Skip to Main content Skip to Navigation
Journal articles

Olivine intergranular plasticity at mantle pressures and temperatures

Abstract : The ductile behavior of olivine-rich rocks is critical to constrain thermal convection in the Earth's upper mantle. Classical olivine flow laws for dislocation or diffusion creep fail to explain the fast post-seismic surface displacements observed by GPS, which requires a much weaker lithosphere than predicted by classical laws. Here we compare the plasticity of olivine aggregates deformed experimentally at mantle pressures and temperatures to that of single crystals and demonstrate that, depending on conditions of stress and temperature, strain accommodated through grain-to-grain interactions – here called intergranular strain – can be orders of magnitude larger than intracrystalline strain, which significantly weakens olivine strength. This result, extrapolated along mantle geotherms, suggests that intergranular plasticity could be dominant in most of the upper mantle. Consequently, the strength of olivine-rich aggregates in the upper mantle may be significantly lower than predicted by flow laws based on intracrystalline plasticity models.
Complete list of metadata
Contributor : Accord Elsevier Ccsd Connect in order to contact the contributor
Submitted on : Friday, October 22, 2021 - 8:59:41 PM
Last modification on : Friday, November 26, 2021 - 6:34:07 PM


Files produced by the author(s)


Distributed under a Creative Commons Attribution - NonCommercial - NoDerivatives 4.0 International License




Paul Raterron, Caroline Bollinger, Sébastien Merkel. Olivine intergranular plasticity at mantle pressures and temperatures. Comptes Rendus Géoscience, Elsevier, 2019, Comptes Rendus Geoscience, 351 (2-3), pp.80-85. ⟨10.1016/j.crte.2018.10.001⟩. ⟨hal-02168201⟩



Record views


Files downloads