9417979 Nabelek This award will support a comprehensive geochemical and petrologic study of the generation of peraluminous leucogranites with focus on the Precambrian terrane in the Black Hills, South Dakota. Because petrological and geochemical relationships in the area are similar to other peraluminous leucogranite suires worldwide, the results from the study will result in a better understanding of perlauminous granite generation in general. The analytical work will include SEM and X-ray image analysis of the distribution of accessory phases, analysis of whole rocks and mineral separates for major and trace elements, analysis of minerals by electron microprobe, oxygen isotope analyses of whole rocks and minerals and possibly ICP-MS analysis of fluid inclusions. The data will be interpreted in view of published experimental studies of granite generation and theory of trace elements and isotopic behavior during crustal melting.