Decompression Experiments on Rhyolitic Melt Embayments

This dataset presents volatile element (H2O + CO2) gradient analyses in experimentally decompressed rhyolitic melt (glass) embayments. In these experiments, natural quartz-hosted embayment glasses were re-equilibrated at high pressure (150 MPa) and temperature (780 °C) prior to controlled decompression to 10-30 MPa at various rates (0.005-0.05 MPa/s). The experiments were conducted using the cold-seal pressure vessels at the University of Oregon's Experimental Petrology and Geochemistry Laboratory, and diffusion-limited volatile gradients in glasses were analyzed by FTIR spectroscopy (Nicolet iN10 MX) at Montana State University. The purpose of this dataset is to address the longstanding need for validation of the embayment speedometer, a petrological tool that is increasingly being used to estimate magma decompression rates for explosive eruptions.