Abstract:

Rock petrophysical properties shape a wide range of geological processes and strongly influence the suitability of rock for geothermal energy production and carbon sequestration. In past decades, Orkustofnun and ÍSOR led extensive investigations into rock properties, obtaining ~500 samples derived from 'fossil' geothermal systems exposed by erosion as well as younger rocks from the Neovolcanic zone. We sought to expand upon this valuable database (named Valgarður after the late Valgarður Stefánsson, reservoir physicist at Orkustofnun), adding 627 samples and ~9000 additional measurements from both historical and more recent studies. The database illuminates key petrophysical properties, such as porosity, permeability, grain density, rock strength, electrical resistivity, and acoustic wave velocities, and the interplay between these properties and alteration processes. Furthermore, the dataset can be used to parameterize numerical models and aid in the interpretation of geophysical data. It is freely available and archived here.