Publication Date:
2019-07-17
Description:
A dry extraction method of CO2 included in glacier ice adds a contamination equivalent to 1.8 mg modern carbon for a 35 mg C sample. This enablesradiocarbon dating by accelerator mass spectrometry of 35 mg samples to about 25000 BP. Measured 14C/12C ratios are presented for a part of the Vostokice core, and for some surface samples; high 14C/12C values ranging between 65 and 105 pm C indivate in-situ 14C production during the ablation. Thereproducibility of radiocarbon dating of ice is demonstrated by results for some parts of the Caroline core, yielding an age versus depth profile, in which theage does not simply increase with depth. The results indicate that the accuracy of radiocarbon dating of ice is not limited by the statistical error arising in theaccelerator measurements, but by the uncertainty in the contamination background of the samples and by the in-situ production of 14C.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
Format:
application/pdf
