^14C测年是湖泊沉积物定年的主要方法之一,随着对过去气候环境变化的深入研究,对于湖泊样品中的年代要求更高,而不同的测年物质的^14C定年结果,会有不同的误差。通过对巴里坤湖部分样品,分别进行块状样有机质、陆生高等植物残体以及孢粉浓缩物定年比较,以探讨干旱区湖泊中^14C定年的方法。测试结果表明:孢粉浓缩物与陆生高等植物残体的测年值极为接近,在西北干旱区湖泊测年过程中,孢粉浓缩物有望成为一种可靠的测年材料。在探讨湖泊沉积物年代的"碳库"效应时,孢粉浓缩物定年可能会成为一种有效的方法。
The in-depth model study of Holocene climatic and environmental change requires more exact strata age in the lake. However,the ^14C dating of lake sediments is one of the main methods for dating,and different methods of 14C dating result in various inaccuracy. To explore more reasonable ways of 14C dating of the lakes in arid areas,based on some samples of Barkol Lake,the article compared the pollen concentrates for AMS 14C dating,the whole sample analysis method for ^14C dating and the terrestrial higher plant residues for ^14C dating. Our dating results reveal that AMS ^14C ages of the pollen concentrates are consistently 780 years older than those of the whole samples in the same layer,which is similar to the "carbon pool" effect calculated through the 14C ages of whole samples subtract the ^14C ages of terrestrial higher plant residues; for the AMS 14C ages of the pollen concentrates are very close to the 14C ages of terrestrial higher plant residues,the pollen concentrates are expected to be reliable dating material in the dating process of the lakes in arid areas.