This study will be an experimental research program designed to provide data on the variables controlling the mechanical behavior of partially molten systems within the crust. The specific problem to be investigated is the production of melt by ultrametamorphism of pelitic meta-sediments, and it is hoped that the results will provide a new dimension to the interpretation of field occurrences of migmatites and granites. A primary objective is to determine how the amount (and composition) of melt produced from shists varies with temperature and water content. Of particular concern are the conditions at which the critical melt fraction is exceeded, resulting in a decrease of 10-12 order of magnitude in the effective viscosity of the magmatic suspension. The implications of these data for the dynamic behavior of various-sized anatectic zones will be explored by theoretical modeling.
