A new approach to unravel pre-eruttive processes in volcanic systems

Constraining the timescales of pre-eruptive magmatic processes in active volcanic systems is paramount to understand magma chamber dynamics and the triggers for volcanic eruptions.

Temporal information of magmatic processes is locked within the chemical zoning profiles of crystals but can be accessed by means of elemental diffusion chronometry.

Mineral compositional zoning testifies to the occurrence of substantial temperature differences within magma chambers, which often bias the estimated timescales in the case of multi-stage zoned minerals.

The published paper propose a new Non-Isothermal Diffusion Incremental Step model to take into account the non-isothermal nature of pre-eruptive processes, deconstructing the main core-rim diffusion profiles of multi-zoned crystals into different isothermal steps. The Non-Isothermal Diffusion Incremental Step model represents a significant improvement in the reconstruction of crystal lifetime histories. Unravelling stepwise timescales at contrasting temperatures provides a novel approach to constraining pre-eruptive magmatic processes and greatly increases our understanding of magma chamber dynamics.

This publication is the result of a long-term collaboration between the authors (i.e. Istituto di Geoscienze e Georisorse of Florence, University of Florence and Natural and History Museum of London) focused on the study of the plumbing system dynamic in active volcanic systems. The aim was to propose a general method useful to all scientists who deal with elemental diffusion studies, to “easily” resolve the appropriate diffusion equations and calculate the timescales of magmatic process.

In particular the idea came from a still on going research on the present day steady state volcanic activity of Stromboli volcano, aimed at further constraining the timescale of recharge and eruption trigger in the shallow plumbing system from the recent to the present day activity by diffusion evaluation of compositionally zoned clinopyroxene crystals.

Full reference: Petrone C.M., Bugatti G., Braschi E., Tommasini S. (2017). Pre-eruptive magmatic processes re-timed using a non-isothermal approach to magma chamber dynamics. NATURE COMMUNICATIONS | 7:12946 | DOI: 10.1038/ncomms12946 |www.nature.com/naturecommunications 1.