A simple model of Rn-222 accumulation leading to Pb-210 excesses in volcanic rocks
While most rocks from active volcanoes display ((210)pb/Ra-226) activity ratios lower than or close to the equilibrium value of 1, several other have ratios much higher than 1. Transfer of Rn-222 by magmatic volatiles has often been advocated to explain both Pb-210 deficits and excesses. We develop...
Published in: | Earth and Planetary Science Letters |
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Format: | Article in Journal/Newspaper |
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Online Access: | https://doi.org/10.1016/j.epsl.2010.02.048 https://hal.archives-ouvertes.fr/hal-00496398 |
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fttriple:oai:gotriple.eu:10670/1.4n731u 2023-05-15T16:51:09+02:00 A simple model of Rn-222 accumulation leading to Pb-210 excesses in volcanic rocks Condomines, Michel Sigmarsson, Olgeir Gauthier, P. J. Géosciences Montpellier Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) Laboratoire Magmas et Volcans (LMV) Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet Saint-Étienne (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) 2010-01-01 https://doi.org/10.1016/j.epsl.2010.02.048 https://hal.archives-ouvertes.fr/hal-00496398 en eng HAL CCSD Elsevier hal-00496398 doi:10.1016/j.epsl.2010.02.048 10670/1.4n731u https://hal.archives-ouvertes.fr/hal-00496398 undefined Hyper Article en Ligne - Sciences de l'Homme et de la Société ISSN: 0012-821X Earth and Planetary Science Letters Earth and Planetary Science Letters, Elsevier, 2010, 293 (3-4), pp.331-338. ⟨10.1016/j.epsl.2010.02.048⟩ Radon degassing and accumulation in magmas (210)pb-Ra-226 disequilibria Pb-210 excesses in volcanic rocks Santorini volcano Surtsey Island geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2010 fttriple https://doi.org/10.1016/j.epsl.2010.02.048 2023-01-22T18:42:35Z While most rocks from active volcanoes display ((210)pb/Ra-226) activity ratios lower than or close to the equilibrium value of 1, several other have ratios much higher than 1. Transfer of Rn-222 by magmatic volatiles has often been advocated to explain both Pb-210 deficits and excesses. We develop here a model to account for Pb-210 excesses through Rn-222 accumulation. We show that large Pb-210 excesses can be readily obtained, even for moderate ratios of degassing magma over accumulating magma, in a closed-system model where the Rn-222 atoms produced by decay of Ra-226 in the degassing magma are continuously extracted by a gas phase. For a given duration of volatile transfer, relative Pb-210 excesses are expected to be much larger than Pb-210 deficits. This model is applied to samples from Santorini (Aegean arc) and Surtsey (Iceland) both of which show high ((210)pb/Ra-226) ratios of 6.7 and 2.3 respectively at the time of eruption. The agreement with field data suggests that Rn-222 accumulation leading to Pb-210 excesses might be a rather common process in zoned magma chambers as well as in individual lava flows, and that it can be described by a closed-system model. Article in Journal/Newspaper Iceland Surtsey Unknown Surtsey ENVELOPE(-20.608,-20.608,63.301,63.301) Earth and Planetary Science Letters 293 3-4 331 338 |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
English |
topic |
Radon degassing and accumulation in magmas (210)pb-Ra-226 disequilibria Pb-210 excesses in volcanic rocks Santorini volcano Surtsey Island geo envir |
spellingShingle |
Radon degassing and accumulation in magmas (210)pb-Ra-226 disequilibria Pb-210 excesses in volcanic rocks Santorini volcano Surtsey Island geo envir Condomines, Michel Sigmarsson, Olgeir Gauthier, P. J. A simple model of Rn-222 accumulation leading to Pb-210 excesses in volcanic rocks |
topic_facet |
Radon degassing and accumulation in magmas (210)pb-Ra-226 disequilibria Pb-210 excesses in volcanic rocks Santorini volcano Surtsey Island geo envir |
description |
While most rocks from active volcanoes display ((210)pb/Ra-226) activity ratios lower than or close to the equilibrium value of 1, several other have ratios much higher than 1. Transfer of Rn-222 by magmatic volatiles has often been advocated to explain both Pb-210 deficits and excesses. We develop here a model to account for Pb-210 excesses through Rn-222 accumulation. We show that large Pb-210 excesses can be readily obtained, even for moderate ratios of degassing magma over accumulating magma, in a closed-system model where the Rn-222 atoms produced by decay of Ra-226 in the degassing magma are continuously extracted by a gas phase. For a given duration of volatile transfer, relative Pb-210 excesses are expected to be much larger than Pb-210 deficits. This model is applied to samples from Santorini (Aegean arc) and Surtsey (Iceland) both of which show high ((210)pb/Ra-226) ratios of 6.7 and 2.3 respectively at the time of eruption. The agreement with field data suggests that Rn-222 accumulation leading to Pb-210 excesses might be a rather common process in zoned magma chambers as well as in individual lava flows, and that it can be described by a closed-system model. |
author2 |
Géosciences Montpellier Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) Laboratoire Magmas et Volcans (LMV) Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet Saint-Étienne (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Condomines, Michel Sigmarsson, Olgeir Gauthier, P. J. |
author_facet |
Condomines, Michel Sigmarsson, Olgeir Gauthier, P. J. |
author_sort |
Condomines, Michel |
title |
A simple model of Rn-222 accumulation leading to Pb-210 excesses in volcanic rocks |
title_short |
A simple model of Rn-222 accumulation leading to Pb-210 excesses in volcanic rocks |
title_full |
A simple model of Rn-222 accumulation leading to Pb-210 excesses in volcanic rocks |
title_fullStr |
A simple model of Rn-222 accumulation leading to Pb-210 excesses in volcanic rocks |
title_full_unstemmed |
A simple model of Rn-222 accumulation leading to Pb-210 excesses in volcanic rocks |
title_sort |
simple model of rn-222 accumulation leading to pb-210 excesses in volcanic rocks |
publisher |
HAL CCSD |
publishDate |
2010 |
url |
https://doi.org/10.1016/j.epsl.2010.02.048 https://hal.archives-ouvertes.fr/hal-00496398 |
long_lat |
ENVELOPE(-20.608,-20.608,63.301,63.301) |
geographic |
Surtsey |
geographic_facet |
Surtsey |
genre |
Iceland Surtsey |
genre_facet |
Iceland Surtsey |
op_source |
Hyper Article en Ligne - Sciences de l'Homme et de la Société ISSN: 0012-821X Earth and Planetary Science Letters Earth and Planetary Science Letters, Elsevier, 2010, 293 (3-4), pp.331-338. ⟨10.1016/j.epsl.2010.02.048⟩ |
op_relation |
hal-00496398 doi:10.1016/j.epsl.2010.02.048 10670/1.4n731u https://hal.archives-ouvertes.fr/hal-00496398 |
op_rights |
undefined |
op_doi |
https://doi.org/10.1016/j.epsl.2010.02.048 |
container_title |
Earth and Planetary Science Letters |
container_volume |
293 |
container_issue |
3-4 |
container_start_page |
331 |
op_container_end_page |
338 |
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1766041256731869184 |