@article{fdi:010062040,
  title = {{I}ron isotope composition of the bulk waters and sediments from the {A}mazon {R}iver {B}asin},
  author = {{P}oitrasson, {F}. and {V}ieira, {L}. {C}. and {S}eyler, {P}atrick and {P}inheiro, {G}. {M}. {D}. and {M}ulholland, {D}. {S}. and {B}onnet, {M}arie-{P}aule and {M}artinez, {J}ean-{M}ichel and {L}ima, {B}. {A}. and {B}oaventura, {G}. {R}. and {C}hmeleff, {J}. and {D}antas, {E}. {L}. and {G}uyot, {J}ean-{L}oup and {M}ancini, {L}. and {P}imentel, {M}. {M}. and {S}antos, {R}. {V}. and {S}ondag, {F}rancis and {V}auchel, {P}hilippe},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he present study provides iron concentrations and isotopic compositions determined by multi-collector inductively coupled plasma mass spectrometry ({MC}-{ICP}-{MS}), along with key chemical, mineralogical and physical properties of 35 representative bulk (unfiltered) waters and bulk sediments from the {A}mazon {R}iver {B}asin. {T}hese samples from the {A}mazon {R}iver, five of its main tributaries (the {S}olimoes, {N}egro, {M}adeira, {T}apajos and {T}rombetas rivers) and four sub-tributaries (the {P}urus, {J}au, {U}cayali and {N}apo rivers) were essentially collected during seven field missions conducted for over two years. {T}hese encompassed the centennial flood of {M}ay 2009 and the exceptional low water stage of {S}eptember-{O}ctober 2010, thereby providing the most extreme hydrological situations that have been recorded over the last hundred years. {W}hile the data confirmed massive losses of iron (up to similar to 19000 tons/day, ca. 50% of the {A}mazon {R}iver bulk water budget) in the {S}olimoes and {N}egro rivers mixing zone, the {F}e isotope signatures of these bulk waters behaved conservatively. {T}his property allows the use of bulk water {F}e isotope signature to track iron sources and explain such isotopic signature in terms of simple mixing. {U}nfiltered samples from the organic-rich black water rivers present light delta {F}e-57 relative to the average continental crust composition. {T}his contrasts with the composition of the bulk white waters carrying a high mineral suspended load that have delta {F}e-57 values undistinguishable from the crustal isotopic signature (similar to 0.1 parts per thousand relative to {IRMM}-14). {T}his observation indicates that the {F}e isotopic composition represents a reliable direct tracer of the iron speciation and, therefore, of the host phases of iron in its sources. {S}pecifically, the white water d57{F}e most likely trace the signatures of igneous and sedimentary sources, as well as of their lateritic soil minerals, while the bulk black water d57{F}e track a preferential release of {F}e that has gone through a reduction step in the organic-rich horizons of tropical podzols as a result of the biological activity. {T}his study shows that the total iron transferred by the {A}mazon {R}iver represents between 5 and 30% of the world's ocean {F}e input by rivers, and this {A}mazon bulk water iron displays an isotopic composition indistinguishable from that of the average continental crust.},
  keywords = {{A}mazon {R}iver ; {F}e biogeochemical cycling ; {I}ron isotopes ; {F}reshwater and continental sediments ; {BRESIL} ; {AMAZONE} {BASSIN}},
  booktitle = {},
  journal = {{C}hemical {G}eology},
  volume = {377},
  numero = {},
  pages = {1--11},
  ISSN = {0009-2541},
  year = {2014},
  DOI = {10.1016/j.chemgeo.2014.03.019},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062040},
}