Valgarður: a database of the petrophysical, mineralogical, and chemical properties of Icelandic rocks

The Valgarður database is a compilation of data describing the physical and geochemical properties of Icelandic rocks. The dataset comprises 1166 samples obtained from fossil and active geothermal systems as well as from relatively fresh volcanic rocks erupted in subaerial or subaqueous environments. The database includes petrophysical properties (connected and total porosity, grain density, permeability, electrical resistivity, acoustic velocities, rock strength, and thermal conductivity) as well as mineralogical and geochemical data obtained by point counting, X-ray fluorescence (XRF), quantitative X-ray diffraction (XRD), and cation exchange capacity (CEC) analyses. The database may be accessed at 10.5281/zenodo.6980231 (Scott et al., 2022a). We present the database and use it to characterize the relationship between lithology, alteration, and petrophysical properties. The motivation behind this database is to (i) aid in the interpretation of geophysical data, including uncertainty estimations; (ii) facilitate the parameterization of numerical reservoir models; and (iii) improve the understanding of the relationship between rock type, hydrothermal alteration, and petrophysical properties.