Barroux Gwénaël auteur aut IRD Sonke J. E. auteur aut IRD Boaventura G. auteur aut IRD Viers J. auteur aut IRD Godderis Y. auteur aut IRD Bonnet Marie-Paule auteur aut IRD Sondag Francis auteur aut IRD Gardoll S. auteur aut IRD Lagane Christelle auteur aut IRD Seyler Patrick auteur aut IRD text journalArticle eng text/pdf reformatted digital access We present a comprehensive dissolved rare earth element (REE) data set for the Amazon River and its main tributaries, Rio Negro, Solimoes, and Madeira, as well as the Curuai floodplain. The two-year time series show that REE vary seasonally with discharge in each of the tributaries, and indicate a hydrologically dominated control. Upper crust normalized REE patterns are relatively constant throughout the year, with Ce/Ce* anomalies being positively related to discharge. We propose revised annual dissolved REE fluxes to the surface Atlantic Ocean based on an integration of the seasonal data. For Nd (< 0.22 mu m) this results in an average flux of 607 +/- 43 T/yr, which is at least 1.6 times larger than the previous estimate of 374 T/yr (< 0.45 mu m) based on low water stage data. Moreover, during the high water season the maximum Nd flux measures 1277 t. yr(-1), constituting 30% of the required flux to the Atlantic Ocean (Tachikawa et al., 2003). Consequently, a smaller contribution of Nd from atmospheric and river particle desorption is required than was previously suggested. A mass balance of Amazon tributaries and observed fluxes at Obidos indicates that dissolved LREE behave quasi-conservatively. Conversely, the HREE mass balance presents a deficit during the high water stages, which could be related to the passage of water through the floodplain system accompanied by solid/dissolved phase transfer. specialized rare earth element Amazon River neodymium mass balance floodplains tributaries geochemical cycles composition of the hydrosphere major and trace element geochemistry BRESIL AMAZONIE 062 7 NIL_37-NIL_54 2006 1525-2027 https://www.documentation.ird.fr/hor/fdi:010084910 10.1029/2006GC001244 1525-2027 [F B010084910] https://www.documentation.ird.fr/hor/fdi:010084910 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2022-07/010084910.pdf IRD - Base Horizon / Pleins textes 2007-03-01 2022-07-27 fdi:010084910 fre