Grain-size dynamics beneath mid-ocean ridges: Implications for permeability and melt extraction

  title={Grain-size dynamics beneath mid-ocean ridges: Implications for permeability and melt extraction},
  author={A J Turner and Richard F. Katz and Mark Dietrich Behn},
  journal={Geochemistry, Geophysics, Geosystems : G(3)},
  pages={925 - 946}
Grain size is an important control on mantle viscosity and permeability, but is difficult or impossible to measure in situ. We construct a two‐dimensional, single phase model for the steady state mean grain size beneath a mid‐ocean ridge. The mantle rheology is modeled as a composite of diffusion creep, dislocation creep, dislocation accommodated grain boundary sliding, and a plastic stress limiter. The mean grain size is calculated by the paleowattmeter relationship of Austin and Evans (2007… 

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