UC San Diego

We present results of measurements of cosmogenic Be-10, Al-26 and Cl-36, and the indigenous (intrinsic) concentrations of the stable elements Be, Al and Cl in 120-200 kyr old corals from Barbados and Puerto Rico. The concentration levels of these radionuclides in the corals lie in the range 10(4) to 10(8) atoms/g. A comparison of the measured nuclide concentrations with those expected to be produced in the corals by nuclear interactions of energetic cosmic radiation shows that (i) the radionuclides Al-26 and Cl-36 are derived from in situ cosmic ray interactions in the corals after their formation, but that (ii) the radionuclide Be-10 owes its provenance in the coralline lattice primarily due to incorporation of dissolved beryllium in seawater in the lattice structure of the corals. Copyright (c) 2005 Elsevier Ltd.