Finite element modelling of the recent-present deformation pattern in the Calabrian arc and surrounding regions

An attempt is made to quantify the implications of the hypothesis that the recent-present deformation pattern in the Calabrian arc and the adjacent African margin is mainly determined by horizontal tectonic forces induced by the relative convergence of the confining blocks (Africa and Adriatic). Modelling of present-day tectonic processes is carried out by means of a 2D finite element scheme involving elastic shells in a plane stress approximation. On the assumption that tectonic processes are strongly influenced by the presence of major discontinuities, the model includes zones where most deformations can concentrate. Convergent and divergent boundaries are simulated by narrow belts having elastic parameters lower than those in the surrounding regions. Transform boundaries are reproduced by orthotropic elements. Kinematic boundary conditions are imposed to simulate the relative convergence between Africa and the Adriatic. Numerical experiments show that this convergence causes the lateral escape of crustal wedges in the Calabrian arc and the adjacent African margin (Sicily). The resulting microplate kinematics can account for the complex distribution of compressional, tensional and transcurrent deformations actually observed.