The natural radiochemical and growth records in contemporary hermatypic corals from the Atlantic and Caribbean

The skeletal banding observed in vertical cross-sections of two species of coral,Montastrea annularis from Jamaica andDiploria labrynthiformis from Bermuda, has been confirmed to be annual by ingrowth of²²⁸Th towards radioactive equilibrium with²²⁸Ra taken up from seawater. In addition the Bermuda coral is shown to have incorporated²¹⁰Pb at essentially constant specific activity over at least the last thirty years.The individual annual patterns of growth banding in a suite of specimens ofD. Labrynthiformis from Bermuda are shown to be correlative. The mass of CaCO₃ accumulated each year is positively correlated with the band width for the corresponding year.