This award supports a detailed geological investigation of the Sirius Formation, Antarctica, in order to determine: 1) its relation to alpine glaciers and ice sheets; 2) its age and stratigraphy; and 3) the source of the enclosed marine microfossils. The results of this research will provide a critical test for the leading hypotheses of the origin of the Sirius Formation and, thereby, contribute significantly to resolving Antarctic Ice Sheet response to Tertiary climate warmth. Given the important role that the Antarctic Ice Sheet plays in global climate, this new knowledge will significantly aid resolution of global-scale paleoclimate problems, principally by constraining interpretation of the deep sea oxygen-isotope record. This data will also permit the testing and tuning of ice sheet models.