9317458 Berg This award supports a petrological, geochemical, and geochronological study of volcanics from the Balleny Islands, one of two localities of ocean island basaltic volcanism on the Antarctic plate. Petrographic analyses of thin sections will determine modal minerals, which will yield information about depth of magma origin, and will aid in determining the extent of alteration. Analytical work will include major and trace element analyses, isotopic analyses for the Pb, Sr, and Nd systems, as well as K-Ar and 40Ar/39Ar geochronological data. These data will be used, along with other ocean island basalt data, to constrain the composition of mantle chemical reservoirs during the time of production of the magmas. When added to other databases, these data will contribute to a better understanding of the geographic extent of mantle reservoirs and the correlation of these reservoirs in the southern hemisphere. ***