U/Th dating of fossil corals provides the fundamental timescale needed to evaluate the timing and rates of change of past sea level fluctuations during the Late Pleistocene. Research conducted as part of this project challenges the use of open system dating techniques and proposes to locate closed system aragonite in fossil Acropora palmata corals using novel microscopic screening and laser ablation techniques for fine-scale sampling. Fine scale analyses will attempt to better understand the magnitude and possible causes for the heterogeneities of U, Th and Pa observed within fossil coral specimens. The project will also sample fossil corals to reconstruct sea level variability during MIS 3 using material from Araki Island and Barbados, as well as to explore marine isotope stage 5 sea level estimates using the extensive archive of fossil corals that was previously collected by the PI.