Gas-water partition and gas channelling along Rn-HeCO2 bearing faults

The work discusses Rn and He data collected during surveys performed simultaneously in different types of natural occurrence located along faults bearing pressurised CO2 (Siena basin, Central Italy). The obtained results emphasize the effects of gas-water partition and gas channelling processes induced by faults on Rn and He distribution in near-surface environment; accordingly they suggest that the analysis of a single-sub-system of the geologic environment may provide data not representative of gas occurrence or abundance in the investigated site