Volumetric µCT and Spectroscopic Dataset for the Taphogeochemical Study of the Eoguptioxylon antiqua Holotype

This dataset comprises the volumetric and spectroscopic evidence underpinning the taphogeochemical reconstruction of the holotype of Eoguptioxylon antiqua Crisafulli & Lutz, 2007, from the Upper Permian La Antigua Formation (Paganzo Basin, Argentina). The archive includes:• Calibrated X-ray microcomputed tomography (µCT) volumetric stacks (5.002 µm isotropic voxel size), orthogonal reslices, and segmentation masks isolating ferruginous mineralisation loci (goethite).• Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR–ATR) spectra (4000–450 cm⁻¹) identifying the mineral paragenesis (silica polymorphs, goethite, analcime, and calcite).• Quantitative grey-value profiles resolving growth-ring periodicity and fluid migration pathways.• Petrographic photomicrographs (PPL/XPL) providing cross-validation of mineral phases and textural heterogeneity against volumetric attenuation contrasts. These data document a multistage diagenetic sequence—initial ferruginous impregnation, progressive silicification (chalcedony → opal-CT → quartz), and late-stage analcime/cementation—within a volcaniclastic-influenced fluvial–alluvial setting. The dataset supports non-destructive, three-dimensional characterisation of permineralised seed-plant woods and is provided under a CC BY 4.0 licence to facilitate reproducibility and comparative taphogeochemical studies in Gondwanan palaeobotany.