Task 2.2.2. Dating of permafrost samples

Sediment samples for DNA analysis collected from permafrost dominated regions were submitted for radiocarbon dating when judged to be within the age-range for this technique (0-50,000 years). Older material was dated using other techniques:  optially-stimulated luminescence [OSL], Uranium series, and via the presence of volcanic ash deposits of known age. Undated samples within otherwise well dated, continuous sediment sequences were assigned estimated ages using numerical models.
Over 400 samples have been dated, with ages ranging from modern soil samples through to samples that date from before the previous interglaciation (>25,000 years ago).  The samples cover the whole of the last glacial-interglacial cycle. There is particularly good coverage for the period of the last glacial maximum (height of the last ice age ~15,000-25,000 years ago) and the period of less extreme climate ~50,000-25,000 years ago.