title: The effect of rock particles and D2O replacement on the flow behaviour of ice.
abstract: Ice-rock mixtures are found in a range of natural terrestrial and planetary environments. To understand how flow processes occur in these environments, laboratory-derived properties can be extrapolated to natural conditions through flow laws. Here, deformation experiments have been carried out on polycrystalline samples of pure ice, ice-rock and D2O-ice-rock mixtures at temperatures of 263, 253 and 233 K, confining pressure of 0 and 48 MPa, rock fraction of 0-50 vol.% and strain-rates of 5 × 10-7to 5 × 10-5s-1Both the presence of rock particles and replacement of H2O by D2O increase bulk strength. Calculated flow law parameters for ice and H2O-ice-rock are similar to literature values at equivalent conditions, except for the value of the rock fraction exponent, here found to be 1. D2O samples are 1.8 times stronger than H2O samples, probably due to the higher mass of deuterons when compared with protons. A gradual transition between dislocation creep and grain-size-sensitive deformation at the lowest strain-rates in ice and ice-rock samples is suggested. These results demonstrate that flow laws can be found to describe ice-rock behaviour, and should be used in modelling of natural processes, but that further work is required to constrain parameters and mechanisms for the observed strength enhancement.This article is part of the themed issue 'Microdynamics of ice'.
authors.affiliation: Laboratoire de Glaciologie, Université Libre de Bruxelles (ULB), CP 160/03, 50 Avenue F.D. Roosevelt, 1050 Brussels, Belgium ceri.middleton@ulb.ac.be.|Non Linear Physical Chemistry Unit, Université Libre de Bruxelles (ULB), Boulevard du Triomphe, 1050 Brussels, Belgium.|Centre for Planetary Sciences at UCL/Birkbeck, University College London, Gower Street, London WC1E 6BT, UK.|Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: Ceri A
authors.identifier: http://orcid.org/0000-0001-9488-9717
authors.initials: CA
authors.lastname: Middleton
authors.affiliation: Centre for Planetary Sciences at UCL/Birkbeck, University College London, Gower Street, London WC1E 6BT, UK.|Department of Earth and Planetary Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Grindrod
authors.affiliation: Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: Peter R
authors.identifier: http://orcid.org/0000-0003-3355-6761
authors.initials: PR
authors.lastname: Sammonds
keywords: D2O-ice–rock rheology; ice–rock flow laws; ice–rock rheology; triaxial deformation