Title of article :
Sedimentation rates and trace metal input history in intertidal sediments from San Simón Bay (Ría de Vigo, NW Spain) derived from 210Pb and 137Cs chronology
Author/Authors :
Paula ?lvarez-Iglesias، نويسنده , , Bego?a Quintana، نويسنده , , Belen Rubio، نويسنده , , Marta Pérez-Arlucea، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2007
Abstract :
210Pb and 137Cs 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) 210Pb 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 210Pb 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 137Cs 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.
Keywords :
210Pb , 137Cs , Intertidal sediments , GEOCHEMISTRY , heavy metal
Journal title :
Journal of Environmental Radioactivity
Journal title :
Journal of Environmental Radioactivity