Cosmogenic 10Be and 26Al dating of erratic boulders in the southern coastal area of Lake Baikal, Siberia

Cosmogenic 10Be and 26Al dating of three erratic boulders in the southern coastal area of Lake Baikal was performed using accelerator mass spectrometry (AMS) at MALT (MicroAnalysis Laboratory, Tandem accelerator) of the University of Tokyo. We examined the accuracy of our 10Be AMS measurements and the differences in scaling factors for the 10Be and 26Al production rates. The measured 10Be and 26Al ages are 15-13 and 17-11.5 kyr, respectively. The 10Be ages suggest that release of the erratic boulders from a melting glacier occurred during the Boelling/Alleroed warm period, when the land and lacustrine environments of the Baikal region changed dramatically