Rapid mixing and short storage timescale in the magma dynamics of a steady-state volcano

Steady-state volcanic activity implies equilibrium between the rate of magma replenishment and eruption of compositionally homogeneousmagmas, lasting for tens to thousands of years in an open conduit system. The Present-day activity of Stromboli volcano (Aeolian Islands, Southern Italy) has long been recognised as typical of a steady-state volcano, with a shallow magmatic reservoir (highly porphyritic or hp-magma) continuously refilled by more mafic magma (with low phenocryst content or lp-magma) at a constant rate and accompanied by mixing, crystallisation and eruption. Our aim is to clarify the timescale and dynamics of the plumbing system at the establishment of the Present-day steady-state activity (<1.2ka) to pinpoint the onset of the steady-state regime. We investigated the Post-Pizzo (PP) pyroclastic sequence (∼1.7–1.5 ka) and one of the Early Paroxysms (EP) of the Present-day activity, focusingon the clinopyroxene population.