9707153 Halliday This award provides partial funding (50%) for improvements to the instrumentation of the Radiogenic Isotope Geochemistry Laboratory housed in the Department of Geological Sciences at the University of Michigan. The University of Michigan is committed to providing the remaining funds necessary. The Radiogenic Isotope Geochemistry Laboratory is involved in a wide range of research requiring modern geochemical instrumentation including studies of the origin of the solar system, the early differentiation history of the Earth, the accretion history of other planets, the tectonic history of the Grenville Province, and the chemical composition of the Earth's mantle. The improvements to the laboratory's instruments will include acquisition of a direct injection nebulizing system for the laboratory's plasma-source mass spectrometer and an ultraviolet laser ablation system. ***