9614919 Smyth This grant provides $29,000 as one-half support of the costs of acquiring equipment to upgrade the X-ray diffraction (XRD) facility at the University of Colorado. Specifically, the equipment that will be purchased will upgrade both the single crystal and powder XRD instruments at Colorado. Two diamond anvil cells, a pressure measurement spectrometer, a high temperature, vacuum crystal mounting system, a Pentium PC and NIST Crystal Data file will upgrade the single crystal XRD for high-P/T XRD studies, while upgrade of the powder XRD will include a new computer and automated control software and the JCPDS powder diffraction CD-ROM database. A spare Mo anode will also be purchased. The PI's contributions to understanding the crystal chemistry of hydrous, high-pressure phases of silicates, notably -spinel, is of fundamental importance to understanding the global water cycle including mechanisms of water transport to the mantle within subduction zones and its effect on arc volcanism. These upgrades will greatly improve the high P/T XRD capabilities of one of the few remaining single crystal XRD facilities in the U.S. that is devoted to the Earth Sciences. ***
