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    Data generated at UCL on a conventional triaxial apparatus used to deform three different sandstones at room temperature and 150 °C. The data includes the raw mechanical data (time, load, displacement, pore pressure, pore pressure volume and confining pressure) and the meaningful processed data used to plot figures and draw main conclusions (stress, strain, pore volume change, effective mean stress, inelastic strain, yield points and Youngs modulus). The three sandstones used were Bleursville, Locharbriggs and Boise Sandstone, and are denoted by data files SS, L and MBO respectively. This dataset is used in the paper: M. Jefferd, N. Brantut, P.G. Meredith and T.M. Mitchell, Compactive Deformation of Sandstone under Crustal Pressure and Temperature Conditionsserpentinite, submitted to J. Geophys. Res. And in the UCL PhD Thesis M.Jefferd, Sandstone under Crustal Pressure and Temperature

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    Oxygen and carbon isotope ratios (δ18O, δ13C) were measured on 10 to 12 shells of mixed-layer dwelling species Globigerinoides subquadratus from the 250 to 315 μm size fraction from 425 meters composite depth (mcd) until its extinction at 390 mcd. Analyses then continue with Globigerinoides spp. until 350 mcd. In a few samples, where foraminiferal density was low, only 5–7 specimens were analyzed. Analyses were made with a VG Optima mass spectrometer with multi prep device at the British Geological Survey, Keyworth, UK. When picking shells, care was taken to exclude individuals with broken or missing chambers, although preservation of specimens was generally excellent (Fox & Wade, 2013). The external reproducibility of our measurements is ±0.07‰ and ±0.05‰ for δ18O and δ13C respectively. To examine the reproducibility of the results, duplicate measurements were made on 35 samples (5%), which indicate mean reproducibility better than ±0.12‰ and ±0.14‰ for δ18O and δ13C, respectively. Oxygen isotope data are reported as per mil on the VPDB scale (Table S1) calibrated through laboratory and international standards. At ODP Site 1146, δ18O and δ13C were measured by Holbourn et al., (2010) on the mixed-layer dwelling planktonic foraminifera Globigerinoides obliquus or Gs. subquadratus, using 10 to 20 well-preserved tests from the size fraction 250-350 μm. Paired measurements in 51 samples indicate no significant offset in δ18O and δ13C between Gs. obliquus and Gs. subquadratus. Detailed methods are outlined in Holbourn et al., (2010). δ13C data are not used here. For Mg/Ca analyses, we selected 25–35 specimens of Trilobatus quadrilobatus (140–550 μg) from the 250 to 315 μm size fraction; the same size fraction as used for δ18O analysis, to minimize size-related intraspecific elemental variation (Elderfield et al., 2002). Analyses were performed on 86 samples over the studied interval. The tests were gently crushed and subsequently cleaned according to the protocol of Martin & Lea (2002) to remove clays. Cleaning included a reductive step with hydrazine to remove Mn-(hydr)oxides. Samples were measured on an ICP-AES device at Christian-Albrechts-Universität zu Kiel, Germany. Analytical precision is ~1.1%, based on measurements of an internal laboratory standard. Replicate Mg/Ca measurements revealed an average standard deviation of ~0.08 mmol/mol. Adequate cleaning is indicated by very low Fe/Ca, Al/Ca and Mn/Ca ratios.

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    Electronic Supplementary Material: "Event trees and epistemic uncertainty in long-term volcanic hazard assessment of rift volcanoes: the example of Aluto (Central Ethiopia)", by Tierz, P., Clarke, B., Calder, E. S., Dessalegn, F., Lewi, E., Yirgu, G., Fontijn, K., Crummy, J. M., and Loughlin, S. C., submitted to Geochemistry, Geophysics, Geosystems. The datasets contain volcanological data on analogue (i.e. similar) volcanoes of Aluto volcano (Ethiopia), including conditional probabilities of eruption size, number of eruptions with specific volcanic phenomena reported and values of volcano analogy calculated using the VOLCano ANalogues Search tool (VOLCANS, Tierz et al., 2019, https://doi.org/10.1007/s00445-019-1336-3). These type of data can be used to parameterise event tree models (e.g. Newhall and Hoblitt, 2002, https://doi.org/10.1007/s004450100173; Marzocchi et al., 2010, https://doi.org/10.1007/s00445-010-0357-8) and, thus, quantify volcanic hazard at a particular volcano of interest, including the relevant sources of uncertainty. The production of the datasets was supported by the UK Natural Environment Research Council project: Rift Volcanism: Past, Present and Future (RiftVolc). Grant NE/L013460/1.

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    The data are from a suite of friction experiments performed on simulated fault gouges comprised of clay-quartz mixtures, sheared in a direct-shear arrangement. Some experiments were performed on gouge layers comprised of adjacent patches of kaolinite-clay and quartz (i.e. heterogeneous gouge layers), whereas others were performed on homogeneous mixtures of the two materials (i.e. homogeneous gouge layers). More information on the different types of experiment is provided in the accompanying metadata for this dataset. The relative proportions of clay and quartz were varied in different experiments. All experiments were performed at an effective normal stress of 40 MPa. The sliding velocity was stepped between 0.3 and 3 microns/s every 1 mm of displacement to calculated the rate-and-state friction parameter (a-b). The evolution of shear stress was monitored with increasing displacement (up to a maximum displacement of 8.5 mm).

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    This dataset contains a catalogue of in-situ models for a fault activated by hydraulic fracturing in the Horn River Basin in July 2011. These were created as a part of Kettlety et al. (2019), wherein a Monte Carlo analysis was used to assess fault stability. See attached readme file for more details.

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    The data are from a suite of friction experiments performed on simulated gouges from the Nankai Trough (Japan). The simulated gouges were prepared by crushing cuttings of Nankai accretionary sediments collected during Integrated Ocean Drilling Program (IODP) Expedition 358. The cuttings were crushed to produce a powder (i.e. simulated gouge) with a grain size of >125 microns. These simulated gouges were sheared under a range of effective normal stress (10-75 Mpa) and pore-fluid pressure (5-75 Mpa) conditions while the sliding velocity was stepped between 0.3 and 3 microns/s to calculated the rate-and-state friction parameter (a-b). The Nankai gouge are strongly rate-strengthening and become more rate-strengthening (i.e. more frictionally stable) at elevated pore-fluid pressure. In contrast, varying the effective normal stress has minimal effect on the frictional stability of the gouges.

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    This data set contains a record of nitrate concentrations and isotopic composition present within the drip waters and speleothem carbonate deposits of Cueva-cubío del Llanío, northern Spain. Data were collected between 2018 to 2020, and specifically address the nitrate composition of the cave drip waters, pool waters, rocks, soil, vegetation and contemporary speleothem carbonate. Calculations are also undertaken to assess the partitioning of nitrate between cave drip water and speleothem carbonate deposits. Data pertaining to speleothem nitrate content also extend to other cave locations (Pooles cavern, UK; Brown's Folly Mine, UK, Ease Gill Caverns, UK; Rukiesa cave, Ethiopia; Cueva Perlas, N. Spain). Sample analysis was performed at Lancaster University and the UK Centre for Ecology and Hydrology under NERC facility access grant LSMSF\CEH\L\125\11\2018. The data presented represent the full underlying dataset to Wynn et al., 2021, Chemical Geology: DOI.org/10.1016/j.chemgeo.2021.120172.

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    Data produced during three BGS ground gas surveys (August 2018, and May and October 2019) of up to 83 point measurements across four pre-determined locations within the UK Geoenergy Observatories (UKGEOS) Glasgow site, located to the south of the Cuningar Loop Woodland Park. The dataset includes measurements of CH4 and CO2 flux between the ground surface and lower atmosphere, along with concentrations of CO2, O2, H2, H2S and ‘residual balance’ in near surface ground gas measured at c.70 cm below ground level. Further details about the dataset can be found in the accompanying report. http://nora.nerc.ac.uk/id/eprint/528737/

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    Data are distances (in cm) to water measured by an experimental near-infrared lidar sensor in six different setups (2017–9). Laboratory tests conducted at Imperial College London include quantifying the effect of (i) distance, (ii) sensor inclination, (iii) turbidity/clarity of the water, and (iv) ambient temperature on measurement bias. Outdoor tests at three locations in London interrogated the effect of varying water surface roughness on the measurements. A dataset of high-frequency measurements is also included, from which the effects of sample autocorrelation were interrogated.

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    This is supporting data for the manuscript entitled 'DFENS: Diffusion chronometry using Finite Elements and Nested Sampling' by E. J. F. Mutch, J. Maclennan, O. Shorttle, J. F. Rudge and D. Neave. Preprint here: https://doi.org/10.1002/essoar.10503709.1 Data Set S1. ds01.csv Electron probe microanalysis (EPMA) profile data of olivine crystals used in this study. Standard deviations are averaged values of standard deviations from counting statistics and repeat measurements of secondary standards. Data Set S2. ds02.csv Plagioclase compositional profiles used in this study, including SIMS, EPMA and step scan data. Standard deviations for EPMA analyses are averaged values of standard deviations from counting statistics and repeat measurements of secondary standards. Standard deviations for SIMS and step scan analyses are based on analytical precision of secondary standards. Data Set S3. ds03.csv Angles between the EPMA profile and the main olivine crystallographic axes measured by electron backscatter diffraction (EBSD). 'angle100X' is the angle between the [100] crystallographic axis and the x direction of the EBSD map, 'angle100Y' is the angle between [100] crystallographic axis and the y direction of the EBSD map, and 'angle100Z' is the angle between the [100] crystallographic axis and the z direction in the EBSD map etc. 'angle100P' is the angle between the EPMA profile and the [100] crystallographic axis, 'angle010P' is the angle between the EPMA profile and the [010] crystallographic axis, and 'angle100P' is the angle between the EPMA profile and the [001] crystallographic axis. All angles are in degrees. Data Set S4. ds04.csv Median timescales and 1 sigma errors from the olivine crystals of this study. The +1 sigma (days) is the quantile value calculated at 0.841 (i.e. 0.5 + (0.6826 / 2)). The -1 sigma (days) is therefore the quantile calculated at approximately 0.158 (which is 1 - 0.841). The 2 sigma is basically the same but it is 0.5 + (0.95/2). The value quoted as the +1 sigma (error) is the difference between the upper 1 sigma quantile and the median. Likewise the -1 sigma (error) is the difference between the median and the lower 1 sigma quantile. Data Set S5. ds05.xlsx Median timescales and 1 sigma errors from the plagioclase crystals of this study. Results from each of the parameterisations of the Mg-in-plagioclase diffusion data are included: Faak et al, (2013), Van Orman et al., (2014) and a combined expression. Data Set S6. ds06.xlsx Spreadsheet containing the regression parameters and covariance matrices used in this study and in Mutch et al. (2019). Additional versions of the olivine regressions where the ln fO2 is expressed in Pa have been made for completeness. We recommend using the versions where ln fO2 is expressed in its native form (bars).