Apennine Mountains crust undergoes “unzipping” process

Geologists led by Stefano Tavani from the University of Florence have identified a mechanism explaining the unusual geological activity beneath the Apennines in Italy. The research suggests the Earth's crust is undergoing a process described as “unzipping” or delamination.

This process involves the separation of the dense lower crust and lithosphere from the upper layers, causing the detached portions to sink into the Earth's mantle. This movement creates a moving “hinge” or front that shifts toward the Adriatic foothills, similar to the opening of a zipper.

The study explains why the Apennine mountain range exhibits contradictory movements: while the outer edge of the range is compressing, the crust further inland is stretching. This phenomenon was previously a geological puzzle, as the compression and stretching appeared to occur simultaneously in a convergent mountain belt. Researchers used seismic data, GPS measurements, and satellite radar observations to confirm that these deformations are concentrated around the Mohorovičić discontinuity, the boundary between the crust and the mantle.