10Be record and magnetostratigraphy of a Miocene section from Lake Baikal: Re‐examination of the age model and its implication for climatic changes in continental Asia

We determined the concentration of the cosmogenic radionuclide 10Be in the Miocene section of a sediment core (5–12 My BP) retrieved from Lake Baikal (BDP98‐hole2) that had been previously dated by the magneto‐stratigraphic (MS) method. Using our new 10Be geochronology we reexamined the MS age‐depth assignments and found inconsistencies. We therefore reexamined the MS record and propose a new model which is consistent with the 10Be data, with an age of 8.4 My BP at a depth of 600 meters. Accepting the revised MS ages, we found the profile of the decay‐corrected 10Be concentration, which shows ca. 50% decreases of 10Be during the periods 0–2.7 My BP and 5.3–5.8 My BP. We also detected considerable increases of the 10Be flux into sediments before 4.5 My BP.