Earth Sciences Field Trip to Sicily

March 2013

On the 23rd February 2013 the Senior Sophistor Earth Scientists set off for a week-long field trip in Sicily. The trip was designed to tie together the geological and geographical history of the area through practical experience, perfect for a course sitting on the interface between these two disciplines. It’s always beneficial to get out into the field and gain a more complete understanding of what’s taught in the lectures., and this trip did exactly that.

We were lucky enough to be visiting Sicily at a time when Mt. Etna was showing some signs of activity; the glowing red of the lava flow was a wonderful sight in the evenings from our accommodation in Catania.

During our stay in Riposto, north of Catania, we mapped historical lava flows; ventured inside an old lava tube; and examined the relationship between differing basaltic rocks, but without a doubt the geological highlight of the trip was the day we went to Monti Rossi to hunt for augite. Monti Rossi is a cinder cone that erupted in 1669. We climbed to the western summit of the cone where we found an abundance of relatively large augite crystals, most of which were euhedral. The presence of these crystals at the summit is a result of density sorting. Augite has a density of around 3.3 whereas the lava had a density lower than 2.8, and so the crystals landed closer to the vent, and thus closer to the summit. We were all down on our hands and knees to see who could find the biggest crystal – an activity that proved to be particularly enjoyable! When the hunt was over we descended the cone again and on our descent we saw some striking contacts between red and black lapilli layers. The layering demonstrated quite nicely that the red layers were oxidised before hitting the ground.

The field trip also involved work on coastal evolution. Some of the features we examined in the field included wave cut notches and trottoirs; which can both be used as potential sea level indicators. At Maddalena on the coast, we spent a few hours mapping and measuring a series of boulders. There are differing views on how these boulders were transported. Some people believe they were transported by storm waves whereas others think a tsunami event was more likely. We used our measurements to calculate the required tsunami and storm wave heights to transport the boulders. We found that the required storm wave heights went up as far as 34.25m… if it was a storm that transported the boulders then it was quite a powerful one! A tsunami seems a likely suspect, as Sicily lies on a subduction zone between the African and Eurasian plate boundaries, and so is no stranger to seismic activity.

We would like to express our gratitude to Balz Kamber and Robin Edwards for setting up and leading this trip. It was thoroughly enjoyed by all.

A group shot of the earth scientists at Monti Rossi, with Mt Etna visible through the clouds behind

Hard at work on the Turkish Steps