@article{7efa66827bf349ae9b28b8e83faa3825,
title = "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 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.",
keywords = "brucite, dehydration, excess pressure, fluid flux, multi-anvil, serpentine",
author = "L. Eberhard and M. Thielmann and P. Eichheimer and A. N{\'e}ri and A. Suzuki and M. Ohl and W. Fujita and K. Uesugi and M. Nakamura and Golabek, {G. J.} and Frost, {D. J.}",
note = "Funding Information: We thank Jos{\'e} Alberto Padr{\'o}n‐Navarta, two anonymous reviewers, and Editor Whitney Behr for their constructive comments that helped to improve the manuscript considerably. Hubert Schulze, Raphael Njul, and Alexander Rother are thanked for excellent sample preparation and Florian Heidelbach for the help with EBSD measurements. We thank Elias Kempf for providing the foliated antigorite‐serpentinite sample. The X‐ray tomography experiments were performed at SPring‐8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal nos. 2018A1471 and 2019B1785). This study was financed by the international research and training group Deep Earth Volatile Cycles DFG Grant No. GRK 2156/1 and partly supported by JSPS Japanese‐German Graduate Externship, DFG Grant Nos. FR1555/11, DFG Grant Nos. TH2076/8‐1, and the NWO Grant No. VI.Vidi.193.030. Open Access funding enabled and organized by Projekt DEAL. Funding Information: We thank Jos{\'e} Alberto Padr{\'o}n-Navarta, two anonymous reviewers, and Editor Whitney Behr for their constructive comments that helped to improve the manuscript considerably. Hubert Schulze, Raphael Njul, and Alexander Rother are thanked for excellent sample preparation and Florian Heidelbach for the help with EBSD measurements. We thank Elias Kempf for providing the foliated antigorite-serpentinite sample. The X-ray tomography experiments were performed at SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal nos. 2018A1471 and 2019B1785). This study was financed by the international research and training group Deep Earth Volatile Cycles DFG Grant No. GRK 2156/1 and partly supported by JSPS Japanese-German Graduate Externship, DFG Grant Nos. FR1555/11, DFG Grant Nos. TH2076/8-1, and the NWO Grant No. VI.Vidi.193.030. Open Access funding enabled and organized by Projekt DEAL. Publisher Copyright: {\textcopyright} 2022. The Authors.",
year = "2022",
month = sep,
doi = "10.1029/2021GC010062",
language = "English",
volume = "23",
journal = "Geochemistry, Geophysics, Geosystems",
issn = "1525-2027",
publisher = "American Geophysical Union",
number = "9",
}