Geostatistical analysis for the assessment of rare-gas soil distribution in detecting concealed faults. The Ofanto clay basin

An integrated geochemical, morphological and structural analysis was applied to a clay basin in Southern Italy (Ofanto valley) to delineate tectonic features. The resulting distribution of previous soil-gas survey and the location and orientation of field-observed brittle deformations were compared with air-photo interpreted morpho tectonic features. The results show that the highest helium and radon values occur preferentially along elongated features shown by meso structural and geo morphological analysis. Geostatistical analysis of the geochemical data combined with the other geological techniques has been shown to improve the interpretation of soil-gas results for neotectonic studies in clay basins where tectonic discontinuities have no surface expression