EGU2020-1266
https://doi.org/10.5194/egusphere-egu2020-1266
EGU General Assembly 2020
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Instantaneous rock transformations in the deep crust driven by reactive fluid flow

Andreas Beinlich1, Timm John2, Johannes C. Vrijmoed2, Masako Tominaga3, Tomas Magna4, and Yuri Y. Podladchikov5
Andreas Beinlich et al.
  • 1University of Bergen, Department of Earth Science, Bergen, Norway
  • 2Freie Universität Berlin, Institut für Geologische Wissenschaften, Berlin, Germany
  • 3Woods Hole Oceanographic Institution, Woods Hole, USA
  • 4Czech Geological Survey, Prague, Czech Republic
  • 5University of Lausanne, Institute of Earth Sciences, Lausanne, Switzerland

Fluid–rock interactions link mass and energy transfer with large-scale tectonic deformation, drive the formation of mineral deposits, carbon sequestration, and rheological changes of the lithosphere. While spatial evidence indicates that fluid–rock interactions operate on length scales ranging from the grain boundary to tectonic plates, the timescales of regional fluid–rock interactions remain essentially unconstrained, despite being critically important for quantifying the duration of fundamental geodynamic processes. Here we show that reaction-induced transiently high permeability significantly facilitates fast fluid flow through low-permeability rock of the mid-crust. Using observations from an exceptionally well-exposed fossil hydrothermal system to inform a multi-element advective–diffusive–reactive transport model, we show that fluid-driven reaction fronts propagate with ~10 cm year-1, equivalent to the fastest tectonic plate motion and mid-ocean ridge spreading rates. Consequently, in the presence of reactive fluids, large-scale fluid-mediated rock transformations in continental collision and subduction zones occur on timescales of tens of years, implying that natural carbon sequestration, ore deposit formation, and transient and long-term petrophysical changes of the crust proceed, from a geological perspective, instantaneously.

How to cite: Beinlich, A., John, T., Vrijmoed, J. C., Tominaga, M., Magna, T., and Podladchikov, Y. Y.: Instantaneous rock transformations in the deep crust driven by reactive fluid flow, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1266, https://doi.org/10.5194/egusphere-egu2020-1266, 2020.