CONTINENTAL weathering and mid-ocean-ridge hydrothermal circulation are the two main processes that release dissolved silicon to the ocean. It has been hypothesized1 that temporal variations in the relative strengths of these two processes might be estimated from the Ge/Si ratio of opal in marine sediments, because the chemistry of germanium is similar to that of silicon2–5. We analysed river water from the Orinoco basin and soils from Venezuela and Panama for germanium and silicon, to determine the relationship between river Ge/Si ratios, drainage basin lithology and chemical-weathering intensity. Our results, presented here, indicate that chemical-weathering intensity, defined as the fraction of original bedrock silicon dissolved during continental weathering, is related to the Ge/Si ratio in river water and is inversely related to river silicon concentrations. Changes in global climate, sea level or patterns of plate-tectonic interactions could change chemical-weathering intensity and complicate the interpretation of the marine opal Ge/Si record.
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Froelich, P. N. & Andreae, M. O. Science 213, 205–207 (1981).
Cotton, F. A. & Wilkinson, G. Advanced Inorganic Chemistry (Wiley-Interscience, New York, 1972).
Froelich, P. N., Hambrick, G. A., Andreae, M. O., Mortock, R. A. & Edmond, J. J. geophys. Res. 90, 1133–1141 (1985).
Mortlock, R. A. & Froelich, P. N. Geochim. cosmochim. Acta 51, 2075–2082 (1987).
Murnane, R. J., Leslie, B., Hammond, D. A., Stallard, R. F. Geochim. cosmochim. Acta 53, 2873–2882 (1989).
Bernstein, L. R. Geochim. cosmochim. Acta 49, 2409–2422 (1985).
Martin, J. M. & Meybeck, M. Marine Chem. 7, 173–206 (1979).
Stallard, R. F. in The Chemistry of Weathering (ed. Drever, J. I.) 293–316 (Reidel, Dordrecht, 1985).
Stallard, R. F. in Physical and Chemical Weathering in Geochemical Cycles (eds Lerman, A. & Meybeck, M.) 225–246 (Kluwer Academic, Dordrecht, 1988).
Stallard, R. F. & Edmond, J. M. J. geophys. Res. 88, 9671–9688 (1983).
Stallard, R. F. & Edmond, J. M. J. geophys. Res. 92, 8293–8302 (1987).
Murnane, R. J. thesis, Princeton Univ. (1988).
Novokahatskiy, I. P., Kalinin, S. K. & Zamuayina, G. M. Geochem. Int. 4, 1192–1196 (1967).
Meybeck, M. Rev. Geol. Dyn. Geogr. Phys. 21, 215–246 (1979).
Mortlock, R. A. & Froelich, P. N. Science 231, 43–45 (1986).
Murnane, R. J. & Stallard, R. F. Paleoceanography 3, 461–469 (1987).
Andreae, M. O. & Froelich, P. N. Analyt. Chem. 553, 287–291 (1981).
Schneider, W. A. Jr & Sandell, E. B. Mikrochim. Acta 2, 263–268 (1954).
About this article
Cite this article
Murnane, R., Stallard, R. Germanium and silicon in rivers of the Orinoco drainage basin. Nature 344, 749–752 (1990). https://doi.org/10.1038/344749a0
Variations of trace elements under hydrological conditions in the Min River, Eastern Tibetan Plateau
Acta Geochimica (2018)
Environmental Science and Pollution Research (2018)
Subcellular localization of silicon and germanium in grass root and leaf tissues by SIMS: evidence for differential and active transport
Reviews in Environmental Science and Bio/Technology (2009)