Young age bias of radiocarbon dates in pre-holocene marine deposits of Hong Kong and implications for Pleistocene stratigraphy

Radiocarbon dates of pre-Holocene marine deposits in Hong Kong ranging from 21.580±1.210 to 45.700±2.000 years BP are found to be younger than uranium-series dates of mollusks and other indirect age evidence. Two mollusk samples yielded last interglacial ages of 130.500±5.300 and 142.000±20.000 years BP. respectively. Palynological and oxygen-isotope evidence shows that the marine deposits containing the mollusks were formed under marginally warmer temperature conditions than in the present day, which is consistent with a last interglacial age. Since old radiocarbon dates are likely to be minimum age estimates, similar studies carried out elsewhere would be of value to Pleistocene stratigraphy.