9508616 Leger The Department of Mineral Sciences at the American Museum of Natural History (AMNH) and Department of Geological Sciences (LDEO) of Columbia University will establish a joint electron microprobe laboratory. This development builds upon numerous pre- existing links between these departments such as a joint program of Graduate Studies, research collaboration, and shared use of experimental petrology, x-ray, and FTIR laboratories. AMNH will acquire of a new electron microprobe to replace the 18-year old ARL SEMQ in current operation and to provide LDEO researchers with added capabilities in the analysis of light elements and in image analysis processing not currently possible with their 10- year old Cameca MBX. This grant supports half of the $800,000 capital cost of a new Cameca electron microprobe and half will be supported equally by AMNH and Columbia University. In addition, AMNH supports a full-time Ph.D.-level research position (the PI) to manage the facility. Replacing the two aging microprobes with a single state-of-the-art instrument has advantages for efficiency of operation, full utilization of the analytical facility, cost efficiency of internal operation, and maximizing the use of scarce instrumentation dollars. The new instrument will lead to increased productivity and analytical capability for multiple investigators at both institutions and in the New York metropolitan area including students from the City University of New York (CUNY) system. A single laboratory has the additional advantage that it will bring scientists from AMNH and LDEO closer together and encourage new intellectual links. ***