Chlorine (Cl) and hydrogen chloride (HCl) solubility in hydrous silicate melts: implications for volcanic gas composition

Abstract Chlorine is a key volatile in magmatic and volcanic systems, being a major consumer of atmospheric ozone and an important ligand for metal transport. Despite chlorine’s importance however, the combined effects of melt composition and H₂O on Cl solubility and HCl degassing remain poorly constrained, particularly at magmatic pressures. We present high-pressure (0.5–1.63 GPa), 1200 °C experiments on hydrous andesite, dacite and rhyolite (up to ~ 8–9 wt% H₂O) equilibrated with Ag–AgI–AgCl b