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

Authors: Cary, Lise¹; Alexandre, Anne¹; Meunier, Jean-Dominique²; Boeglin, Jean-Loup³; Braun, Jean-Jacques⁴

Source: Biogeochemistry, Volume 74, Number 1, May 2005 , pp. 101-114(14)

Publisher: Springer

Buy & download fulltext article:

Price: $47.00 plus tax (Refund Policy)

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

m 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

Document Type: Research article

DOI: http://dx.doi.org/10.1007/s10533-004-2945-1

Affiliations: 1: Europôle de l’Arbois, CEREGE, BP 80, 13545, Aix-en-Provence, France, 2: Europôle de l’Arbois, CEREGE, BP 80, 13545, Aix-en-Provence, France, Email: meunier@cerege.fr 3: LMTG, UMR 5563, 38, rue des 36 ponts, 31 300, Toulouse, France, 4: Indian Institute of Science, Indo-French Cell for Water Sciences, 560012, Bangalore, India,

Publication date: 2005-05-01