This project proposes to analyze glass inclusions in quartz phenocrysts from three tin-mineralized rhyolites of western North America for volatiles and Li, Be, Rb, Cs, Y, Nb, Ba, Sr, Th, Y, Mo, W, REE's and Sn by electron microprobe, ion microprobe, and Fourier transform infrared spectroscopy. The data will be integrated with existing information on the petrology, field relations, and whole rock geochemistry to better understand the enrichment and depletion of volatiles, as well as major, trace, and ore elements in evolved magmas. The study will determine how highly-evolved magmas become differentiated, will constrain accurate values for the maximum concentrations of magmatic volatile constituents in such systems, and will relate true magmatic volatile abundances to eruptive style.
