The behaviour of metals in deep fluids of NE Iceland
Abstract In this contribution, we present some of the first data on the elemental signature of deep crustal fluids in a basalt-hosted, low-chloride magmatic-hydrothermal system. Down-hole fluid samples (850–1600 m) from wells in the Theistareykir and Krafla geothermal fields in the Northern Volcanic...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2022-12-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-022-26028-x |
| _version_ | 1797977555562659840 |
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| author | Marion Saby Vincent van Hinsberg Daniele L. Pinti Kim Berlo Bjarni Gautason Ásgerður Sigurðardóttir Kevin Brown Océane Rocher |
| author_facet | Marion Saby Vincent van Hinsberg Daniele L. Pinti Kim Berlo Bjarni Gautason Ásgerður Sigurðardóttir Kevin Brown Océane Rocher |
| author_sort | Marion Saby |
| collection | DOAJ |
| description | Abstract In this contribution, we present some of the first data on the elemental signature of deep crustal fluids in a basalt-hosted, low-chloride magmatic-hydrothermal system. Down-hole fluid samples (850–1600 m) from wells in the Theistareykir and Krafla geothermal fields in the Northern Volcanic Zone of Iceland were combined with well-head samples of condensed vapor, cuttings of altered rock, and fresh basalt (being some of the first concentration data for volatile and semi-volatile elements (Sb, Tl, Bi, Cd and As) for this area of Iceland). Results show that the deep fluids are relatively enriched in base metals and (semi)-volatile metals (in particular Te, Hg, Re and Tl) compared to local basalt. We interpret this enrichment in volatile metals to reflect a significant element input from magma degassing. Boiling of this deep fluid results in a well-head fluid composition that is significantly depleted in most elements. This well-head fluid has a distinct elemental signature, including a depletion in Sb that is mirrored in the altered rocks, and a depletion in the base metals that shows their selective sequestration in scale minerals, likely sulphides. As expected, the element content and patterns in surface fluids can thus not be interpreted to directly reflect that of the deep reservoir fluid. The behaviour of elements in Theistareykir and Krafla fluids is consistent, and largely agrees with similar data obtained for the Reykjanes geothermal system in SW Iceland. We therefore posit that our results are representative for this geological setting and indicate a significant magmatic degassing cation input to deep fluids, variably modified by water–rock interaction. |
| first_indexed | 2024-04-11T05:08:50Z |
| format | Article |
| id | doaj.art-ae4dbe6223dc4efc89f36e7177e51a5b |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-04-11T05:08:50Z |
| publishDate | 2022-12-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-ae4dbe6223dc4efc89f36e7177e51a5b2022-12-25T12:11:30ZengNature PortfolioScientific Reports2045-23222022-12-0112111110.1038/s41598-022-26028-xThe behaviour of metals in deep fluids of NE IcelandMarion Saby0Vincent van Hinsberg1Daniele L. Pinti2Kim Berlo3Bjarni Gautason4Ásgerður Sigurðardóttir5Kevin Brown6Océane Rocher7GEOTOP and Département des Sciences de la Terre et de l’atmosphère, Université du Québec à MontréalGEOTOP and Department of Earth and Planetary Sciences, McGill UniversityGEOTOP and Département des Sciences de la Terre et de l’atmosphère, Université du Québec à MontréalGEOTOP and Department of Earth and Planetary Sciences, McGill UniversityÍSOR Iceland GeoSurvey, OrkugardurLandsvirkjunGeokemGeoRessources - UMR 7359, Université de LorraineAbstract In this contribution, we present some of the first data on the elemental signature of deep crustal fluids in a basalt-hosted, low-chloride magmatic-hydrothermal system. Down-hole fluid samples (850–1600 m) from wells in the Theistareykir and Krafla geothermal fields in the Northern Volcanic Zone of Iceland were combined with well-head samples of condensed vapor, cuttings of altered rock, and fresh basalt (being some of the first concentration data for volatile and semi-volatile elements (Sb, Tl, Bi, Cd and As) for this area of Iceland). Results show that the deep fluids are relatively enriched in base metals and (semi)-volatile metals (in particular Te, Hg, Re and Tl) compared to local basalt. We interpret this enrichment in volatile metals to reflect a significant element input from magma degassing. Boiling of this deep fluid results in a well-head fluid composition that is significantly depleted in most elements. This well-head fluid has a distinct elemental signature, including a depletion in Sb that is mirrored in the altered rocks, and a depletion in the base metals that shows their selective sequestration in scale minerals, likely sulphides. As expected, the element content and patterns in surface fluids can thus not be interpreted to directly reflect that of the deep reservoir fluid. The behaviour of elements in Theistareykir and Krafla fluids is consistent, and largely agrees with similar data obtained for the Reykjanes geothermal system in SW Iceland. We therefore posit that our results are representative for this geological setting and indicate a significant magmatic degassing cation input to deep fluids, variably modified by water–rock interaction.https://doi.org/10.1038/s41598-022-26028-x |
| spellingShingle | Marion Saby Vincent van Hinsberg Daniele L. Pinti Kim Berlo Bjarni Gautason Ásgerður Sigurðardóttir Kevin Brown Océane Rocher The behaviour of metals in deep fluids of NE Iceland Scientific Reports |
| title | The behaviour of metals in deep fluids of NE Iceland |
| title_full | The behaviour of metals in deep fluids of NE Iceland |
| title_fullStr | The behaviour of metals in deep fluids of NE Iceland |
| title_full_unstemmed | The behaviour of metals in deep fluids of NE Iceland |
| title_short | The behaviour of metals in deep fluids of NE Iceland |
| title_sort | behaviour of metals in deep fluids of ne iceland |
| url | https://doi.org/10.1038/s41598-022-26028-x |
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