Use of in situ-produced 10Be in carbonate-rich environments:: A first attempt

We have determined the production rate of in situ-produced Be-10 in calcite through measurements of Be-10 and Cl-36 concentrations in the same calcite samples and of Be-10 concentrations in depth profiles of flint from the same erosional surface. This yields a Be-10 production rate in calcite of 37.9 +/- 6.0 at/g/yr at sea level and high latitude, approximately sixfold higher than production in the coexisting flint. We propose that this higher rate of production may be due to high production cross sections for C spallation by cosmic rays with energies below 50 MeV. These results also open the possibility of dating burial events in carbonate-rich environments by differential radioactive decay of Be-10 and Cl-36. Copyright (c) 2005 Elsevier Ltd.