9304304 Dyar This is a research program on experimental study of the mechanical behavior of upper mantle rocks. From an understanding of the way in which hydrous species partition at upper mantle conditions it will be possible to interpret mechanical property measurements. The proposed program will include static experiments on aggregates of mantle minerals under high pressure and temperature conditions, infrared measurements to characterize the partitioning of water-derived species between the phases, and Mossbauer spectroscopy measurements to monitor changes in the iron valence during uptake of water. ***
