The role of elongated pores and crystals of lavas influences their mechanical and physical behaviour, providing a first microstructural clue. In the context of a doctoral project, two samples – a trachyte and a basalt/andesite (s.l.) - representative of Fogo Volcano (S. Miguel Island, Azores, Portugal) were collected as part of an intact rock study. They were microstructurally assessed in the INGV-OV (Naples) using the ZEISS Xradia Versa 410 X-ray computed microtomography to obtain high-resolution 3D images, as well as to perform real-time in-situ mechanical tests (uniaxial – 7 mm diameter cylinders - and Brazilian – 13 mm diameter discs) to assess how elongated pores/crystals control strength. In addition to 3D images of the samples, which allow segmentation of the pore space and crystals, mechanical tests show that trachytes are more competent than vesicular basalts/andesites. Both pores and crystals control the development of the crack pattern.
The role of the physical and microstructural properties of lavas impacts the dynamics of magma ascent and of the volcanic edifice itself. In the context of a doctoral project, ten samples representative of the central volcanoes of S. Miguel Island (Azores, Portugal), priorily collected in available outcrops in the island, were microstructurally assessed for the first time in the INGV-OV (Naples). Imaging was processed by the ZEISS Xradia Versa 410 X-ray computed microtomography. This tool enables accurate and complete textural characterization of rocks by providing 3D images of the samples. Posteriorly, the rocks were analysed with a dedicated image analysis software to resolve the internal microstructure of the samples. determining several key properties (porosity, permeability, fracturation, and crystal content) that are of major relevance for a posterior physical and mechanical assessment.
This publication results from work conducted under the transnational access/national open access action at magLab, INGV-OV (Naples, Italy) supported by WP3 ILGE - MEET project, PNRR - EU Next Generation Europe program, MUR grant number D53C22001400005.
This data publication is related to the article of Buono et al. (2025) and contains the results of 4D X-ray microtomography investigations of well rocks from the Campi Flegrei caldera conducted at the micro-CT laboratory of the Istituto Nazionale di Geofisica e Vulcanologia-Osservatorio Vesuviano, part of EPOS TCS Multi-Scale Laboratories. 3D X-ray images were acquired before and after compression experiments and were combined with time-resolved 2D X-ray images taken during both indirect tensile and compression tests, which are also complemented by the experimental raw data. 3D scans with higher resolution of samples before compression experiments are also provided.
Samples refer to rocks cored from SV1 (40.8483°N, 14.1209°E), the deepest and most centrally located exploratory geothermal well within the Campi Flegrei caldera.
Related projects: INGV Progetto Dipartimentale LOVE-CF, PON-GRINT, PNRR (National Recovery and Resilience Plan) funded project MEET, Horizon 2020 projects EXCITE and EPOS.