A New Method for Determining Fluid Flux at High Pressures Applied to the Dehydration of Serpentinites
Abstract A new method to determine fluid flux at high pressures and temperatures has been developed and used to study serpentinites at subduction zone conditions. Drill cores of a natural antigorite‐serpentinite with a strong foliation were used in multi‐anvil experiments in the range of 2–5 GPa and...
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| Format: | Article |
| Language: | English |
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Wiley
2022-09-01
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| Series: | Geochemistry, Geophysics, Geosystems |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2021GC010062 |
| _version_ | 1827771570063409152 |
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| author | L. Eberhard M. Thielmann P. Eichheimer A. Néri A. Suzuki M. Ohl W. Fujita K. Uesugi M. Nakamura G. J. Golabek D. J. Frost |
| author_facet | L. Eberhard M. Thielmann P. Eichheimer A. Néri A. Suzuki M. Ohl W. Fujita K. Uesugi M. Nakamura G. J. Golabek D. J. Frost |
| author_sort | L. Eberhard |
| collection | DOAJ |
| description | Abstract A new method to determine fluid flux at high pressures and temperatures has been developed and used to study serpentinites at subduction zone conditions. Drill cores of a natural antigorite‐serpentinite with a strong foliation were used in multi‐anvil experiments in the range of 2–5 GPa and 450–800°C. Fluids released upon dehydration are fixed by the formation of brucite in an adjacent fluid sink. The amount and distribution of brucite serves as a proxy for fluid flow. In our specific setup the sample reacted with the surrounding fluid sink to form an additional layer of olivine, which has the potential to limit fluid flux within our experiments. For conditions prior to serpentine dehydration we used Al(OH)3 as fluid source. Fluid in this experiment did not migrate through the serpentinite, indicating that serpentine has a low diffusivity. The experiments also show that small deviatoric stresses have an influence on the fluid flux and can cause an anisotropic fluid flux. Comparison between the time scales of the determined fluid flux with fluid production rates indicates fluid pressure buildup during dehydration reactions. Adjacent less permeable layers can inhibit fluid flux and cause fluid pressure buildup even at conditions when an interconnected pore space formed. |
| first_indexed | 2024-03-11T12:56:06Z |
| format | Article |
| id | doaj.art-012bdb02f63c41ffbaa84b4fb4a4c443 |
| institution | Directory Open Access Journal |
| issn | 1525-2027 |
| language | English |
| last_indexed | 2024-03-11T12:56:06Z |
| publishDate | 2022-09-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geochemistry, Geophysics, Geosystems |
| spelling | doaj.art-012bdb02f63c41ffbaa84b4fb4a4c4432023-11-03T17:00:51ZengWileyGeochemistry, Geophysics, Geosystems1525-20272022-09-01239n/an/a10.1029/2021GC010062A New Method for Determining Fluid Flux at High Pressures Applied to the Dehydration of SerpentinitesL. Eberhard0M. Thielmann1P. Eichheimer2A. Néri3A. Suzuki4M. Ohl5W. Fujita6K. Uesugi7M. Nakamura8G. J. Golabek9D. J. Frost10Bayerisches Geoinstitut University of Bayreuth Bayreuth GermanyBayerisches Geoinstitut University of Bayreuth Bayreuth GermanyBayerisches Geoinstitut University of Bayreuth Bayreuth GermanyBayerisches Geoinstitut University of Bayreuth Bayreuth GermanyDepartment of Earth Science Tohoku University Sendai JapanDepartment of Earth Sciences Utrecht University Utrecht The NetherlandsDepartment of Earth Science Tohoku University Sendai JapanJapan Synchrotron Radiation Research Institute (JASRI/Spring‐8) Hyogo JapanDepartment of Earth Science Tohoku University Sendai JapanBayerisches Geoinstitut University of Bayreuth Bayreuth GermanyBayerisches Geoinstitut University of Bayreuth Bayreuth GermanyAbstract A new method to determine fluid flux at high pressures and temperatures has been developed and used to study serpentinites at subduction zone conditions. Drill cores of a natural antigorite‐serpentinite with a strong foliation were used in multi‐anvil experiments in the range of 2–5 GPa and 450–800°C. Fluids released upon dehydration are fixed by the formation of brucite in an adjacent fluid sink. The amount and distribution of brucite serves as a proxy for fluid flow. In our specific setup the sample reacted with the surrounding fluid sink to form an additional layer of olivine, which has the potential to limit fluid flux within our experiments. For conditions prior to serpentine dehydration we used Al(OH)3 as fluid source. Fluid in this experiment did not migrate through the serpentinite, indicating that serpentine has a low diffusivity. The experiments also show that small deviatoric stresses have an influence on the fluid flux and can cause an anisotropic fluid flux. Comparison between the time scales of the determined fluid flux with fluid production rates indicates fluid pressure buildup during dehydration reactions. Adjacent less permeable layers can inhibit fluid flux and cause fluid pressure buildup even at conditions when an interconnected pore space formed.https://doi.org/10.1029/2021GC010062fluid fluxmulti‐anvilserpentinebrucitedehydrationexcess pressure |
| spellingShingle | L. Eberhard M. Thielmann P. Eichheimer A. Néri A. Suzuki M. Ohl W. Fujita K. Uesugi M. Nakamura G. J. Golabek D. J. Frost A New Method for Determining Fluid Flux at High Pressures Applied to the Dehydration of Serpentinites Geochemistry, Geophysics, Geosystems fluid flux multi‐anvil serpentine brucite dehydration excess pressure |
| title | A New Method for Determining Fluid Flux at High Pressures Applied to the Dehydration of Serpentinites |
| title_full | A New Method for Determining Fluid Flux at High Pressures Applied to the Dehydration of Serpentinites |
| title_fullStr | A New Method for Determining Fluid Flux at High Pressures Applied to the Dehydration of Serpentinites |
| title_full_unstemmed | A New Method for Determining Fluid Flux at High Pressures Applied to the Dehydration of Serpentinites |
| title_short | A New Method for Determining Fluid Flux at High Pressures Applied to the Dehydration of Serpentinites |
| title_sort | new method for determining fluid flux at high pressures applied to the dehydration of serpentinites |
| topic | fluid flux multi‐anvil serpentine brucite dehydration excess pressure |
| url | https://doi.org/10.1029/2021GC010062 |
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