Pejo fault system: an example of multiple tectonic activity in the italian Eastern Alps

The Pejo fault in the Italian Eastern Alps is a major sinistral transtensional fault. It marks the boundary between basement units displaying contrasting thermal histories, with Alpine (i.e., Mesozoic–Cenozoic) cooling ages preserved in the footwall juxtaposed against Variscan (i.e., Carboniferous– Permian) age in the hanging wall. Structural investigations, together with fission-track analysis, confirm a Late Cretaceous age for the Pejo fault, which excludes any direct kinematic contribution of the Pejo fault to the late Oligocene–Neogene evolution of the central-eastern segment of the Periadriatic fault. However, our results establish the importance of a major early Oligocene north-south to…