This award provides matching funds that will be applied toward the purchase of a new generation, sensitive, high- resolution ion microprobe to be installed and operated in the Department of Earth and Planetary Sciences at the University of California, Los Angeles. UCLA is committed to matching more than 50% of the acquisition costs of this equipment. The need to better understand the evolution of the Earth and its natural resources requires continual advances in the ability to characterize the geochemical properties of Earth materials, and isotope geochemistry in particular has made outstanding contributions by permitting age dating of materials and events in Earth history and the use of isotope tracers for delineating the transfer of material during both local- and global-scale processes. The new generation instrument to be acquired through this award will extend existing capabilities in the U.S. for isotopic analysis of Earth materials by permitting micron-scale, in-situ, isotopic analyses with detection limits in the part per billion range. The instrument will be the centerpiece of a facility that will be open to earth scientists outside of UCLA and will permit the fullest application of recent instrumental developments to a better understanding of the origin and evolution of the crust and the genesis of mineral resources.