A Tour of Italy's Fiery Trio

A VOLCANIC FAMILY WITH COMPLEX PERSONALITIES

- MARK LEATHERMAN

In May of 2019, my wife and I were able to enjoy our honeymoon, two weeks in Italy. It marked my first ever trip into Europe, and I could not skip the opportunity to accomplish another first, seeing my first stratovolcanoes up close and in person! After a great amount of convincing from my non-rockhounding new bride, we were able to book sightseeing time with Italy’s “big three,” Vesuvius, Etna, and Stromboli. Not only are these the only three active volcanoes in Europe, but they also have a very complex story to tell once one delves into their behavior and their constituent rocks.

MOUNT VESUVIUS

In starting our honeymoon in Venice, we proceeded to head southward with our final stop being the island of Sicily. After a memorable jaunt to Rome, our next stop was Naples, the primary base for visiting the historic town of Pompeii and the mountain responsible for its infamous sudden demise in 79 A.D. via a pyroclastic cloud.

We started our morning with an awe-inspiring tour of Pompeii’s ruins led by a graduate student of archaeology, Francesca, from the University of Naples. This cataclysm is primarily controlled by the fact that Vesuvius is classified as a composite volcano (a.k.a. stratovolcano). These volcano types occur at subduction zones, where a thin, but heavy oceanic plate subducts under a thicker, more buoyant continental plate. In this case, it is the African Plate subducting under the Eurasian Plate. Evaporating water from the down-going oceanic plate interacts and lowers the melting point of the mantle wedge above, creating magma that ascends to the surface.

Since said magma has incorporated the water vapor needed for melt generation, as well as other key elements and gases during its rise, eruptions associated with subduction are typically on the explosive side.