Fault properties and fluid flow patterns from Quaternary faults in the Apennines, Italy

Abstract

The study of Quaternary fault zones in the High Agri Valley (southern Italy) and in the axial zones of the central Apennines, allowed us to collect information on the permeability structure, fluid characteristics, and scaling properties of the main fault zones exposed in the area.Detailed structural mapping allowed us to derive the appropriate values of the fractal dimension characterising different active fault zone patterns and to evaluate the basic parameters needed for assessing the architecture and related permeability structure of the mapped faults. Scan line and scan area analysis helped in constraining the scaling properties of some of the attributes (i.e. fault zone thickness, fracture spacing etc.) of the main fault zones and in defining their validity range. Our results suggest that, in the Apennines, (i) extrapolation of the architectural indices of a fault zone is admissible over three orders of magnitude, and (ii) the composition of the analysed fluid inclusions and related homogenisation temperatures are associated with fault-driven fluid circulation from both superficial and deep (4–6km) levels.