Petrological monitoring of magma-mush dynamics at Stromboli: insights on the transition from mild to violent eruptive styles

Open-conduit volcanoes are found across various tectonic settings worldwide and have long captured scientific interest for their persistent yet unpredictable activity. This unexpected behaviour often represents a threat for local communities, making accurate volcanic hazard assessment essential. This PhD thesis explores, from a petrological standpoint, the processes governing the eruptive activity of Stromboli, one of the world’s most persistently active volcanoes. By combining detailed crystal analysis, isotope measurements, and diffusion modelling, this research delves into the dynamics of magma-mush interactions and their role in the transition from mild to violent eruptive styles. Textural parameterization of plagioclase crystals from eruptive products reveals that violent explosions are driven by fast magma ascent and rapid water exsolution. Mineral zoning patterns and their isotope signatures indicate that multiple generations of mushes persist in the shallow crust, where episodic magma recharge events lead to crystal recycling and the reactivation of prehistoric, high radiogenic mush components. These findings emphasize Stromboli’s ability to retain a record of past eruptions within its magmatic system, shedding light on the longevity of open-conduit basaltic systems. The results of this PhD thesis provide valuable insights for volcanic hazard assessment, highlighting the importance of petrological monitoring in forecasting volcanic activity.