From 1 - 10 / 10
  • Rheometry data on ash from Mt Meager, British Columbia, Canada. All measurements that generated these data were performed using an Anton Paar MCR302 rotational rheometer with an Anton Paar powder flow cell attached. The rotating measuring geometry is 24.16 mm in diameter and contains 20 evenly spaced depressions of 1.75 mm that extend the entire length of the measuring cylinder. The profiled nature of this geometry prevents particle slip during rotation. Shear rate sweeps were performed to characterise the rheological behaviour of our pyroclast-gas mixtures. ~50 g of sample (ash from Mt Meager, British Columbia, Canada) was loaded into the powder flow cell with the measuring geometry inserted. Then for a constant gas flux applied to the base of the powder flow cell, the measuring geometry was rotated to apply a range of shear rates starting at 0.1 s-1 ramping up to 328 s-1 with approximately 20 data points generated per decade. These shear rate sweeps were performed for monodisperse grain sizes from 500 µm to 63 µm at a range of volumetric gas flow rates. Specifically for the 500 µm sample the rheology experiments were performed at 0, 15, 30, 45, 50, 55, 60, 65, and 70 L min-1. For the 250 µm sample the rheology experiments were performed at 0, 15, 20, 25, 30, 35, and 40 L min-1. For the 125 µm sample the rheology experiments were performed at 0, 1, 2, 3, 4, 5, 7, 8, 9, and 10 L min-1. For the 63 µm sample the rheology experiments were performed at 0, 0.25, 0.5, 1, 1.5, 2, 3, 4, and 5 L min-1.

  • Synchrotron X-radiography (images) and diffraction data collected to measure rheology of Quartz coesite and stishovite.

  • The data consists of a spreadsheet containing rheology data for 39 samples of syrup, containing air bubbles and/or spherical glass particles. These data were used by Truby et al. (2014) to support a model for the rheology of a three-phase suspension. Each sample was placed in the rheometer (concentric cylinder geometry), and the stress was stepped up and then down, taking a measurement of strain rate at each step. Further details of the experiments may be found in Truby et al. (2014). NERC grant is NE/K500999/1. Co-author working with a NERC grant, NE/G014426/1.

  • Synchrotron X-radiography (images) and diffraction data collected to measure rheology of olivine and ringwoodite structured Co2SiO4.

  • Scanned and annotated thin sections, in plane-polarised and cross-polarised light. Derivative statistical data for mineral grainsize and spatial distribution.

  • Reconstructed data - This dataset contains the reconstructed image data. Each sub-folder contains a set of 2D slices that together make up a 3D image from that time point. Not all images from all datasets have been reconstructed, the values in parentheses refer to the scan numbers that have been reconstructed. Raw data - This dataset contains the raw unprocessed image data collected during the development of the XRheo system. Processed data - This dataset contains the post-processing outputs from analysis of the data from the XRheo development experiments. Each sub-folder contains the files generated during filtering, segmentation and separation of the features [M (melt), B (bubbles), X (crystals)], and the post processing analysis for size distributions and tracking. The data sets included are the results of dynamic X-ray tomography experiments performed on multiphase synthesised magmas being deformed under known temperature and strain rates for a concentric cylinder geometry.

  • Experimental mechanical data for single crystal shear experiments. Grant abstract: In 2011, NERC began a scoping exercise to develop a research programme based around deep Earth controls on the habitable planet. The result of this exercise was for NERC to commit substantial funding to support a programme entitled "Volatiles, Geodynamics and Solid Earth Controls on the Habitable Planet". This proposal is a direct response to that call. It is widely and generally accepted that volatiles - in particular water - strongly affect the properties that control the flow of rocks and minerals (their rheological properties). Indeed, experiments on low-pressure minerals such as quartz and olivine show that even small amounts of water can weaken a mineral - allowing it to flow faster - by as much as several orders of magnitude. This effect is known as hydrolytic weakening, and has been used to explain a wide range of fundamental Earth questions - including the origin of plate tectonics and why Earth and Venus are different. The effect of water and volatiles on the properties of mantle rocks and minerals is a central component of this NERC research programme. Indeed it forms the basis for one of the three main questions posed by the UK academic community, and supported by a number of international experts during the scoping process. The question is "What are the feedbacks between volatile fluxes and mantle convection through time?" Intuitively, one expects feedbacks between volatiles and mantle convection. For instance, one might envisage a scenario whereby the more water is subducted into the lower mantle, the more the mantle should weaken, allowing faster convection, which in turn results in even more water passing into the lower mantle, and so on. Of course this is a simplification since faster convection cools the mantle, slowing convection, and also increases the amount of volatiles removed from the mantle at mid-ocean ridges. Nevertheless, one can imagine many important feedbacks, some of which have been examined via simple models. In particular these models indicate a feedback between volatiles and convection that controls the distribution of water between the oceans and the mantle, and the amount topography created by the vertical movement of the mantle (known as dynamic topography). The scientists involved in the scoping exercise recognized this as a major scientific question, and one having potentially far reaching consequences for the Earth's surface and habitability. However, as is discussed in detail in the proposal, our understanding of how mantle rocks deform as a function of water content is remarkably limited, and in fact the effect of water on the majority of mantle minerals has never been measured. The effect of water on the flow properties of most mantle minerals is simply inferred from experiments on low-pressure minerals (olivine, pyroxenes and quartz). As argued in the proposal, one cannot simply extrapolate between different minerals and rocks because different minerals may react quite differently to water. Moreover, current research is now calling into question even the experimental results on olivine, making the issue even more pressing. We propose, therefore, a comprehensive campaign to quantify the effect of water on the rheological properties of all the major mantle minerals and rocks using a combination of new experiments and multi-physics simulation. In conjunction with 3D mantle convection models, this information will allow us to understand how the feedback between volatiles and mantle convection impacts on problems of Earth habitability, such as how ocean volumes and large-scale dynamic topography vary over time. This research thus addresses the aims and ambitions of the research programme head on, and indeed, is required for the success of the entire programme.

  • Scanned and annotated thin sections, in plane-polarised and cross-polarised light. Derivative statistical data for mineral grainsize and spatial distribution. Younger Giant Dyke, Tugtutoq, South Greenland.

  • This data contains the results of numerical simulations described in the following two papers: Alisic L., Rhebergen S., Rudge J.F., Katz R.F., Wells G.N. Torsion of a cylinder of partially molten rock with a spherical inclusion: theory and simulation (2016) Geochem. Geophys. Geosyst.16 doi:10.1002/2015GC006061 Alisic L., Rudge J.F., Katz R.F., Wells G.N., Rhebergen S. Compaction around a rigid, circular inclusion in partially molten rock (2014) J. Geophys. Res. Solid Earth 119:5903-5920 doi:10.1002/2013JB010906

  • Electron backscatter diffraction data for cumulates from the Skaergaard Intrusion of East Greenland. 12 samples from the Skaergaard Intrusion: 9 from the Layered Series, and 3 from the trough layering. Layered Series samples have a prefix LS; Trough layer samples have a prefix TB.