title: Origin and Dynamics of Rare Earth Elements during Flood Events in Contaminated River Basins: Sr-Nd-Pb Isotopic Evidence.
abstract: In order to precisely quantify the contribution of anthropogenic activities and geogenic sources to the dissolved and suspended loads of rivers we have combined for the first time Rare Earth Element (REE) concentrations with Sr-Nd-Pb isotope ratios. We observed enrichments in Anthropogenic Rare Earth Elements (AREE) for dissolved (Gd) and suspended (Ce and Nd) loads of river water. During flood events, AREE anomalies progressively disappeared and gave way to the geogenic chemical signature of the basin in both dissolved and suspended loads. The isotopic data confirm these observations and shed new light on the trace elements sources. On the one hand, dissolved loads have peculiar isotopic characteristics and carry mainly limestone-derived and anthropogenic Sr and Nd as well as significant amounts of anthropogenic Pb. On the other hand, the results clearly indicate that anthropogenic contributions impact the suspended loads in all hydrological conditions. This study demonstrates that anthropogenic contributions to the river may change not only Pb but also Sr and Nd isotopic compositions in both dissolved and suspended loads. This is of importance for future provenance studies.
authors.affiliation: CAT/WATER/ERIN/LIST, 41 rue du Brill, 4422 Belvaux, Luxembourg.
authors.forename: Christophe
authors.initials: C
authors.lastname: Hissler
authors.affiliation: LHyGeS - UMR 7517 CNRS - EOST/UdS, 1 rue Blessig, 67084 Strasbourg Cedex, France.
authors.forename: Peter
authors.initials: P
authors.lastname: Stille
authors.affiliation: CAT/WATER/ERIN/LIST, 41 rue du Brill, 4422 Belvaux, Luxembourg.
authors.forename: Jean François
authors.initials: JF
authors.lastname: Iffly
authors.affiliation: CAT/WATER/ERIN/LIST, 41 rue du Brill, 4422 Belvaux, Luxembourg.
authors.forename: Cédric
authors.initials: C
authors.lastname: Guignard
authors.affiliation: LHyGeS - UMR 7517 CNRS - EOST/UdS, 1 rue Blessig, 67084 Strasbourg Cedex, France.
authors.forename: François
authors.initials: F
authors.lastname: Chabaux
authors.affiliation: CAT/WATER/ERIN/LIST, 41 rue du Brill, 4422 Belvaux, Luxembourg.
authors.forename: Laurent
authors.initials: L
authors.lastname: Pfister
mesh_terms: D004784:Environmental Monitoring; D055868:Floods; D007854:Lead; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical
chemical_list: D014874:Water Pollutants, Chemical; D007854:Lead