33 Advances in Subsurface Characterization for Energy Exploration and Utilization

Advances in the characterization of the subsurface for applications in both oil and gas, and geothermal energy (conventional, AGS, and EGS), carbon capture and storage (CCS), energy storage, and other low-carbon technologies.

Wednesday, 20 May 2026
8:00 AM - 10:20 AM
Alvarado A

X-ray Imaging and Comprehensive Characterization of Mafic-Ultramafic Rocks for Advancing In-Situ Hydrogen Generation Projects

Paper number: 33-1
Program: Technical Sessions
Time: 8:05 AM – 8:25 AM

Authors

Abstract

Mafic-Ultramafic rocks have started playing a central role in natural and engineered hydrogen generation through serpentinization and related redox reactions. A detailed understanding of their mineralogical composition, microstructure, and fluid–rock pathways is therefore critical for scaling-up in-situ hydrogen generation projects. In this work, we integrate X-ray micro-computed tomography imaging with comprehensive petrological and geochemical characterization to quantify key rock properties controlling hydrogen production potential. CT resolved mineral spatial distributions without affecting rock sample integrity. These data are complemented by thin-section petrography, Scanning Electron Microscopy (SEM) paired with Energy-Dispersive X-ray Spectroscopy (EDS), and bulk geochemical analyses to constrain mineralogy, alteration textures, and iron oxidation states. The combined dataset enabled direct linkage between microstructural features, reactive surface area, and geochemical reactivity of selected mafic-ultramafic lithologies. Results demonstrate a significant contrast between homogenous dunite samples and highly heterogeneous pyroxene-rich peridotites. Similarly, the studied rocks vary in porosity, alteration intensity, and their mineral assemblages, implying variability in fluid access and hydrogen generation efficiency. Our integrated X-ray–based characterization framework not only reduces geological uncertainty but also provides a robust foundation for designing and parameterizing emerging in-situ hydrogen generation strategies, paving the way for field demonstrations.

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Geological Society of America Abstracts with Programs. Vol. 58, No. 4

doi: 10.1130/abs/2026RM-410548

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