Although not volcanic, the deformation is absolutely tectonic. The African plate is subducting under the European plate. That's the volcanism around Santorini, Etna, Stromboli, Vesuvius and Campi Flegrei, and the uplift raising the Alps. Rock on Matterhorn's southern, Italian flanks is African granitic gneiss.





Summit looking down, Swiss side on left, Italian side on right.