Received: 19 Aug 2014 – Accepted for review: 11 Oct 2014 – Discussion started: 05 Nov 2014
Abstract. The main problem of radiocarbon dating within permafrost is the uncertain reliability of the 14C dates. Syngenetic sediments contain allochthonous organic deposit that originated at a distance from its present position. Due to the very good preservation of organic materials in permafrost conditions and numerous re-burials of the fossils from ancient deposits into younger ones the dates could be both younger and older than the true age of dated material. The strategy for the most authentic radiocarbon date selection for dating of syncryogenic sediments is considered taking into account the fluvial origin of the syngenetic sediments. The re-deposition of organic material is discussed in terms of cyclic syncryogenic sedimentation and also the possible re-deposition of organic material in subaerial-subaqueous conditions. The advantages and the complications of dating organic micro-inclusions from ice wedges by the accelerator mass spectrometry (AMS) method are discussed applying to true age of dated material search. Radiocarbon dates of different organic materials from the same samples are compared. The younger age of the yedoma from cross-sections of Duvanny Yar in Kolyma River and Mamontova Khayata in the mouth of Lena River is substantiated due to the principle of the choice of the youngest 14C date from the set.
How to cite. Vasil'chuk, Y. K. and Vasil'chuk, A. C.: Strategy of valid 14C dates choice in syngenetic permafrost, The Cryosphere Discuss., 8, 5589–5621, https://doi.org/10.5194/tcd-8-5589-2014, 2014.
The strategy of valid 14С dates choice in syngenetic permafrost includes several points such as:
• Re-deposition of organic matter in the permafrost is common. Syngenetic sediments contain allochthonous organic deposit that originated at a distance from its present position. There needs to be a careful cull of the manifestly more ancient 14C dates.
• The youngest 14C date from the data set in the particular horizon is closest to the actual time of accumulation and freezing of the yedoma
The strategy of valid 14С dates choice in syngenetic permafrost includes several points such...