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

Abstract

An attempt is made to quantify the implications of the hypothesis that the recent-present deformation pattem in the Calabrian arc and the adjacent African margin is mainly determined by horizontal tectonic forces in- duced by the relative convergence of the confining blocks (Africa and Adriatic)- Modelling of present-day tec- tonic processes is carried out by means of a 2D finite element scheme involving elastic shells in a piane stl-ess approximation- On the assumption that tectonic processes are strongly influenced by the presencc of major di,- continuitie", the model includes zones whcre most deformations can concentl-ate Convcrgent and divcrgcnt boundaries are simulated by narrow belts having elastic parameters lower than those in the surrounding regions, transform boundaries are reproduced by orthotl-opic elements, Kinematic boundary conditions are im- po,ed to simulatc the relative convergence between Africa and the Adriatic, Numerical experimcnts show that this convergence causes the lateral escape of crustal wedgcs in the Calabrian arc and the adjacent African mar- gin (Sjcily). The resulting microplate kinematics can account for the complex distribution of compressional, tensional and transcurrent deformations actually observed.