Cenzoic Paleoceanographic and Climate Development of the Antarctic Region Based on Oceanic Sediment Sequences

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This award supports a continuing investigation of the oxygen and carbon isotopic composition and biostratigraphy of marine sedimentary sequences from the circum-Antarctic oceans. These studies are aimed at reconstructing the paleoclimatic, paleoceanographic, and biotic evolution of the Antarctic region during the Cenozoic. Oceanographic and climatic evolution since the middle Eocene (the last 52 million years) consists largely of progressive cooling and glaciation of the polar regions and perhaps warming in the tropics. The climatic and glacial evolution of polar regions, including Antarctica, is crucial to our understanding of long term global climatic change because high latitudes are among the most sensitive regions to externally driven change. Strong feedback mechanisms involving ice albedo and bottom water formation contribute to the development of polar regions. The Cenozoic marine stratigraphic record is largely the product of this climate evolution at high latitudes and hence it is crucial to have the most complete record possible. This investigation will add to the record of proxy climate and environmental indicators by using existing Ocean Drilling Program (ODP) cores. For the Paleogene (Paleocene through Oligocene), work will focus on cores from ODP Legs 113, 119, and 120. For the Neogene (Oligocene through present), work will focus on ODP cores from low and middle latitudes in the southwest and equatorial Pacific. This work will contribute significantly to a general understanding of the role of polar regions in global climatic change. In addition, this work will contribute to our understanding of the significance of the Circum-Antarctic Current in Antarctic and global climate processes. This work is particularly relevant in addressing the important question about the stability of the marine-based ice sheet of West Antarctica.