Conclusions
In this paper, we highlighted how laboratory models can be used to study the subduction process. In particular, experimental results were used to relate the main geological observables available in the Central Mediterranean with the evolution of the slab into the mantle. The selected area is a key natural site because of its capability to maintain remnants of past subduction on the surface, offering the possibility of constraining the evolution of subduction for about 80 Myr.
We found that the ingredients necessary to resemble the Central Mediterranean history are the following: 1) the slow motion of the incoming African plate, dominating the first evolutionary phase, accumulated a critical amount of gravitationally unstable lithosphere to start the process; 2) balance between slab pull and lithospheric/mantle resisting forces, which, in the absence of an external kinematic engine (i.e., the low plate convergence has been always normal to the trench, minimizing its possible influence on the system), drove the exponential growth of the slab into the upper mantle and the opening of the Liguro-Provencal basin; 3) the restricted mantle convection regime and, in turn, the incapability of the slab to directly penetrate across the 660-km discontinuity, which allowed for the stagnation of the slab at depth and the episodic behavior of the trench motion/back-arc extension; And 4) land-locked paleogeographical scenarios, which enhanced the arcuature and progressive fragmentation of the subduction system.