Data consist of electron microprobe, SEM, ICP-MS in laser and solution mode, and images of crystal mounts and thin sections, La Palma 2021. 35 samples of basalt, erupted during the 2021 Cumbre Vieja eruption on La Palma, Canary Islands, were collected in February 2022. The basalt samples were prepared for various kinds of analysis: powdered for ICP-MS (whole rock trace elements including chalcophile elements), made into thin sections for petrological analysis (imaged and mapped using Scanning Electron Microscope), and crushed and crystals picked and mounted for targeted microanalysis of melt inclusions, crystals using Electron Probe Microanalysis (EPMA, for major elements and volatiles S, Cl and F) and laser ablation ICP-MS (for trace elements including chalcophile elements). The overall aim of the project was to look at the chalcophile element abundance and distribution in the magmas feeding the eruption. The data here relate to a NERC Exploring the Frontiers project.

These are data pertaining to Wadsworth et al. (2022) which are published here: https://doi.org/10.1016/j.jvolgeores.2022.107672. How: Samples were set in epoxy and ground to the point where half of the glass chips collected were ground away. Then the sample was turned around and the other half of the particles were ground away until a thin slice of the chips remained at about 0.05 mm thick. At this point, the thin slices of volcanic chips were measured using Fourier Transform Infrared How: Spectroscopy (FTIR) at JAMSEC (Japan) by Iona McIntosh in collaboration with coauthors and Fabian Wadsworth. The data are the primary data in this manuscript. These data were collected to investigate how much water is remnant in particles that are known to have formed by the competition between degassing of H2O and sintering in volcanoes. That competition has implications for the development and destruction of permeability, which is at the core of this project.