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This dataset contains VASP runs performed on ARCHER to calculate the electrical and thermal conductivities of pure iron and iron alloys at Earth's core conditions using density functional theory with the Kubo-Greenwood formulation. Data are available for both the solid and the liquid phase characterising the inner and outer core respectively. Also included in the dataset the runs for computing the lattice contribution to the electrical resistivity of magnetic bcc iron at ambient pressure and two low temperatures and for computing the melting curve of fcc nickel. These data were also used for the modelling of the geodynamo and the thermal history of the Earth, to calculate the transport properties for silicon-oxygen-iron mixtures and to confirm the saturation of electrical resistivity of solid iron at Earth’s core conditions. The results from this dataset showed that both conductivities are much larger than previously thought with important implications for the geodynamo and the thermal history of the Earth, benefitting the geodynamo community. The results of our research have been recently confirmed by new experimental results obtained at Earth's core conditions. Further details can be found in Alfè et al. (2012); Pozzo et al. (2012, 2013a, 2013b, 2014, 2016); Gubbins et al. (2015); Davies et al. (2015). NERC Grant is NE/H02462X/1.
Friction coefficient and frictional stability (rate & state parameter) data for triaxially compressed direct shear experiments on kaolinite-rich china clay and Mg-montmorillonite fault gouges (<2micron grain size). A total of 19 raw experimental datasets are presented as detailed in the index files: 13 on kaolinite-rich china clay, and 6 on cation-exchanged Mg-Montmorillonite. The raw data files, logged at either 1 or 2Hz, comprise confining pressures, upstream and downstream fluid pressures, force experienced by the direct shear assembly during triaxial compression, and absolute volumes of the confining pressure and fluid pressure reservoirs. Data is provided as measured by gauges in the pressure vessel in Volts, and also as calculated in MPa, kN and mm3. Also presented are the outputs of MATLAB models run to simulate the rate and state parameters k, a, b, dc and f0 for each experiment, with error data presented as 2sigma and standard error values. Parameters were determined using a non-linear least-squares fitting routine with the machine stiffness treated as a fitting parameter (c.f. Noda and Shimamoto, 2009). Data were fit by a single set of state variables (a, b, dc) with a linear detrend. Also presented are the outputs of Specific Thermogravimetric Analyses on kaolinite-rich china clay and Mg-montmorillonite.