Validity of radiocarbon ages of Siberian yedoma

The advantages and the complications of 14C dating of organic inclusions from ice wedges by the accelerator mass spectrometry (AMS) are discussed applying to the search of true age organic material, which is simultaneous to ice-wedge formation. Radiocarbon ages of different organic materials from the same samples are compared, it is demonstrated that the difference between ages of the fractions from the ice wedges consists of about 9 kyr in Seyaha ice-wedge complex in Yamal Peninsula and about 5 kyr in Bison yedoma, Kolyma River valley. The principle of the choice of the youngest 14C age from the set and from the layer is proposed for yedoma.