Volcano Etna

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 g ......