Plate tectonics, radiogenic isotopic tracers and paleoceanography

The differences and similarities between the Pb and Nd revealed by our analysis emphasize their complementarity as paleoceanographic tracers. The Nd isotopes are strongly influenced by the exchange between Indian and Pacific waters, specifically by the progressive closure of the Indonesian Gateway. The closed central Pacific characteristics are defined from the extrapolation of the isotopic trend. This highlights the important role played by erosion of volcanic arcs in the Nd isotopic value of seawater. Our approach also stresses the influence of local volcanic activity (ridges or active hot spot) for lead isotopes.