Fig. 3: Nd and Hf isotopic composition (εNd, εHf) and concentration distributions along the salinity gradients of the three estuarine transects.
Distributions of dissolved concentrations and isotopic compositions of Nd and Hf along the north Amazon transect (a, b), the south Amazon transect (c, d) and the Pará transect (e, f). The solid lines in each panel represent the predicted conservative mixing lines between the river water and seawater endmembers for concentrations and isotopic compositions, respectively. The dashed lines above and below the corresponding solid lines reflect the uncertainties of the estimations of the εNd and εHf endmember values. Error bars correspond to the 2 standard deviations of the εNd and εHf measurements. The second conservative mixing line (green dashed line) for Nd and Hf is defined by water samples corresponding to the maximum removal percentage and the seawater endmembers.
