Hydrogen isotopic exchange in hydrated silica glass

Abstract

Hydrogen isotopes can be a tracer of magmatism and eruption. We performed hydrogen isotope exchange experiment of water in silica glass for fundamental understanding of the hydrogen isotope exchange in silicate glass. The obtained profiles of H and D can be fitted with an error function, suggesting the diffusion-controlled hydrogen isotope exchange reaction. The isotopic exchange rate of D with H in silica glass is 1.5-2 times larger than that of H with D in the glass, implying a large isotope fractionation effect.