Quaternary tectonic activity in the north-eastern Friuli Plain (NE Italy)

Interpretation of ENI industrial seismic lines, integrated with geophysical and morphotectonic data, allowed us to reconstruct the deep geometry, kinematics and Quaternary rates of the main blind thrusts in the north-eastern corner of the Friuli Piedmont Plain. The study area is located in the eastern Friuli close to western Slovenia, where the front of Late Cretaceous - Paleogene SW-verging External Dinarides joins with the front of south-verging Neogene eastern Southalpine Chain. Instrumental and historical earthquakes show that both the Alpine and Prealpine areas bordering the plain are seismically active. Nevertheless, the seismogenic role of the main buried tectonic structures of this sector of the Friuli Plain is still not completely clear. In this study, we present four geological cross-sections which depict the buried setting of the eastern Friuli area. Through the implementation with well logs and geoelectrical data, the 3D Plio-Quaternary bottom surface was also reconstructed. By merging these new data with morphotectonic observations, the 2D geometry and kinematics of two main buried active fault systems were investigated. Quaternary and late LGM (Last Glacial Maximum) slip rates (ranging between 0.14 and 0.27 mm/yr and 0.20 and 0.38 mm/yr, respectively) were estimated.