9530279 Freeman The PIs will reconstruct curves of the magnitude of isotopic fractionation by marine plankton during Neogene using delta 13-C of prymnesiophyte-derived long-chain ketones (alkenones) and planktonic carbonate phases. If climate colling is driven by a decline in atmospheric CO2, then on a global scale isotopic fractionation should also decrease. The isotopic proxy method of reconstructing pCO2 will prove useful to evaluate climate change over large temporal and geographic scales during the early Neogene.
