MULTI-PROXY ANALYSIS OF MIDDLE PLIOCENE NORTH ATLANTIC SEA SURFACE TEMPERATURE

Understanding surface ocean conditions in high and low latitude regions of the North Atlantic is critical to the analysis of middle Pliocene oceanic circulation and to the evaluation of potential forcing of global middle Pliocene warming. The North Atlantic region has the highest density of middle Pliocene SST estimates based on quantitative analyses of planktic foraminifer assemblages. Other fossil groups (e.g., ostracodes, pollen, dinoflagellates, etc.) provide information on surface conditions that support the foraminifer-based estimates. We will present a detailed re-evaluation of middle Pliocene planktic foraminifer assemblages and derived SST estimates from key sites in the North Atlantic as well as preliminary estimates of surface conditions based on Mg:Ca analyses of planktic foraminifers. Comparisons among SST estimates based on foraminifer transfer function, Mg:Ca foraminifer shell chemistry, and published alkenone data will also be presented.