Lithium isotopes in hydrothermally altered basalts from Hengill (SW Iceland)
International audience The Li isotope signatures of hydrothermal fluids are remarkably constant (View the MathML sourceδLi7=8.0±1.9‰) irrespective of the water/rock ratio (W/RW/R), permeability, temperature or fluid involved (seawater or meteoric). High temperature hydrothermal fluids represent the...
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ftbrgm:oai:HAL:hal-01398995v1 2024-05-19T07:42:38+00:00 Lithium isotopes in hydrothermally altered basalts from Hengill (SW Iceland) Verney-Carron, Aurélie Vigier, Nathalie Millot, Romain Hardarson, B.S. Centre de Recherches Pétrographiques et Géochimiques (CRPG) Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS) Bureau de Recherches Géologiques et Minières (BRGM) Iceland GeoSurvey (ISOR ) 2015 https://brgm.hal.science/hal-01398995 https://doi.org/10.1016/j.epsl.2014.11.047 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2014.11.047 hal-01398995 https://brgm.hal.science/hal-01398995 doi:10.1016/j.epsl.2014.11.047 ISSN: 0012-821X Earth and Planetary Science Letters https://brgm.hal.science/hal-01398995 Earth and Planetary Science Letters, 2015, 411, pp.62 - 71. ⟨10.1016/j.epsl.2014.11.047⟩ lithium isotopes chemical weathering basalt hydrothermal fluids Iceland [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2015 ftbrgm https://doi.org/10.1016/j.epsl.2014.11.047 2024-05-02T00:19:54Z International audience The Li isotope signatures of hydrothermal fluids are remarkably constant (View the MathML sourceδLi7=8.0±1.9‰) irrespective of the water/rock ratio (W/RW/R), permeability, temperature or fluid involved (seawater or meteoric). High temperature hydrothermal fluids represent the second most significant source of Li to the ocean, yet the homogeneity of the Li isotopic signatures of this source remains to be explained and in this context, the lack of data for the corresponding altered phases is problematic. We measured Li contents and Li isotope signatures (as well as mineralogy, composition and local fluid temperature) in hyaloclastites collected from a borehole in the Hellisheidi geothermal system (Iceland) which have been altered by high temperature aqueous fluids (from 170 to 300 °C). Li is more enriched in the solid phases than the other alkali metals, highlighting its greater ability to be incorporated into secondary phases, especially at high temperatures (>250 °C). Mass balance calculations show that the low Li concentrations in hydrothermal fluids are best explained by a high water/rock ratio and a high permeability of this system. The Li isotopic signature of the altered hyaloclastites (View the MathML sourceδLi7 between +1.9 and +4.0‰+4.0‰) remains close to the fresh basalt at deep levels and high temperatures (290–300 °C) (as measured View the MathML sourceδLi7 range between +3.7 and +4.0‰+4.0‰), and decreases at shallower depths and lower temperatures (150–270 °C) (View the MathML sourceδLi7 between +1.9 and +3.1‰+3.1‰). A mass balance model involving basalt dissolution, secondary phase formation, and successive isotope equilibrium during the migration and the cooling of the percolating fluid was developed. The corresponding apparent mineral-fluid Li isotope fractionation factors resulting from precipitation of secondary phases (View the MathML sourceΔLiminerals-fluid7) range between 0‰ at 300 °C and −8.5‰−8.5‰ at 170 °C and highlight a key role of chlorite. Applying the same ... Article in Journal/Newspaper Iceland BRGM: HAL (Bureau de Recherches Géologiques et Minières) Earth and Planetary Science Letters 411 62 71 |
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Open Polar |
collection |
BRGM: HAL (Bureau de Recherches Géologiques et Minières) |
op_collection_id |
ftbrgm |
language |
English |
topic |
lithium isotopes chemical weathering basalt hydrothermal fluids Iceland [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
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lithium isotopes chemical weathering basalt hydrothermal fluids Iceland [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Verney-Carron, Aurélie Vigier, Nathalie Millot, Romain Hardarson, B.S. Lithium isotopes in hydrothermally altered basalts from Hengill (SW Iceland) |
topic_facet |
lithium isotopes chemical weathering basalt hydrothermal fluids Iceland [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience The Li isotope signatures of hydrothermal fluids are remarkably constant (View the MathML sourceδLi7=8.0±1.9‰) irrespective of the water/rock ratio (W/RW/R), permeability, temperature or fluid involved (seawater or meteoric). High temperature hydrothermal fluids represent the second most significant source of Li to the ocean, yet the homogeneity of the Li isotopic signatures of this source remains to be explained and in this context, the lack of data for the corresponding altered phases is problematic. We measured Li contents and Li isotope signatures (as well as mineralogy, composition and local fluid temperature) in hyaloclastites collected from a borehole in the Hellisheidi geothermal system (Iceland) which have been altered by high temperature aqueous fluids (from 170 to 300 °C). Li is more enriched in the solid phases than the other alkali metals, highlighting its greater ability to be incorporated into secondary phases, especially at high temperatures (>250 °C). Mass balance calculations show that the low Li concentrations in hydrothermal fluids are best explained by a high water/rock ratio and a high permeability of this system. The Li isotopic signature of the altered hyaloclastites (View the MathML sourceδLi7 between +1.9 and +4.0‰+4.0‰) remains close to the fresh basalt at deep levels and high temperatures (290–300 °C) (as measured View the MathML sourceδLi7 range between +3.7 and +4.0‰+4.0‰), and decreases at shallower depths and lower temperatures (150–270 °C) (View the MathML sourceδLi7 between +1.9 and +3.1‰+3.1‰). A mass balance model involving basalt dissolution, secondary phase formation, and successive isotope equilibrium during the migration and the cooling of the percolating fluid was developed. The corresponding apparent mineral-fluid Li isotope fractionation factors resulting from precipitation of secondary phases (View the MathML sourceΔLiminerals-fluid7) range between 0‰ at 300 °C and −8.5‰−8.5‰ at 170 °C and highlight a key role of chlorite. Applying the same ... |
author2 |
Centre de Recherches Pétrographiques et Géochimiques (CRPG) Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS) Bureau de Recherches Géologiques et Minières (BRGM) Iceland GeoSurvey (ISOR ) |
format |
Article in Journal/Newspaper |
author |
Verney-Carron, Aurélie Vigier, Nathalie Millot, Romain Hardarson, B.S. |
author_facet |
Verney-Carron, Aurélie Vigier, Nathalie Millot, Romain Hardarson, B.S. |
author_sort |
Verney-Carron, Aurélie |
title |
Lithium isotopes in hydrothermally altered basalts from Hengill (SW Iceland) |
title_short |
Lithium isotopes in hydrothermally altered basalts from Hengill (SW Iceland) |
title_full |
Lithium isotopes in hydrothermally altered basalts from Hengill (SW Iceland) |
title_fullStr |
Lithium isotopes in hydrothermally altered basalts from Hengill (SW Iceland) |
title_full_unstemmed |
Lithium isotopes in hydrothermally altered basalts from Hengill (SW Iceland) |
title_sort |
lithium isotopes in hydrothermally altered basalts from hengill (sw iceland) |
publisher |
HAL CCSD |
publishDate |
2015 |
url |
https://brgm.hal.science/hal-01398995 https://doi.org/10.1016/j.epsl.2014.11.047 |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
ISSN: 0012-821X Earth and Planetary Science Letters https://brgm.hal.science/hal-01398995 Earth and Planetary Science Letters, 2015, 411, pp.62 - 71. ⟨10.1016/j.epsl.2014.11.047⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2014.11.047 hal-01398995 https://brgm.hal.science/hal-01398995 doi:10.1016/j.epsl.2014.11.047 |
op_doi |
https://doi.org/10.1016/j.epsl.2014.11.047 |
container_title |
Earth and Planetary Science Letters |
container_volume |
411 |
container_start_page |
62 |
op_container_end_page |
71 |
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1799482336610353152 |