The changes in glacial-interglacial benthic foraminferal distribution and abundance will be determined, as well as stable isotopes (carbon and oxygen), percent organic carbon, infaunal/epifaunal ratios, carbonate preservation, and planktic/benthic ratios. Benthic foraminifera will be used because their abundance and distribution patterns reflect deep-ocean conditions. Based on these patterns, the PI will attempt to reconstruct informationb (using principal component analysis) about the productivity, dissolved oxygen content and deep circulation of the glacial ocean during the past two complete glacial cycles.