j.chemgeo.2021.120147 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000637385500007 volume:569 firstpage:1 lastpage:13 numberofpages:13 journal:CHEMICAL GEOLOGY https://hdl.handle.net/11590/385629 doi:10.1016/j.chemgeo.2021.120147 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85102404684 Magma viscosity Rhyolite Porous volcanic material Vesicularity Fluid-filled bubbles Drained pores info:eu-repo/semantics/article 2021 ftunivroma3iris https://doi.org/10.1016/j.chemgeo.2021.120147 2024-04-23T02:23:41Z The presence of pore space strongly affects the rheological behavior of magma and thus influences all volcanic processes (pre-, syn- and post- eruptive). The effects of porosity on magma rheology are, however, unresolved and subject to debate. Here, we present new high-temperature experiments designed to constrain the rheological properties of variably porous melts (0.09–0.66 fractional porosity) deforming at high temperature (750–800 ◦C) and low strain rates (10 4 — 10 7 s 1). The starting materials are cylindrical cores of natural vesicle- and crystalfree rhyolitic obsidian from Krafla (Iceland) initially containing 0.114 wt% of dissolved H2O. Our experiments comprise two steps. First, cores are heated above the glass transition temperature (700 ◦C) to 900–1050 ◦C; second, the cores are deformed at lower temperatures (750 or 800 ◦C) under a constant low load (1.5 N). We have employed two different strategies for the second step: i) samples are deformed in situ directly after foaming (single-stage, SS); or ii) samples are quenched then reheated and deformed at 750 ◦C after 15 days repose at room conditions (double-stage, DS). Our experiments provide data that inform on the effects of porosity on the viscosity of natural rhyolitic deposits (e.g., ignimbrites, lavas, domes). Discordant results between SS and DS experiments (~0.6 log10 Pa s for 0.5 fractional porosity) suggest that the rheology of porous volcanic materials depends on whether pore spaces are isolated, fluid-filled bubbles (e.g., magmas in the conduit) or are interconnected, drained voids (e.g., domes, lavas, pyroclastic deposits). Article in Journal/Newspaper Iceland Anagrafe della Ricerca d'Ateneo (Universitá degli studi Roma Tre) Chemical Geology 569 120147 |
institution |
Open Polar |
collection |
Anagrafe della Ricerca d'Ateneo (Universitá degli studi Roma Tre) |
op_collection_id |
ftunivroma3iris |
language |
English |
topic |
Magma viscosity Rhyolite Porous volcanic material Vesicularity Fluid-filled bubbles Drained pores |
spellingShingle |
Magma viscosity Rhyolite Porous volcanic material Vesicularity Fluid-filled bubbles Drained pores Stefania Sicola Alessandro Vona Amy G. Ryan James K. Russell Claudia Romano The effect of pores (fluid-filled vs. drained) on magma rheology |
topic_facet |
Magma viscosity Rhyolite Porous volcanic material Vesicularity Fluid-filled bubbles Drained pores |
description |
The presence of pore space strongly affects the rheological behavior of magma and thus influences all volcanic processes (pre-, syn- and post- eruptive). The effects of porosity on magma rheology are, however, unresolved and subject to debate. Here, we present new high-temperature experiments designed to constrain the rheological properties of variably porous melts (0.09–0.66 fractional porosity) deforming at high temperature (750–800 ◦C) and low strain rates (10 4 — 10 7 s 1). The starting materials are cylindrical cores of natural vesicle- and crystalfree rhyolitic obsidian from Krafla (Iceland) initially containing 0.114 wt% of dissolved H2O. Our experiments comprise two steps. First, cores are heated above the glass transition temperature (700 ◦C) to 900–1050 ◦C; second, the cores are deformed at lower temperatures (750 or 800 ◦C) under a constant low load (1.5 N). We have employed two different strategies for the second step: i) samples are deformed in situ directly after foaming (single-stage, SS); or ii) samples are quenched then reheated and deformed at 750 ◦C after 15 days repose at room conditions (double-stage, DS). Our experiments provide data that inform on the effects of porosity on the viscosity of natural rhyolitic deposits (e.g., ignimbrites, lavas, domes). Discordant results between SS and DS experiments (~0.6 log10 Pa s for 0.5 fractional porosity) suggest that the rheology of porous volcanic materials depends on whether pore spaces are isolated, fluid-filled bubbles (e.g., magmas in the conduit) or are interconnected, drained voids (e.g., domes, lavas, pyroclastic deposits). |
author2 |
Sicola, Stefania Vona, Alessandro Ryan, Amy G. Russell, James K. Romano, Claudia |
format |
Article in Journal/Newspaper |
author |
Stefania Sicola Alessandro Vona Amy G. Ryan James K. Russell Claudia Romano |
author_facet |
Stefania Sicola Alessandro Vona Amy G. Ryan James K. Russell Claudia Romano |
author_sort |
Stefania Sicola |
title |
The effect of pores (fluid-filled vs. drained) on magma rheology |
title_short |
The effect of pores (fluid-filled vs. drained) on magma rheology |
title_full |
The effect of pores (fluid-filled vs. drained) on magma rheology |
title_fullStr |
The effect of pores (fluid-filled vs. drained) on magma rheology |
title_full_unstemmed |
The effect of pores (fluid-filled vs. drained) on magma rheology |
title_sort |
effect of pores (fluid-filled vs. drained) on magma rheology |
publishDate |
2021 |
url |
https://hdl.handle.net/11590/385629 https://doi.org/10.1016/j.chemgeo.2021.120147 |
genre |
Iceland |
genre_facet |
Iceland |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000637385500007 volume:569 firstpage:1 lastpage:13 numberofpages:13 journal:CHEMICAL GEOLOGY https://hdl.handle.net/11590/385629 doi:10.1016/j.chemgeo.2021.120147 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85102404684 |
op_doi |
https://doi.org/10.1016/j.chemgeo.2021.120147 |
container_title |
Chemical Geology |
container_volume |
569 |
container_start_page |
120147 |
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