Alvarez-Iglesias Paula, Quintana Begoña, Rubio Belén, Pérez-Arlucea Marta
Departamento de Geociencias Marinas y Ordenación del Territorio, Facultad de Ciencias del Mar, Universidad de Vigo, 36310 Vigo (Pontevedra), Spain.
J Environ Radioact. 2007;98(3):229-50. doi: 10.1016/j.jenvrad.2007.05.001. Epub 2007 Jul 5.
(210)Pb and (137)Cs dating methods, accompanied by a high-resolution geochemical study, were applied to intertidal sediments containing both fine and coarse-grained particles and also, anthropogenic Pb in order to establish sedimentation rates and historical trends in heavy metal input. Sedimentation rates were established according to the "Constant Flux:Constant Sedimentation" (CF:CS) (210)Pb dating model, which was preferred rather than the "Constant Rate of Supply-Minimum Variance" (CRS-MV) model. Variations in sediment grain-size were accounted for by application of several normalization procedures. Al was selected for grain-size correction. Corrected sedimentation rates obtained from (210)Pb dating were corroborated through a second independent radionuclide tracer and by comparison of peak trace metal inputs into the environment with peaks in the sediment. The Chernobyl maximum was identified in the normalized (137)Cs activity profile. Sedimentation rates of 6.2+/-1.2 mm y(-1) and 3.1+/-0.5 mm y(-1) for the upper (two muddy layers) and 6.0+/-2.0 mm y(-1) for the lower (sandy) intertidal mud flat deposits of San Simón Bay were determined. According to the established chronology, human-induced environmental changes were detected in total metal concentrations (Cu, Pb, Zn) and in sediment grain-size and composition.
将²¹⁰Pb和¹³⁷Cs测年方法与高分辨率地球化学研究相结合，应用于含有细颗粒和粗颗粒以及人为铅的潮间带沉积物，以确定沉积速率和重金属输入的历史趋势。沉积速率是根据“恒定通量：恒定沉积”（CF:CS）²¹⁰Pb测年模型确定的，该模型比“恒定供应速率 - 最小方差”（CRS - MV）模型更受青睐。通过应用几种归一化程序来考虑沉积物粒度的变化。选择Al进行粒度校正。通过第二种独立的放射性核素示踪剂以及将环境中痕量金属输入峰值与沉积物中的峰值进行比较，证实了从²¹⁰Pb测年获得的校正沉积速率。在归一化的¹³⁷Cs活度剖面中识别出切尔诺贝利最大值。确定了圣西蒙湾上部（两个泥层）潮间带泥滩沉积物的沉积速率为6.2±1.2 mm y⁻¹，下部（砂质）潮间带泥滩沉积物的沉积速率为3.1±0.5 mm y⁻¹，以及6.0±2.0 mm y⁻¹。根据已建立的年代序列，在总金属浓度（Cu、Pb、Zn）以及沉积物粒度和组成中检测到了人为引起的环境变化。
