Sulfur budget in differentiated arc magmas

Sulfur compounds (H2S and SO2) constitute a major fraction of volcanic emissions, with abundance next only to H2O and CO2. Explosive eruptions can inject large amounts of sulfur into the stratosphere, inducing atmospheric perturbations that may eventually result in changes of the Earth’s average temperature. Before being released during volcanic erup- tions, sulfur can be stored in the silicate melt or in a separate fluid phase. Sulfur contained in sulfur-bearing minerals is usually not released during eruptions because the decompo- sition reactions are not efficient at the eruptive timescale. Understanding the distribution of sulfur among mineral, melt and fluid is of primary importance to determine the sulfur budget ef explosive eruptions.