This award provides 50% partial funding for the acquisition of a thermal ionization mass spectrometer to be installed and operated in the Department of Geology at the University of Maryland. The University is committed to providing the remaining funds. The instrument is to be used primarily in the conduct of research on the chemical evolution of the Earth's crust and mantle and in investigations of the origin of noble metal ores. The isotopic systems to be analyzed by mass spectrometry include rhenium-osmium, samarium-neodymium, uranium-lead-thorium, rubidium- strontium, lithium, and boron.