EVIDENCE FOR ENHANCED BE-10 DEPOSITION IN MEDITERRANEAN SEDIMENTS 35-KYR BP

In this letter, we report the profiles (similar to 160 samples) of Be- 10, Be-9, Zn in a Mediterranean sediment core spanning the last 60 kyr . We show the existence of a Be-10 peak, whose absolute age is estimat ed to be 34+/-3 kyr BP, based on its stratigraphic position between tw o tephra layers originating from two volcanic eruptions (Campanian Ign imbrite and Citara), dated by K-Ar, Ar-40-Ar-39 and C-14 methods. This peak is similar to the increase in the Be-10 concentration observed i n Vostok and Dome C ice cores at the same age. The increase with appro ximately similar amplitude in both ice and sediment cores at different latitudes and hemispheres cannot be explained by changes in the archi ves. The present result supports the view of a well defined global enh ancement of the Be-10 flux, related to an increase of the Be-10 produc tion rate and not to a redistribution of the Be-10 fallout between dif ferent latitudes.