This project involves the experimental determination of mineral- melt equilibria in felsic systems as functions of pressure, temperature, water content, and minor element concentrations. Particular emphasis will be placed on the role of minor elements (aluminum, iron, and magnesium) which lend distinctive signatures to felsic magmas and which may serve to distinguish important aspects of their evolutionary histories. Natural hydrous minerals (biotite, hornblende, muscovite) will be added to quartz-feldspar compositions to test their stability ranges and breakdown reactions and the compositions of coexisting liquids. The results of these experiments will help to constrain the compositional variability of felsic liquids and magmas as functions of source composition and conditions of generation, will test the viability of mafic rocks as sources of primary trndhjemitic magmas, and will constrain the range of conditions over which epidote and muscovite can coexist with magmatic liquids.
