Evidence for enhanced ¹⁰Be deposition in Mediterranean sediments 35 kyr BP

Abstract

In this letter, we report the profiles (∼160 samples) of 10 Be, 9 Be, Zn in a Mediterranean sediment core spanning the last 60 kyr. We show the existence of a 10 Be peak, whose absolute age is estimated to be 34±3 kyr BP, based on its stratigraphic position between two tephra layers originating from two volcanic eruptions (Campanian Ignimbrite and Citara), dated by K‐Ar, 40 Ar‐ 39 Ar and 14 C methods. This peak is similar to the increase in the 10 Be concentration observed in Vostok and Dome C ice cores at the same age. The increase with approximately similar amplitude in both ice and sediment cores at different latitudes and hemispheres cannot be explained by changes in the archives. The present result supports the view of a well defined global enhancement of the 10 Be flux, related to an increase of the 10 Be production rate and not to a redistribution of the 10 Be fallout between different latitudes.