Rare earth elements in sediment profiles from marginal lagoons of the Moji-Guaçu River basin, Brazil.

Sediment cores from Catingueiro, Barrinha and Rio das Pedras marginal lagoons of the Moji-Guaçu River basin were analyzed for rare earth elements (REEs), Fe, Ta and Th by instrumental neutron activation analysis ( k 0-INAA). Data indicated similarities between Catingueiro and Barrinha lagoons, while a distinct scenario was seen for Rio das Pedras likely due to changes of sedimentation rate in 1950's. By using Fe, Sc, Ta and Th as conservative elements, double normalization technique was performed in order to assess the distribution pattern of Ce, Eu, La, Sm and Tb for each core. In all cases, it was evident a depletion of lighter REE elements in the Rio das Pedras lagoon. [ABSTRACT FROM AUTHOR]