An experimental study of the effect of water and chlorine on plagioclase nucleation and growth in mafic magmas: application to mafic pegmatites
In this study, the effects of H2O and Cl on the grain size and nucleation delay of plagioclase in basaltic magma were investigated using dynamic and equilibrium experiments at 1150 ∘C, 300 MPa, and oxygen fugacity between FMQ − 1.65 and FMQ + 0.05 (fayalite–magnetite–quartz). Each experiment consist...
Published in: | European Journal of Mineralogy |
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Language: | English |
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Copernicus Publications
2023
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00070437 2024-01-14T10:09:24+01:00 An experimental study of the effect of water and chlorine on plagioclase nucleation and growth in mafic magmas: application to mafic pegmatites Heckmann, Paul Iacono-Marziano, Giada Strmić Palinkaš, Sabina 2023-12 electronic https://doi.org/10.5194/ejm-35-1111-2023 https://noa.gwlb.de/receive/cop_mods_00070437 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00068786/ejm-35-1111-2023.pdf https://ejm.copernicus.org/articles/35/1111/2023/ejm-35-1111-2023.pdf eng eng Copernicus Publications European Journal of Mineralogy -- Eur.j.mineral -- http://www.bibliothek.uni-regensburg.de/ezeit/?2039451 -- http://eurjmin.geoscienceworld.org/ -- http://www.schweizerbart.de/j/ejm/index.html -- https://www.ingentaconnect.com/content/schweiz/ejm -- 1617-4011 https://doi.org/10.5194/ejm-35-1111-2023 https://noa.gwlb.de/receive/cop_mods_00070437 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00068786/ejm-35-1111-2023.pdf https://ejm.copernicus.org/articles/35/1111/2023/ejm-35-1111-2023.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2023 ftnonlinearchiv https://doi.org/10.5194/ejm-35-1111-2023 2023-12-18T00:22:46Z In this study, the effects of H2O and Cl on the grain size and nucleation delay of plagioclase in basaltic magma were investigated using dynamic and equilibrium experiments at 1150 ∘C, 300 MPa, and oxygen fugacity between FMQ − 1.65 and FMQ + 0.05 (fayalite–magnetite–quartz). Each experiment consisted of five samples of basaltic composition (from the Hamn intrusion in Northern Norway) containing varying amounts of H2O (up to 2 wt %) and Cl (up to 1 wt %). The equilibrium experiments were used as a reference frame for the phase assemblage, geochemical composition, and liquidus temperatures and were compared to thermodynamic models using MELTS software. Experimental phase abundances and plagioclase compositions are in good agreement with the predictions of MELTS. The dynamic experiments were initially heated above the liquidus temperature to destroy crystal nuclei and then kept at 1150 ∘C for 100, 250, or 1800 min. These experiments show that as the concentration of H2O in the melt increases, plagioclase nucleation is delayed, plagioclase abundance decreases, but its size increases. Therefore, the addition of H2O seems to favor plagioclase growth at the expense of nucleation. Thermodynamic and kinetic calculations corroborate an increase in the nucleation delay of plagioclase with increasing H2O content dissolved in the melt, suggesting that H2O decreases the undercooling of the silicate melt. The addition of Cl also seems to delay plagioclase nucleation, although this is not supported by kinetic calculations. Increasing the Cl content decreases plagioclase abundance but does not significantly affect its size. The homogeneous pegmatitic pockets of the mafic–ultramafic Hamn intrusion exhibit several petrological and geochemical features, suggesting that H2O and Cl enrichment in the silicate melt was the origin of the pegmatitic texture. The experimental results presented here indicate that H2O, rather than Cl, may have played an important role in the formation of the pegmatitic texture. Article in Journal/Newspaper Northern Norway Niedersächsisches Online-Archiv NOA Norway Hamn ENVELOPE(13.415,13.415,66.689,66.689) European Journal of Mineralogy 35 6 1111 1124 |
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Open Polar |
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Niedersächsisches Online-Archiv NOA |
op_collection_id |
ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Heckmann, Paul Iacono-Marziano, Giada Strmić Palinkaš, Sabina An experimental study of the effect of water and chlorine on plagioclase nucleation and growth in mafic magmas: application to mafic pegmatites |
topic_facet |
article Verlagsveröffentlichung |
description |
In this study, the effects of H2O and Cl on the grain size and nucleation delay of plagioclase in basaltic magma were investigated using dynamic and equilibrium experiments at 1150 ∘C, 300 MPa, and oxygen fugacity between FMQ − 1.65 and FMQ + 0.05 (fayalite–magnetite–quartz). Each experiment consisted of five samples of basaltic composition (from the Hamn intrusion in Northern Norway) containing varying amounts of H2O (up to 2 wt %) and Cl (up to 1 wt %). The equilibrium experiments were used as a reference frame for the phase assemblage, geochemical composition, and liquidus temperatures and were compared to thermodynamic models using MELTS software. Experimental phase abundances and plagioclase compositions are in good agreement with the predictions of MELTS. The dynamic experiments were initially heated above the liquidus temperature to destroy crystal nuclei and then kept at 1150 ∘C for 100, 250, or 1800 min. These experiments show that as the concentration of H2O in the melt increases, plagioclase nucleation is delayed, plagioclase abundance decreases, but its size increases. Therefore, the addition of H2O seems to favor plagioclase growth at the expense of nucleation. Thermodynamic and kinetic calculations corroborate an increase in the nucleation delay of plagioclase with increasing H2O content dissolved in the melt, suggesting that H2O decreases the undercooling of the silicate melt. The addition of Cl also seems to delay plagioclase nucleation, although this is not supported by kinetic calculations. Increasing the Cl content decreases plagioclase abundance but does not significantly affect its size. The homogeneous pegmatitic pockets of the mafic–ultramafic Hamn intrusion exhibit several petrological and geochemical features, suggesting that H2O and Cl enrichment in the silicate melt was the origin of the pegmatitic texture. The experimental results presented here indicate that H2O, rather than Cl, may have played an important role in the formation of the pegmatitic texture. |
format |
Article in Journal/Newspaper |
author |
Heckmann, Paul Iacono-Marziano, Giada Strmić Palinkaš, Sabina |
author_facet |
Heckmann, Paul Iacono-Marziano, Giada Strmić Palinkaš, Sabina |
author_sort |
Heckmann, Paul |
title |
An experimental study of the effect of water and chlorine on plagioclase nucleation and growth in mafic magmas: application to mafic pegmatites |
title_short |
An experimental study of the effect of water and chlorine on plagioclase nucleation and growth in mafic magmas: application to mafic pegmatites |
title_full |
An experimental study of the effect of water and chlorine on plagioclase nucleation and growth in mafic magmas: application to mafic pegmatites |
title_fullStr |
An experimental study of the effect of water and chlorine on plagioclase nucleation and growth in mafic magmas: application to mafic pegmatites |
title_full_unstemmed |
An experimental study of the effect of water and chlorine on plagioclase nucleation and growth in mafic magmas: application to mafic pegmatites |
title_sort |
experimental study of the effect of water and chlorine on plagioclase nucleation and growth in mafic magmas: application to mafic pegmatites |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/ejm-35-1111-2023 https://noa.gwlb.de/receive/cop_mods_00070437 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00068786/ejm-35-1111-2023.pdf https://ejm.copernicus.org/articles/35/1111/2023/ejm-35-1111-2023.pdf |
long_lat |
ENVELOPE(13.415,13.415,66.689,66.689) |
geographic |
Norway Hamn |
geographic_facet |
Norway Hamn |
genre |
Northern Norway |
genre_facet |
Northern Norway |
op_relation |
European Journal of Mineralogy -- Eur.j.mineral -- http://www.bibliothek.uni-regensburg.de/ezeit/?2039451 -- http://eurjmin.geoscienceworld.org/ -- http://www.schweizerbart.de/j/ejm/index.html -- https://www.ingentaconnect.com/content/schweiz/ejm -- 1617-4011 https://doi.org/10.5194/ejm-35-1111-2023 https://noa.gwlb.de/receive/cop_mods_00070437 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00068786/ejm-35-1111-2023.pdf https://ejm.copernicus.org/articles/35/1111/2023/ejm-35-1111-2023.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/ejm-35-1111-2023 |
container_title |
European Journal of Mineralogy |
container_volume |
35 |
container_issue |
6 |
container_start_page |
1111 |
op_container_end_page |
1124 |
_version_ |
1788063927396990976 |