sketch map of eastern sicily showing location of etna and other important structural elements of the geology of the region. faults are shown in black the volcanics of the hyblean plateau monti iblei are shown in pink color.

the late 1950s and 1960s have seen the advent of the concept of plate tectonics which is now generally accepted and appears to explain neatly a vast range of geological phenomena of the past and the present. in this framework, volcanism is basically associated with three tectonic processes
subduction. where the margins of two lithospheric plates - one oceanic, the other continental - collide, the denser, oceanic plate is thrust subducted under the lighter continental one. magmas are generated by the partial melting of subducted oceanic lithosphere that is, the rigid outer stratum of the globe, which consists of basalt covered by mainly silicic sediments which contain large quantities of water, and the resulting magmas have a high silica co...