TY - JOUR
T1 - Influence of lead-210 diffusion in radiochronology of a fresh-saltwater lake system on the Qinghai-Tibet Plateau
AU - Wang, Qiugui
AU - Wang, Jinlong
AU - Deng, Binbin
AU - Ma, Yujun
AU - Du, Jinzhou
AU - Xiao, Tangfu
N1 - Publisher Copyright:
© 2025
PY - 2025/3/1
Y1 - 2025/3/1
N2 - Lead-210 (210Pb) and caesium-137 (137Cs) have been widely employed for dating recent sediment in aqueous environments. However, their migration can limit dating accuracy. This study used 210Pbex and 137Cs to analyze sediment cores from three sites to examine the impact of post-depositional diffusion in Lake Keluke and Lake Tuosu. The results revealed significant differences in radionuclide inventories, with higher levels in K2 compared to reference soils from the Gonghe Basin. The sediment accumulation rate for K2 was determined to be 0.32 ± 0.03 g/cm2/y. Notably, K4 exhibits a diffusion profile for 210Pb and 137Cs, indicating typical post-depositional diffusion of these radionuclides. The diffusion coefficients of 210Pb and 137Cs in K4 were calculated to be 0.48 ± 0.07 cm2/y and 0.32 ± 0.05 cm2/y, respectively, which are comparable to values reported in other sediment profiles. These coefficients are influenced by redox conditions and organic matter mineralization. The results highlight the importance of using multiple dating methods to improve the accuracy of sediment accumulation rate estimates, particularly in environments where diffusion processes are significant. This study represents the first case study on the distribution of diffusion profiles for 137Cs and 210Pbex in non-accumulating sediments from the Qinghai-Tibet Plateau Lakes. Our findings are expected to enhance understanding of radionuclide behavior in lake sediments and provide valuable insights for sediment dating.
AB - Lead-210 (210Pb) and caesium-137 (137Cs) have been widely employed for dating recent sediment in aqueous environments. However, their migration can limit dating accuracy. This study used 210Pbex and 137Cs to analyze sediment cores from three sites to examine the impact of post-depositional diffusion in Lake Keluke and Lake Tuosu. The results revealed significant differences in radionuclide inventories, with higher levels in K2 compared to reference soils from the Gonghe Basin. The sediment accumulation rate for K2 was determined to be 0.32 ± 0.03 g/cm2/y. Notably, K4 exhibits a diffusion profile for 210Pb and 137Cs, indicating typical post-depositional diffusion of these radionuclides. The diffusion coefficients of 210Pb and 137Cs in K4 were calculated to be 0.48 ± 0.07 cm2/y and 0.32 ± 0.05 cm2/y, respectively, which are comparable to values reported in other sediment profiles. These coefficients are influenced by redox conditions and organic matter mineralization. The results highlight the importance of using multiple dating methods to improve the accuracy of sediment accumulation rate estimates, particularly in environments where diffusion processes are significant. This study represents the first case study on the distribution of diffusion profiles for 137Cs and 210Pbex in non-accumulating sediments from the Qinghai-Tibet Plateau Lakes. Our findings are expected to enhance understanding of radionuclide behavior in lake sediments and provide valuable insights for sediment dating.
KW - Diffusion coefficient
KW - Inventory of Pb and Cs
KW - Lake sedimentation rate
KW - Pb and Cs
KW - Qinghai-Tibet Plateau
UR - https://www.scopus.com/pages/publications/85217429141
U2 - 10.1016/j.scitotenv.2025.178645
DO - 10.1016/j.scitotenv.2025.178645
M3 - 文章
C2 - 39946879
AN - SCOPUS:85217429141
SN - 0048-9697
VL - 967
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 178645
ER -