title: Low-temperature plasticity of olivine revisited with in situ TEM nanomechanical testing.
abstract: The rheology of the lithospheric mantle is fundamental to understanding how mantle convection couples with plate tectonics. However, olivine rheology at lithospheric conditions is still poorly understood because experiments are difficult in this temperature range where rocks and mineral become very brittle. We combine techniques of quantitative in situ tensile testing in a transmission electron microscope and numerical modeling of dislocation dynamics to constrain the low-temperature rheology of olivine. We find that the intrinsic ductility of olivine at low temperature is significantly lower than previously reported values, which were obtained under strain-hardened conditions. Using this method, we can anchor rheological laws determined at higher temperature and can provide a better constraint on intermediate temperatures relevant for the lithosphere. More generally, we demonstrate the possibility of characterizing the mechanical properties of specimens, which can be available in the form of submillimeter-sized particles only.
authors.affiliation: Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.; Institute of Mechanics, Materials and Civil Engineering, Université catholique de Louvain, Place Sainte Barbe 2, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: Hosni
authors.initials: H
authors.lastname: Idrissi
authors.affiliation: Bayerisches Geoinstitut, University of Bayreuth, D-95440 Bayreuth, Germany.
authors.forename: Caroline
authors.initials: C
authors.lastname: Bollinger
authors.affiliation: Unité Matériaux et Transformations, UMR 8207 CNRS/Université Lille 1, F-59655 Villeneuve d'Ascq, France.
authors.forename: Francesca
authors.initials: F
authors.lastname: Boioli
authors.affiliation: Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
authors.forename: Dominique
authors.initials: D
authors.lastname: Schryvers
authors.affiliation: Unité Matériaux et Transformations, UMR 8207 CNRS/Université Lille 1, F-59655 Villeneuve d'Ascq, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Cordier
mesh_terms: D003080:Cold Temperature; D058085:Iron Compounds / Q000737:chemistry*; D017616:Magnesium Compounds / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D036103:Nanotechnology; D017640:Silicates / Q000737:chemistry*
chemical_list: D058085:Iron Compounds; D017616:Magnesium Compounds; D017640:Silicates; C034475:olivine
keywords: Earth sciences; dislocations; in situ TEM; mineral physics; olivine; plate tectonics; rheology