Variations in the biologic productivity and ocean circulation over the last 3 million years will be studied using 1350 samples taken from two ODP sites on the Ontong-Java Plateau. Measurements will include 1)preservation and relative abundances of key planktonic and benthic foraminifera; 2)d-018 for overall stratigraphic control and vertical temperature gradients; and 3) d-C13 for history of changes in carbon chemistry. Of particular interest will be the nature of the variations in these indices during critical glacial- interglacial transitions. Other points of interest will be the history of upwelling/productivity in the western equatorial Pacific, the link between preservation spikes and abrupt ice melting, and the history of Pacific-Atlantic assymetry in the age of deep water. The link will be made between "true" global average signal and climatic cycles measured in the North Atlantic.
