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

Field photographs of rock formations or modern precipitates from the sedimentary environment. Samples were collected throughout the UK. This data was collected between February 2019 and November 2019. This data was collected to better understand the low temperature cycling of Telurium (Te) and Sellenium (Se) in the geological environment. For example, a range of ochre samples were included in this data. Ochres are a modern precipitate commonly found in rivers and streams which flow through geographical areas with a history of mining resources which are rich in sulphides. Iron from the sulphides are leached out and deposited downstream, coating river and stream beds, giving a red, yellow or orange colouration. Ochres can be a sink for trace metals such as Te and Se, therefore studying these environments could be informative from a resource perspective but also from an environmental hazard perspective. This data would be useful for researchers who require reference photographs for similar studies or as an aid for resampling.

Data recorded during hydrostatic pressurisation and triaxial rock deformation experiments of Westerly granite and Darley Dale sandstone. Data consists of mechanical data (load, displacement, confining pressure) and pore pressure data (up- and downstream pore pressure, upstream intensifier volume, four pore pressure transducers mounted on sample). Contains all data necessary to evaluate the results presented in the paper entitled: 'Fluid pressure heterogeneity during fluid flow in rocks: New laboratory measurement device and method' by Brantut and Aben, submitted to Geophysical Journal International, and available at arXiv (arXiv:2006.16699).

X-ray CT scan dataset of Darley Dale sandstone sample tts6. This sample was deformed in a true triaxial apparatus, and is fully described in the PhD thesis of Stuart (1992, UCL). The sample is a cube, measuring approximately 50 mm on a side. The sample experienced two sets of true triaxial deformation (test DDSS0009 and DDSS0010), with different applied stresses in the 1, 2 and 3 directions. This deformation produced distinct families of brittle microcracks, which were detected using acoustic emissions and seismic velocity analysis. This X-ray CT scan dataset was collected in 2019 at the University of Aberdeen by Dr Stewart Chalmers and Dr Dave Healy.

Loan IDA number IDA271576. Microbial DNA concentrations from DNA extraction using Qiagen PowerSoil Pro DNA Extraction kit and subsequent PCR from shale and sandstone core samples collected and preserved for microbiology (shale SSK111456 and sandstone SSK111457) from UKGEOS Glasgow Observatory, borehole GGC01. DNA extractions and subsequent amplification using PCR indicate levels of microbial DNA below detection limits. Samples and data are derived from the UK Geoenergy Observatories Programme funded by the UKRI Natural Environment Research Council and delivered by the British Geological Survey.

The dataset describes the results of high pressure experimental measurements of three contrasting 'tight' rocks; a Bowland Shale, a Haynesville shale and Pennant sandstone. The results are tabulated as a csv file, listing experimental parameters, confining pressure, argon gas pore pressure and permeability. complementary measurements of key petrophysical data are provided - bulk modulus of compressibility, porosity TOC and density.

These images were acquired using micro computed tomographic imaging of 7 sandstone plugs taken at various depths in the Sellafield borehole 13B. SF696 (63.8 m), SF697 (76.1 m), SF698 (96.98 m), SF699 (126.27 m), SF700 (144.03 m), SF701 (172.16 m) and SF702 (181.39 m). These samples are further detailed and analysed in the following article: http://dx.doi.org/10.1144/petgeo2020-092

The spreadsheet gathers the data collected during a brine:CO2 flow-through experiment conducted on a weakly-cemented synthetic sandstone core sample using the multiflow experimental rig for CO2 experiments, designed and assembled at the National Oceanography Centre, Southampton. The test was configured to assess geophysical monitoring and deformation of reservoirs subjected to CO2 injection in shallow weakly-cemented (North Sea-like, e.g., Sleipner) CO2 storage sandstone reservoirs. The tests was conducted in the rock physics laboratory at the National Oceanography Centre, Southampton, during 2015-2016, as part of the DiSECCS project with funding from the United Kingdom’s Engineering and Physical Sciences Research Council (EPSRC grant EP/K035878/1) and the Natural Environment Research Council (NERC). The experiment was a steady state brine-CO2 flow-through test in which realistic shallow CO2 geosequestration conditions were simulated, to related geophysical signatures to the hydrodynamic and geomechanical behaviour of the rock sample. The confining and pore pressure conditions were similar to those estimated for shallow North Sea Sleipner-like, storage reservoirs, but simulating inflation/depletion cyclic scenarios for increasing brine:CO2 fractional flow rates. The data include ultrasonic P- and S-wave velocities and their respective attenuation factors, axial, radial and volumetric strains, and electrical resistivity; also relative permeability to both fluids (CO2 and brine) is displayed as a function of pore volume times, associated to increasing CO2 to brine contents in the sample.

These images were acquired using micro computed tomographic imaging of 4 sandstone plugs taken at various depths in the Glasgow UKGEOS borehole GGC01. GG496 (170.07 m), GG497 (168.66 m), GG498 (73.37 m) and GG499 (135.06 m). These samples are further detailed and analysed in the following article: http://dx.doi.org/10.1144/petgeo2020-092.

This dataset is of laboratory ultrasonic shear wave measurements during methane hydrate formation in water saturated Berea sandstone using pulse echo method. We formed methane hydrate and took shear wave measurements during the formation process at different time interval. The hydrate saturation was calculated from measured pressure and temperature changes. This data set was used to show how shear wave velocity and attenuation can be used to estimate permeability of hydrate-bearing geological formations. We observed that velocity and attenuation both increase with hydrate saturation, with two peaks in attenuation at hydrate saturations of around 6% and 20% that correspond to changes in gradient of velocity. These laboratory experiments were conducted in National Oceanography Centre, Southampton by Sourav Sahoo with technical support provided by Laboratory Manager Laurence North. Sourav Sahoo interpreted the data. The hydrate formation process continued for few days and measurements were done mostly during daytime due to limited laboratory access during the night. This data set has been used for the paper published in Journal of Geophysical Research: Solid Earth (DOI 10.1029/2021JB022206)