U-series dating on late Quaternary sediments from Balikun Lake

The U-series component-dating method has been employed to date the sediment core B₁94 from Balikun Lake.²³⁰Th/²³²Th and²³⁴U/²³²Th ratios in various components of the samples dissolved in different concentration acids were measured respectively. The results indicate that there is a good relationship of the isotopic ratios between the solutions and the residues, and that uranium and thorium isotopic fractionations did not occur during acid leaching. Based on the U-series ages obtained by using component-dating method, a 144-ka time sequence was established corresponding to the upper 25-m interval of the B₁94 core, which is in agreement with palaeomagnetic dating results. The fact that the palaeoclimatic and palaeoenvironmental record labeled with U-series ages is correlative with the deepsea °¹⁸O SPECMAP also demonstrates that the U-series component-dating method can be used to date lake sediments.