Radiocarbon date of humic soil below the Onidake scoria fall deposit, Goto-Fukue Island, Japan

Okuno, Mitsuru*; Nagaoka, Shinji*; Kokubu, Yoko   

Onidake scoria fall deposit at Goto-Fukue Island, Japan is a product of the latest eruption of the Onidake volcano group. Radiocarbon date and C/N ratio of humic soil below the deposit are 19,840120 BP and 9.14, respectively. It shows that the soil proceeded with decomposition in part and the date might be younger than the true one. However the date is older than the result (18,090100 BP) in the soil of the same layer reported by Nagaoka and Furuyama (2004) and is consistent with stratigraphical correlation with widespread tephra such as AT and K-Ah. The calibrated date is approximately 24 cal kBP.