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    The effect of rock particles and D2O replacement on the flow behaviour of ice

    Middleton, C.A. and Grindrod, Peter and Sammonds, P.R. (2017) The effect of rock particles and D2O replacement on the flow behaviour of ice. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 375 (2086), ISSN 1364-503X.

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    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 × 10−7 to 5 × 10−5 s−1. Both 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.

    Metadata

    Item Type: Article
    Additional Information: Theme issue “Microdynamics of ice” compiled and edited by Peter Sammonds, Maurine Montagnat and Martin Schneebeli
    Keyword(s) / Subject(s): ice–rock rheology, triaxial deformation, D2O-ice–rock rheology, ice–rock flow laws
    School: Birkbeck Schools and Departments > School of Science > Earth and Planetary Sciences > UCL/Birkbeck Centre for Planetary Sciences
    Birkbeck Schools and Departments > School of Science > Earth and Planetary Sciences
    Depositing User: Peter Grindrod
    Date Deposited: 25 Jan 2017 12:02
    Last Modified: 27 Dec 2017 01:10
    URI: http://eprints.bbk.ac.uk/id/eprint/15732

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