9314936 Cowan The history of our galaxy is revealed in part by the compositions of stars of various ages. Recent developments in astronomical instrumentation and in the analysis of stellar spectra have greatly increased the available information on stellar compositions. The PI will take advantage of this new information to determine the conditions required for the formation of heavy elements. He will then trace element generation throughout the history of the Galaxy. The resulting model for the chemical evolution of the galaxy will allow a new determination of the age of the heavy elements. ***