Theme 1: Production of magma and assembly of volcanic plumbing systems

Volcanoes are fed by magmas that are sourced at depth by partial melting of the mantle and/or partial melting of the crust. Determining the composition and mineralogy of the sources as well as the respective contribution of juvenile and crustal components remain important challenges to our understanding of the petrogenesis of magmas. Before reaching the Earth’s surface, magmas are transferred through a network of reservoirs, sills, and dykes, where they are subjected to a range of processes including mixing, mingling, contamination, fractionation. As magmas stall in the crust, their dynamics and evolution strongly depend on their physical state; i.e. liquid-dominated magma reservoirs vs solid-dominated crystal mushes. Exsolution of volatiles upon the crystallization of anhydrous phases or decompression further modify their physical and thermal properties. A significant proportion of magmas solidifies in the crust, forming intrusive rocks, whereas a small fraction may eventually reach the surface. The convoluted history between source and surface determines the final composition and, to some extent, the rheology, ultimately controlling the dynamics of the eruption.

We invite sessions that address the production of magmas, the processes that govern the assembly and evolution of the crustal magma plumbing system, and how the journey of magmas between source and surface influences the dynamics of eruptions.

Theme leaders: Catherine Annen, Olivier Namur, Chris Huber