Biogeochemistry

, Volume 74, Issue 1, pp 101–114 | Cite as

Contribution of phytoliths to the suspended load of biogenic silica in the Nyong basin rivers (Cameroon)

  • Lise Cary
  • Anne Alexandre
  • Jean-Dominique Meunier
  • Jean-Loup Boeglin
  • Jean-Jacques Braun
Article

Abstract

Particulate biogenic silica (BSi) carried by rivers to estuaries and marine sediments is generally assumed to be primarily composed of diatoms. Phytoliths – biogenic opal formed in plants – are found in some marine sediments where they are interpreted to be the result of atmospheric and river inputs. In this study, we evaluate the contribution of phytoliths to the suspended load of rivers of the Nyong basin (Cameroon). BSi (2 μm to 2 mm fraction) in the soils and the rivers range respectively, from 0.9 to 3.9 wt% and from 1.3 to 4 wt%. About 90% of the BSi pool in both soils and river suspended load are composed of phytoliths. Thecamoebians and fresh water diatoms are minor components. The concentrations of BSi and the phytolith assemblages show great similarities between the waters and the soil samples. This result implies that the erosion of top soils is the major source of the suspended load, in good agreement with the transport-limited weathering regime of the study basin.

Keywords

biogenic silica phytolith weathering erosion Cameroon 

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Copyright information

© Springer 2005

Authors and Affiliations

  • Lise Cary
    • 1
    • 2
  • Anne Alexandre
    • 1
  • Jean-Dominique Meunier
    • 1
  • Jean-Loup Boeglin
    • 3
  • Jean-Jacques Braun
    • 4
  1. 1.Europôle de l’ArboisCEREGEAix-en-ProvenceFrance
  2. 2.UR de Géochimie des sols et des eauxINRAAix-en-Provence, cedex 4France
  3. 3.LMTGUMR 5563ToulouseFrance
  4. 4.Indian Institute of Science, Indo-French Cell for Water SciencesBangaloreIndia

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