Volatiles are extremely important in magmatic systems and control many properties of the system including: viscosity, liquidus and solidus temperatures, diffusion rates, and eruption processes. Yet very little of our knowledge about the amount and types of volatiles come from direct measurements. This study proposes to determine volatiles in magmas by measuring the volatile content in glass inclusions in minerals by infrared techniques, along with microprobe studies. The evolution of a gas phase will be monitored by determining the C1/F of associated apatites. Samples used for this study will be minerals separated from glassy pumice samples from five chemical zoned ash-flow sheets that have been collected previously, and detailed geochemical and mineralogical data. The infrared studies will be done at Lawrence Livermore National Laboratory on their sate of the art Fourier transform infrared spectrometer attached to a microscope. ***//
