ScienceDirect The influence of hydrothermal activity on the Li isotopic signature of rivers draining volcanic areas
International audience We explore the geochemistry and the isotopic composition of lithium (δ 7 Li) of rivers draining volcanic islands (Guadeloupe, Iceland, Java, Martinique and Sao Miguel) with a specific focus on continental hydrothermal activity. Our preliminary results reveal a global-scale tre...
Published in: | Procedia Earth and Planetary Science |
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Main Authors: | , , , , , |
Other Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2014
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Subjects: | |
Online Access: | https://hal-insu.archives-ouvertes.fr/insu-01516076 https://hal-insu.archives-ouvertes.fr/insu-01516076/document https://hal-insu.archives-ouvertes.fr/insu-01516076/file/procedia-earth-henchiri-2014-10-223.pdf https://doi.org/10.1016/j.proeps.2014.08.026 |
Summary: | International audience We explore the geochemistry and the isotopic composition of lithium (δ 7 Li) of rivers draining volcanic islands (Guadeloupe, Iceland, Java, Martinique and Sao Miguel) with a specific focus on continental hydrothermal activity. Our preliminary results reveal a global-scale trend between δ 7 Li and the elemental ratio Li/Na in rivers draining volcanic islands. We suggest that this trend results from a mixture between waters with low δ 7 Li and high Li/Na, inherited from high-temperature water rock interactions, and waters with low Li/Na and high δ 7 Li, in which Li is controlled by the neoformation of clays during low-temperature chemical weathering in basaltic soils. This latter process can be described by a simple isotope fractionation model, consistent with reported values for isotopic fractionation factors between secondary weathering products and water. These data highlight the important potential role of continental high-temperature weathering processes on the oceanic budget of lithium. |
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