The data are from X-ray tomographic analyses of tubular fossils. All scans were carried out using Synchrotron Radiation X-ray Tomographic Microscopy (SRXTM) except for specimen SMNH X 5324 which was also analysed using Ptychographic X-ray Computed Tomography (PXCT). The methods are described in the paper. The data consist of a stacked series of .tif files that represent maps of X-ray attenuation. The individual slices can be viewed with standard graphics software. The datasets can be studied in 3D using tomographic reconstruction software such as Avizo (www.vsg3d.com/), Spiers (www.spiers-software.org/), VG Studio Max (www.volumegraphics.com) etc. The voxel size, which is needed for scale calculations, varies between datasets and is given below. Some datasets consist of two 'blocks' of data, with slices named [specimen name]_B1 and [specimen name]_B2. These are placed in the same folder and follow on directly from one another. They can be opened together as a single dataset. The files relate to the following publication: Cunningham, J. A., Vargas, K., Liu, P., Belivanova, V., Marone, F., Martinez-Perez, C., Guizar-Sicairos, M., Holler, M., Bengtson, S. & Donoghue, P. C. J. 2015. Critical appraisal of tubular putative eumetazoans from the Ediacaran Weng'an Doushantuo biota. Proceedings of the Royal Society Series B: Biological Sciences.

Table S1.xlsx is Table S1, which contains 2D measurements of cell clusters used in Fig. 5 (this is also available from the publisher's website). The folders SMNH X 4447, SMNH X 5331 and SMNH X 5357 contain data from X-ray tomographic analyses of fossils figured in the paper: For SMNH X 5331 (the conical fossil that is the focus of the paper) there are two zip archives: 1. Slice data and Avizo files, containing: - Slice data: the raw scan data (.tif image stack) - Label files for cell clusters and individual cells: Avizo projects (.hx) containing the labels and the files required to open the project file. The cluster labels are based on a downsampled version of the data which is included here as slice data (.tif image stack). Voxel sizes for this file are 0.325 x 1.3 x 0.325 micrometers. 2. Working files, containing: - Surface models: .ply files for clusters and individual cells. - Segmented stacks: the label files as .tif stacks (voxel sizes as per slice data: 0.325 x 0.325 x 0.325 micrometres (cell labels); 0.325 x 1.3 x 0.325 micrometers (cluster labels)). SMNH X 4447 and SMNH X 5357 (two specimens figured for comparison) there is: - Slice data: zip archives of the raw scan data (.tif image stack). The individual slices (.tif images) can be viewed with standard graphics software, and the datasets can be studied in 3D using tomographic reconstruction software such as Avizo (www.vsg3d.com/), Spiers (www.spiers-software.org/), VG Studio Max (www.volumegraphics.com) etc. The Avizo project and label files (.hx and .am files) require Avizo software (www.vsg3d.com/) to be opened. The 3D models (.ply files) are widely compatible with 3D freeware packages such as MeshLab (http://meshlab.sourceforge.net/) or Blender (https://www.blender.org/), or with proprietary software, e.g. Avizo (www.vsg3d.com/), Geomagic (http://www.geomagic.com/en/), Mimics (http://biomedical.materialise.com/mimics). The files relate to the following publication: Cunningham, J. A., Vargas, K., Marone, F., Bengtson, S. & Donoghue, P. C. J. 2016. A multicellular organism with embedded cell clusters from the Ediacaran Weng'an biota (Doushantuo Formation, South China). Evolution & Development

The datasets contain 416 time-resolved synchrotron X-ray micro-tomographic images (grey-scale and segmented) of multiphase (brine-oil) fluid flow in a carbonate rock sample at reservoir conditions. The tomographic images were acquired at a voxel-resolution of 3.28 µm and time-resolution of 38 s. The data were collected at beamline I13 of Diamond Light Source, U.K., with an aim of investigating pore-scale processes during immiscible fluid displacement under a capillary-controlled flow regime, which lead to the trapping of a non-wetting fluid in a permeable rock. Understanding the pore-scale dynamics is important in many natural and industrial processes such as water infiltration in soils, oil recovery from reservoir rocks, geo-sequestration of supercritical CO2 to address global warming, and subsurface non-aqueous phase liquid contaminant transport. Further details of the sample preparation and fluid injection strategy can be found in Singh et al. (2017). These time-resolved tomographic images can be used for validating various pore-scale displacement models such as direct simulations, pore-network and neural network models, as well as to investigate flow mechanisms related to the displacement and trapping of the non-wetting phase in the pore space.

We imaged the steady-state flow of brine and decane at different fractional flows during dual injection in a micro-porous limestone using X-ray micro-tomography. We applied differential imaging on Estaillades carbonate to (a) distinguish micro-porous regions from macro-pores, and (b) determine fluid phase pore occupancy and relative permeability at a capillary number, Ca = 7.3×10-6. The sample porosity was approximately 28 %, with 7% in macro-pores and 21% in pores that could not be directly resolved (micro-porosity). We find that, in addition to brine and decane, a fraction of the macroscopic pore space contains an intermittent phase, which is occupied either by brine or oil during the hour-long scan time. Furthermore, fluid occupancy in micro-porosity was classified into three sub-phases: micro-pore space with oil, micro-pore space with brine, and micro pores partially filled with oil and brine.

H2 adsorption data on sub-bituminous coal as a function of pressure. Hydrogen flooding of a coal core. Micro CT imaging of the effect on coal swelling after hydrogen injection. Hydrogen is trapped, and no swelling is observed indicating that coal might be a good candidate for the storage of hydrogen.

A dataset is presented for defining real-time CO2 frost formation in a vertical packed column. ECT could estimate the internal permittivity distribution of the sensing area through boundary measurements. The ECT system used in this work includes sensors, data acquisition system and a computer with imaging software. The excitation signal is a sine wave with 14 Vp-p and 200k Hz frequency. One measurement electrode is chosen for excitation; other electrodes are used to acquire the signal separately. The frame rate of the ECT system is 714 frames per second. The temperature of the bed material is recorded using thermocouples and data loggers, the thermocouples are inserted into the capture column from the top of the column and are adjusted to an appropriate height above the horizontal mixed gas injector. Using the thermocouples above and below the ECT sensor helped to estimate when frost formation would be occurring within the region of bed material that the ECT sensor was measuring. The presence of this plateau in the temperature profiles identifies that CO2 frost is forming within the bed and has reached an equilibrium. We include data of ECT capacitance and temperature during the whole progress. It was found that the temperature, packing material and component of mixer gas all effect the ECT measurement. This dataset could be used to withstand extreme low temperature conditions or in desublimation processes, and its potential application to decarbonise the marine transport is significant to avoid costs if using new infrastructure for ammonia or hydrogen manufacture. Our results indicate that ECT has potential to be a novel technique for monitoring dynamic CO2 frost formation during cryogenic carbon capture. The associated report is included in the data too. Accompanying paper: Preliminary study of CO2 frost formation during cryogenic carbon capture using tomography analysis - ScienceDirect, https://doi.org/10.1016/j.fuel.2022.125271.

Results of Electrical Resistivity Tomography (ERT) conducted in Kwale County, Kenya December 2015 and June 2016 by University of Nairobi and Water Resources Management Authority as part of the Gro for GooD project (https://upgro.org/consortium/gro-for-good/) to characterize the aquifers in the study area. There were eight transects of length 1.2 to 6km, running W-E and NNE-SSW parallel to coastline. ERT data was analysed using RES2D inversion software. Gro for GooD - Groundwater Risk Management for Growth and Development

Datasets are grouped in different levels. Two main levels exist. Raw data includes processed seismic data and ERT inversion results. Seismic mass estimation relies on amplitude differences and timeshifts. ERT inversion results have been converted from VTK. • Raw *Seismic - 2009: Two datasets for Amplitude differences and Timeshifts - 2012: Two datasets for Amplitude differences and Timeshifts *ERT - 2009: One dataset with [x,y,z,Resistivity,Volume,Active] - 2012: One dataset with [x,y,z,Resistivity,Volume,Active] • Processed *Seismic - Mass_2009 - Mass_2012 * ERT - Gridded_2009 - Gridded_2012 - Seismic_ERT_Mesh_1x1 - Seismic_ERT_Mesh_1x1_CDP_Adjusted_6.25m - Seismic_ERT_Mesh_1x1_CDP_Adjusted_12.5m The dataset was created within SECURe project (Subsurface Evaluation of CCS and Unconventional Risks) - https://www.securegeoenergy.eu/. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 764531 (ENER/H2020/764531/SECURe).

The data contains three-dimensional maps of the temporal and spatial distribution of tracer concentration during miscible displacements with aqueous solutions in two cylindrical porous samples, thus including beadpack (BP) and Ketton Limestone (KL). The dynamic imaging of the displacement process was conducted using two different PET scanners, namely a Siemens Biograph 64 PET/CT for the experiments with the BP (at Imanova Ltd, UK) and a Siemens INVEON DPET for the experiments with KL (at Stanford University, USA). The experiments were carried out at flow rates, q = 10 mL/min for BP and q = 4 mL/min for KL. Each PET image represents an average over a constant time frame (45 frames of 20 seconds each for BP and 40 frames of 60 seconds each for KL). For BP, each 3D tomogram includes (128 x 128 x 111) voxels with size (1.34 x 1.34 x 2) mm3. For KL, each 3D tomogram includes (128 x 128 x 159) voxels with size (0.78 x 0.78 x 0.8) mm3. The PET dataset was used in Kurotori et al. (2018)* to characterise mm-scale dispersion during miscible displacements in these two porous media. The experimental observations of the spatio-temporal evolution of the tracer plume can also be used as a benchmark test for different numerical models for solute transport in heterogeneous porous media. Further details on the use of the PET images can be found in Kurotori et al. (2018). *T. Kurotori, C. Zahasky, S. A. Hosseinzadeh Hejazi, S.M. Shah, S.M. Benson, Measuring, imaging and modelling solute transport in a microporous limestone, Chemical Engineering Science (2018), under review.

The images in this dataset are a sample of Ketton carbonate from a micro-computed tomography (micro-CT) scan acquired with a voxel resolution of 4.52 µm. This dataset is part of a study on the effects of Voxel Resolution in a study of flow in porous media. A brief overview of this study summarised from Shah et al 2015 follows. A fundamental understanding of flow in porous media at the pore-scale is necessary to be able to upscale average displacement processes from core to reservoir scale. The study of fluid flow in porous media at the pore-scale consists of two key procedures: Imaging reconstruction of three-dimensional (3D) pore space images; and modelling such as with single and two-phase flow simulations with Lattice-Boltzmann (LB) or Pore-Network (PN) Modelling. Here we analyse pore-scale results to predict petrophysical properties such as porosity, single phase permeability and multi-phase properties at different length scales. The fundamental issue is to understand the image resolution dependency of transport properties, in order to up-scale the flow physics from pore to core scale.