Volatile contents of Izu-Bonin Forearc volcanic glasses

Abstract

The highest H2O contents are probably the result of seawater alteration. The unaltered dacitic to rhyolitic glasses were probably quenched at low pressures corresponding to depths of 0-700m below the seafloor, also corresponding to the depths of collection of these samples, although the water depths may have been different between the Eocene and the present. The lower boninitic H2O contents in vesicular glasses suggest shallow quenching on the seafloor. -from Authors