The U-series component-dating method has been employed to date the sediment core B-194 from Balikun Lake. 230Th/ 232Th and 234U/ 232Th ratios in various components of the samples dissolved in different concentration a...The U-series component-dating method has been employed to date the sediment core B-194 from Balikun Lake. 230Th/ 232Th and 234U/ 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 B-194 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 deep-sea δ 18O SPECMAP also demonstrates that the U-series component-dating method can be used to date lake sediments.展开更多
文摘The U-series component-dating method has been employed to date the sediment core B-194 from Balikun Lake. 230Th/ 232Th and 234U/ 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 B-194 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 deep-sea δ 18O SPECMAP also demonstrates that the U-series component-dating method can be used to date lake sediments.
