Seasonal dissolved rare earth element dynamics of the Amazon River main stem, its tributaries, and the Curuai floodplain

被引:27
作者
Barroux, Gwenael
Sonke, Jeroen E.
Boaventura, Geraldo
Viers, Jerome
Godderis, Yves
Bonnet, Marie-Paule
Sondag, Francis
Gardoll, Sebastien
Lagane, Christelle
Seyler, Patrick
机构
[1] Univ Toulouse 3, LMTG OMP, CNRS IRD, F-31400 Toulouse, France
[2] Univ Brasilia, Inst Geociencias, BR-70910900 Brasilia, DF, Brazil
来源
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS | 2006年 / 7卷
关键词
rare earth element; Amazon River; neodymium; mass balance; floodplains; tributaries; geochemical cycles; composition of the hydrosphere; major and trace element geochemistry;
D O I
10.1029/2006GC001244
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
[1] 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.
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页数:18
相关论文
共 59 条
  • [11] SEASONAL-VARIATION IN CHEMICAL-DISTRIBUTIONS IN THE AMAZON (SOLIMOES) RIVER - A MULTIYEAR TIME-SERIES
    DEVOL, AH
    FORSBERG, BR
    RICHEY, JE
    PIMENTEL, TP
    [J]. GLOBAL BIOGEOCHEMICAL CYCLES, 1995, 9 (03) : 307 - 328
  • [12] Time scale and conditions of weathering under tropical climate:: Study of the Amazon basin with U-series
    Dosseto, A
    Bourdon, B
    Gaillardet, J
    Allègre, CJ
    Filizola, N
    [J]. GEOCHIMICA ET COSMOCHIMICA ACTA, 2006, 70 (01) : 71 - 89
  • [13] DUDDY IR, 1980, CHEM GEOL, V30, P363
  • [14] Dunne T, 1998, GEOL SOC AM BULL, V110, P450, DOI 10.1130/0016-7606(1998)110<0450:EOSBTF>2.3.CO
  • [15] 2
  • [16] THE RARE-EARTH ELEMENTS IN RIVERS, ESTUARIES, AND COASTAL SEAS AND THEIR SIGNIFICANCE TO THE COMPOSITION OF OCEAN WATERS
    ELDERFIELD, H
    UPSTILLGODDARD, R
    SHOLKOVITZ, ER
    [J]. GEOCHIMICA ET COSMOCHIMICA ACTA, 1990, 54 (04) : 971 - 991
  • [17] The use of Doppler technology for suspended sediment discharge determination in the River Amazon
    Filizola, N
    Guyot, JL
    [J]. HYDROLOGICAL SCIENCES JOURNAL-JOURNAL DES SCIENCES HYDROLOGIQUES, 2004, 49 (01): : 143 - 153
  • [18] Chemical and physical denudation in the Amazon River basin
    Gaillardet, J
    Dupre, B
    Allegre, CJ
    Negrel, P
    [J]. CHEMICAL GEOLOGY, 1997, 142 (3-4) : 141 - 173
  • [19] Rare earth elements in the Amazon basin
    Gerard, M
    Seyler, P
    Benedetti, MF
    Alves, VP
    Boaventura, GR
    Sondag, F
    [J]. HYDROLOGICAL PROCESSES, 2003, 17 (07) : 1379 - 1392
  • [20] RARE-EARTH ELEMENTS IN RIVER WATERS
    GOLDSTEIN, SJ
    JACOBSEN, SB
    [J]. EARTH AND PLANETARY SCIENCE LETTERS, 1988, 89 (01) : 35 - 47