Radiocarbon dating of deep-sea corals

Deep-sea corals are a promising new archive of paleoclimate. Coupled radiocarbon and U-series dates allow C-14 to be used as a tracer of ocean circulation rate in the same manner as it is used in the modern ocean. Diagenetic alteration of coral skeletons on the seafloor requires a thorough cleaning of contaminating phases of carbon. In addition, 10% of the coral must be chemically leached prior to dissolution to remove adsorbed modern CO2. A survey of modern samples from the full Delta(14)C gradient in the deep ocean demonstrates that the coralline CaCO3 records the radiocarbon value of the dissolved inorganic carbon.