Resumo

MACHADO, A. et al. Geochemical characterization of surficial sediments from the southwestern Iberian continental shelf. Cienc. mar [online]. 2005, vol.31, n.1b, pp.161-177. ISSN 0185-3880.

The impact of trace elements (Ba, Nb, Zr, Y, Sr, Rb, Pb, As, Zn, Cu, Ni, Co, Cr, V, La, Ce, Nd, Sm, Eu, Tb, Yb and Lu) transported by the Guadiana, Tinto-Odiel and Guadalquivir rivers on sediments from the southwestern Iberian continental shelf has been studied. Shelf surficial sediments from three transects established right in front of the river estuaries were characterized by specific signatures relative to those trace elements. The Guadiana transect shows high Zr concentration values; the Tinto-Odiel transect shows high heavy metal (Pb, As, Zn and Cu) concentration values; and the Guadalquivir transect shows high Sr concentration values. Data from the statistical analysis indicate three distinct sources for trace elements: lithogenic, biogenic and anthropogenic.

Palavras-chave : trace elements; rare earth elements; fine sediments; continental shelf; Iberian Peninsula.