Comparison of the Sr isotopic signatures in brines of the Canadian and Fennoscandian shields
International audience A synthesis of Sr isotope data from shallow and deep groundwaters, and brines from the Fennoscandian and Canadian Shields is presented. A salinity gradient is evident in the water with concentrations varying from approximately 1–75 g L−1 below 1500 m depth in the Fennoscandian...
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ftccsdartic:oai:HAL:hal-03763145v1 2023-12-24T10:16:38+01:00 Comparison of the Sr isotopic signatures in brines of the Canadian and Fennoscandian shields Négrel, Philippe Casanova, Joël Bureau de Recherches Géologiques et Minières (BRGM) (BRGM) 2005-04 https://brgm.hal.science/hal-03763145 https://doi.org/10.1016/j.apgeochem.2004.11.010 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.apgeochem.2004.11.010 hal-03763145 https://brgm.hal.science/hal-03763145 doi:10.1016/j.apgeochem.2004.11.010 ISSN: 0883-2927 Applied Geochemistry https://brgm.hal.science/hal-03763145 Applied Geochemistry, 2005, 20 (4), pp.749-766. ⟨10.1016/j.apgeochem.2004.11.010⟩ [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2005 ftccsdartic https://doi.org/10.1016/j.apgeochem.2004.11.010 2023-11-26T00:03:08Z International audience A synthesis of Sr isotope data from shallow and deep groundwaters, and brines from the Fennoscandian and Canadian Shields is presented. A salinity gradient is evident in the water with concentrations varying from approximately 1–75 g L−1 below 1500 m depth in the Fennoscandian Shield and from 10 up to 300 g L−1 below 650 m depth in the Canadian Shield. Strontium isotope ratios were measured to assess the origin of the salinity and evaluate the degree of water–rock interaction in the systems. In both shields, the Sr concentrations are enriched relative to Cl, defining a positive trend parallel to the seawater dilution line and indicative of Sr addition through weathering processes. The depth distribution for Sr concentration increases strongly with increasing depth in both shields although the variation in Sr-isotope composition does not mirror that of Sr concentrations. Strontium-isotope compositions are presented for surface waters, and groundwaters in several sites in the Fennoscandian and Canadian Shields. Numerous mixing lines can be drawn reflecting water–rock interaction. A series of calculated lines links the surface end-members (surface water and shallow groundwater) and the deep brines; these mixing lines define a range of 87Sr/86Sr ratios for the deep brines in different selected sites. All sites show a specific 87Sr/86Sr signature and the occurrence of large 87Sr/86Sr variations is site specific in both shields. In Canadian Shield brines, the Sr isotope ratios clearly highlight large water rock interaction that increases the 87Sr/86Sr ratio from water that could have been of marine origin. In contrast to the Canadian Shield, groundwater does not occur in closed pockets in the Fennoscandian, and the well-constrained 87Sr/86Sr signatures in deep brines should correspond to a large, well-mixed and homogeneous water reservoir, whose Sr isotope signature results from water–rock interaction. Article in Journal/Newspaper Fennoscandian Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Applied Geochemistry 20 4 749 766 |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
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[SDU.STU]Sciences of the Universe [physics]/Earth Sciences Négrel, Philippe Casanova, Joël Comparison of the Sr isotopic signatures in brines of the Canadian and Fennoscandian shields |
topic_facet |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience A synthesis of Sr isotope data from shallow and deep groundwaters, and brines from the Fennoscandian and Canadian Shields is presented. A salinity gradient is evident in the water with concentrations varying from approximately 1–75 g L−1 below 1500 m depth in the Fennoscandian Shield and from 10 up to 300 g L−1 below 650 m depth in the Canadian Shield. Strontium isotope ratios were measured to assess the origin of the salinity and evaluate the degree of water–rock interaction in the systems. In both shields, the Sr concentrations are enriched relative to Cl, defining a positive trend parallel to the seawater dilution line and indicative of Sr addition through weathering processes. The depth distribution for Sr concentration increases strongly with increasing depth in both shields although the variation in Sr-isotope composition does not mirror that of Sr concentrations. Strontium-isotope compositions are presented for surface waters, and groundwaters in several sites in the Fennoscandian and Canadian Shields. Numerous mixing lines can be drawn reflecting water–rock interaction. A series of calculated lines links the surface end-members (surface water and shallow groundwater) and the deep brines; these mixing lines define a range of 87Sr/86Sr ratios for the deep brines in different selected sites. All sites show a specific 87Sr/86Sr signature and the occurrence of large 87Sr/86Sr variations is site specific in both shields. In Canadian Shield brines, the Sr isotope ratios clearly highlight large water rock interaction that increases the 87Sr/86Sr ratio from water that could have been of marine origin. In contrast to the Canadian Shield, groundwater does not occur in closed pockets in the Fennoscandian, and the well-constrained 87Sr/86Sr signatures in deep brines should correspond to a large, well-mixed and homogeneous water reservoir, whose Sr isotope signature results from water–rock interaction. |
author2 |
Bureau de Recherches Géologiques et Minières (BRGM) (BRGM) |
format |
Article in Journal/Newspaper |
author |
Négrel, Philippe Casanova, Joël |
author_facet |
Négrel, Philippe Casanova, Joël |
author_sort |
Négrel, Philippe |
title |
Comparison of the Sr isotopic signatures in brines of the Canadian and Fennoscandian shields |
title_short |
Comparison of the Sr isotopic signatures in brines of the Canadian and Fennoscandian shields |
title_full |
Comparison of the Sr isotopic signatures in brines of the Canadian and Fennoscandian shields |
title_fullStr |
Comparison of the Sr isotopic signatures in brines of the Canadian and Fennoscandian shields |
title_full_unstemmed |
Comparison of the Sr isotopic signatures in brines of the Canadian and Fennoscandian shields |
title_sort |
comparison of the sr isotopic signatures in brines of the canadian and fennoscandian shields |
publisher |
HAL CCSD |
publishDate |
2005 |
url |
https://brgm.hal.science/hal-03763145 https://doi.org/10.1016/j.apgeochem.2004.11.010 |
genre |
Fennoscandian |
genre_facet |
Fennoscandian |
op_source |
ISSN: 0883-2927 Applied Geochemistry https://brgm.hal.science/hal-03763145 Applied Geochemistry, 2005, 20 (4), pp.749-766. ⟨10.1016/j.apgeochem.2004.11.010⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.apgeochem.2004.11.010 hal-03763145 https://brgm.hal.science/hal-03763145 doi:10.1016/j.apgeochem.2004.11.010 |
op_doi |
https://doi.org/10.1016/j.apgeochem.2004.11.010 |
container_title |
Applied Geochemistry |
container_volume |
20 |
container_issue |
4 |
container_start_page |
749 |
op_container_end_page |
766 |
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1786204303729360896 |