9526162 Wolf The goal of this project is to continue studying the behavior of lithophile elements in magmatic systems and specifically to investigate experimentally the distribution of halogens between halogen-bearing minerals and coexisting silicate liquids. This proposal focuses on the some of the chemical parameters controlling the distribution of halogens between silicate liquids and biotite, amphibole, apatite, and titanite. With proper assessment of these parameters, these minerals may eventually be able to be used as direct monitors of halogen concentrations within evolving magmatic-hydrothermal systems. Such knowledge us of great value in determining the ability of halogens to act as fluxes and mineralizers during the formation of granite-associated magnetic-hydrothermal ore deposits and, more generally, to control other fundamental parameters such as liquid structure, viscosity, and density, phase relationships, and diffusion, speciation, and liquid/fluid/crystal partitioning of elements. This is a collaborative project involving undergraduate students at Augustana College and researchers at the University of Oklahoma.