Last‐Glacial to Post‐Glacial 10Be fluctuations in a sediment core from the Academician Ridge, Lake Baikal

Abstract

10Be concentrations, sediment composition and sediment accumulation rates were determined in a sediment core from the Academician Ridge of Lake Baikal. The 10Be concentrations vary from 5.07 × 108 atoms/g in the last glacial section to 11.25 × 108 atoms/g in the section representing the post‐glacial climate stage. 10Be fluxes, on the other hand, increase toward the last‐glacial stage coinciding with an increase of the sediment accumulation rate. These facts imply that climate‐related sedimentation is related to both flux and concentration of the nuclide in the sediment core. During the last‐glacial stage, arid conditions in the lake's watershed caused a marked increase in flux of clay particles with low 10Be content to the lake, resulting in an increased flux but lowered concentration of 10Be in the sediments. It is suggested that the 10Be record of the bottom sediments of Lake Baikal can be used as a proxy indicator of climate change in central Asia.